bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3417: Snail and serpinA1 promote tumor progression and predict prognosis in colorectal cancer
Authors: Kwon Chae Hwa , Park Hye Ji , Lee Ja Rang , Kim Hye Kyung , Park Do Youn
Published: August 2015

Purpose: Snail and serpin peptidase inhibitor clade A member 1 (serpinA1) are involved in tumor progression. In this study, we investigated the role of Snail and serpinA1 in colorectal cancer (CRC) and examined the mechanisms through which these proteins mediate CRC progression.

Experimental Design: Tumors from 528 patients with CRC were examined to determine the clinicopathological significance of Snail and serpinA1 expression. Cell migration and invasion were assessed to determine the functional roles of Snail and serpinA1. Snail binding to the serpinA1 promoter was analyzed by chromatin immunoprecipitation (ChIP) assays.

Results: Immunohistochemical analysis of 528 samples from patients with CRC showed that elevated expression of Snail or serpinA1 was correlated with advanced stage, lymph node metastasis, and poor prognosis. Moreover, we detected a correlation between Snail and serpinA1 expression. Functional studies performed using the CRC cell lines DLD-1 and SW-480 showed that overexpression of Snail or serpinA1 significantly increased CRC cell invasion and migration. Conversely, knockdown of Snail or serpinA1 expression suppressed CRC cell invasion and migration. ChIP analysis revealed that Snail regulated serpinA1 by binding to its promoter. In addition, fibronectin mediated Snail and serpinA1 signaling and was involved in CRC cell invasion and migration.

Conclusion: Taken together, our data showed that Snail and serpinA1 promoted CRC progression through fibronectin. These findings suggested that Snail and serpinA1 were novel prognostic biomarkers and candidate therapeutic targets in CRC.

Note: This abstract was not presented at the meeting.

Citation Format: Chae Hwa Kwon, Hye Ji Park, Ja Rang Lee, Hye Kyung Kim, Do Youn Park. Snail and serpinA1 promote tumor progression and predict prognosis in colorectal cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3417. doi:10.1158/1538-7445.AM2015-3417
Abstract 3424: The efficacy of Gasdermin gene family for tumor marker in colorectal cancer
Authors: Orita Hajime , Tanaka Shigekazu , Watanabe Shunsuke , Matsuzawa Hirokazu , Mizuguchi Konomi , Ito Tomoaki , Senuma Koji , Kushida Tomoyuki , Sakurada Mutsumi , Maekawa Hiroshi , Wada Ryo , Sato Koichi
Published: August 2015

Gasdermin (GSDM/Gsdm) family was originally identified as a candidate causative gene for a mouse skin mutation, recombination induced mutation 3 (Rim3). It has four human homologs, GSDMA, GSDMB, GSDMC, and GSDMD. All GSDM family members are located in amplicons, genomic regions often amplified during cancer development, and are considered to be involved in the regulation of epithelial apoptosis. GSDMA is mainly expressed in the upper gastrointestinal tract. In contract, GSDMD is expressed in the colorectal tract.

In this study, we researched those expressions in colorectal cancer and evaluated them for tumor marker, comparing between those expressions and clinical pathological status.

We immunohistologically analyzed both expressions of GSDMA and GSDMD, using thirty colorectal cancer cases which were surgically treated at our institution 2013-2014 (Stage1 10 cases, Stage2 10 cases, Stage3a 10cases). Thenretrospectively analyzed the connection, between GSDM expression and clinicopathological data.

GSDMA was no expressed in normal colorectal epithelium, but was overexpressed gradually rising in carcinoma.

However, GSDMD showed the opposite results compared with GSDMA.

The results of the expression analysis suggested that GSDMA and GSDMD act antagonictically with each other in the clinical stage of colorectal cancer.

Citation Format: Hajime Orita, Shigekazu Tanaka, Shunsuke Watanabe, Hirokazu Matsuzawa, Konomi Mizuguchi, Tomoaki Ito, Koji Senuma, Tomoyuki Kushida, Mutsumi Sakurada, Hiroshi Maekawa, Ryo Wada, Koichi Sato. The efficacy of Gasdermin gene family for tumor marker in colorectal cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3424. doi:10.1158/1538-7445.AM2015-3424
Abstract 343: The homeobox gene DLX4 promotes inflammatory signaling and peritoneal metastasis of ovarian cancer
Authors: Haria Dhwani , Trinh Bon Q. , Ko Song Yi , Barengo Nicolas , Naora Honami
Published: August 2015

The lethality of ovarian cancer stems from the propensity of the disease to involve the peritoneal cavity. However, the mechanisms that drive peritoneal metastasis of ovarian cancer are poorly understood. We previously identified that high expression of the homeobox gene DLX4 in ovarian cancer is strongly associated with advanced disease stage and reduced survival. In this study, we identified that DLX4 stimulates the attachment of ovarian cancer cells to mesothelial cells that line the peritoneal cavity. DLX4 induced expression of the cell adhesion molecule CD44 which interacts with hyaluronic acid, a glycosaminoglycan that is produced by peritoneal mesothelial cells. Neutralization of CD44 abrogated the ability of DLX4 to stimulate tumor-mesothelial cell interactions. The induction of CD44 expression by DLX4 was found to be largely due to the ability of DLX4 to transcriptionally activate the gene encoding the pro-inflammatory cytokine interleukin-1beta (IL-1beta) which in turn stimulated the nuclear factor kappa B (NF-kB) signaling pathway. Furthermore, inhibition of IL-1beta or of NF-kB activity abrogated the stimulatory effect of DLX4 on tumor-mesothelial cell interactions. This study provides insights into the mechanisms of inflammatory signaling and peritoneal metastasis of ovarian cancer, and raises the possibility that targeting inflammatory signaling might be a strategy for treatment of advanced-stage ovarian cancer.

Citation Format: Dhwani Haria, Bon Q. Trinh, Song Yi Ko, Nicolas Barengo, Honami Naora. The homeobox gene DLX4 promotes inflammatory signaling and peritoneal metastasis of ovarian cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 343. doi:10.1158/1538-7445.AM2015-343
Abstract 3459: A new promising drug through abating endoplasmic reticulum stress response in treating endometrial cancer
Authors: Wang Chao , Guo Wei , Mills Gordon B. , Lu Yiling
Published: August 2015

Background: In order to survive under ER stress conditions, cells have a self-protective mechanism against ER stress, which has been termed the ER stress response. BIP/HSPA5 is a well-known marker of ER stress. In multiple tumors, BIP expressed highly, which even confers resistance to of chemotherapeutic agents. Some methods targeting to BIP have been studied to enhance chemotherapy efficacy. CBIO showed the most relative proteins with BIP is YAP-pS127. Objects: try to understand what roles YAP plays in ER stress and to explore a new drug for endometrial cancer taking advantage of ER stress. Methods: to analyze the YAP and YAP-pS127 level as well as HSPA5 mRNA level of EC patients. Then, overexpression of YAP, proteasome inhibitors and YAP inhibitor were employed to explore the relationship between YAP and BIP by immunoprecipitate (IP), western blot (WB) and SRB techniques and to investigate the most effective combination of drugs cell. Results: 1. 322 EC patients with G3 had higher HSPA5 level and lower YAP-pS127 level compared with G1-2, patients with higher HSPA5 level had lower YAP-pS127 level. 12 EC patients had higher HSPA5 level than 12 normal women. 2. MG132 and Bortezomib induced ER stress successfully with the increase of BIP, CHOP,PERK, IRE-1a. 3. Overexpression YAP also increased the BIP, CHOP and IRE-1a level. However, Verteporfin(VP) as a YAP inhibitor decreased IRE-1a level, moreover offset the effect of MG132 on increasing IRE-1a. 4. VP induced the death of EC cells in a dose and time course manner. The sequential method of VP- Carboplatin or VP-Taxol is most effective than the simultaneous method of VP+ Carboplatin or VP+ Taxol. Conclusion: BIP impacted the grade of EC and correlated with YAP-pS127 negatively in EC. The YAP could contribute to the occurrence of ER stress. VP destroyed the capacity of ER stress response of EC cell so that it induced cell to die effectively. Making failure of ER stress response before chemotherapy will enhance the effectiveness of chemotherapeutic drugs.

Citation Format: Chao Wang, Wei Guo, Gordon B. Mills, Yiling Lu. A new promising drug through abating endoplasmic reticulum stress response in treating endometrial cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3459. doi:10.1158/1538-7445.AM2015-3459
Abstract 3461: RSK2 is a driver of estrogen receptor positive breast cancer
Authors: Ludwik Katarzyna , Lannigan Deborah
Published: August 2015

For unknown reasons, high levels of active Ser/Thr protein kinase RSK in estrogen receptor α (ERα)-positive (ER+) breast cancer patients correlate with better responsiveness to anti-estrogen therapies. Investigation of these surprising observations led us to discover an unanticipated mechanism in which ERα controls RSK2 nuclear accumulation. RSK2 is retained in the nucleus by physical association with ERα and this interaction is disrupted by anti-estrogen treatment. Consistent with these findings, in primary human ER+ breast tissue organoids, 4-hydroxy-tamoxifen (4-OHT) drove export of RSK2 to the cytoplasm. Importantly, RSK2 nuclear accumulation is critical for the expression of the oncogene, cyclin D1. This conclusion is supported by the observations that a RSK2 mutant, which cannot accumulate in the nucleus, does not rescue cyclin D1 in cells silenced for endogenous RSK2. Analysis of RNAseq data shows that ERα and RSK2 cooperatively regulate a transcriptional program, which includes cyclin D1. The physiological relevance of these conclusions is supported by our observations that in ∼60% of ER+ breast cancer patients, active nuclear RSK correlates with ERα and cyclin D1 levels. Taken together, these findings suggest that responsiveness to endocrine-based therapy is driven by reduced RSK2 nuclear accumulation, which in turn reduces expression of cyclin D1 and of other tumor-promoting effectors. Based on these observations we hypothesized that nuclear RSK2 cooperates with ERα and is a physiologically relevant driver of ER+ breast cancer. To test this hypothesis we generated a transgenic mouse model in which the MMTV promoter controls expression of RSK2 fused with the nuclear localization signal (NLS) of SV40. Strikingly, in ∼50% of transgenic mice forced nuclear accumulation of RSK2 in the mammary gland caused hyperplasia and ductal carcinoma in situ (DCIS). These results are the first demonstration that RSK2 can drive proliferation and transformation in vivo. Transgenic animals had a 4-fold increase in the number of cyclin D1 expressing cells and a 6-fold increase in Ki67 levels. Surprisingly, in vivo expression of nuclear RSK2 expanded the population of ER+ cells. These results demonstrate, for the first time, that nuclear RSK2 drives the amplification of the cell population relevant to ER+ breast cancer. In agreement with these observations we found that overexpression of ERα in the mouse mammary gland expands exclusively, by ∼3 fold, the cell population that co-expresses ERα and active nuclear RSK. These results further support our hypothesis that RSK2 cooperates with ERα and is an important drug target for ER+ breast cancer.

Citation Format: Katarzyna Ludwik, Deborah Lannigan. RSK2 is a driver of estrogen receptor positive breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3461. doi:10.1158/1538-7445.AM2015-3461
Abstract 3474: The effect of forced expression of k-ras mutation on gastrointestinal cancer cells and IGF-IR targeting therapy
Authors: Adachi Yasushi , Matsunaga Yasutaka , Sasaki Yasushi , Nosho Katsuhiko , Yamamoto Hiroyuki , Arimura Yoshiaki , Endo Takao , Kato Yasuo , Tokino Takashi , Carbone David P. , Shinomura Yasuhisa
Published: August 2015

Background & Aims: Mutation in k-ras plays important roles in both the progression and the resistance for anti-EGFR therapy in gastrointestinal tumors. Insulin-like growth factor-I receptor (IGF-IR) signaling is required for carcinogenicity and proliferation of many tumors. We have previously shown successful therapy for gastrointestinal cancer cell lines with k-ras mutation using recombinant adenoviruses expressing dominant negative IGF-IR (IGF-IR/dn) and an anti-IGF-IR monoclonal antibody. In this study, we sought to evaluate the effect of k-ras mutation on gastrointestinal cancer cell lines and IGF-IR targeting therapies for those cells. Methods: We made stable transfectants of mutated k-ras in gastrointestinal cancer cell lines. We assessed the effect of forced expression of mutated k-ras on proliferartion, apoptosis induction, migration, and invasion in gastrointestinal cancer cell lines. Then we assessed the anti-tumor effect of IGF-IR/dn on mutated k-ras transfctomas. Results: Overexpression of mutated k-ras let gastrointestinal cancer cell lines be more agrressive phenotypes, such as more proliferative, more anti-apoptotic, more movable, and more invasive. IGF-IR/dn inhibited cell growth, colony formation, migration, and invasion, but induceed apoptosis of gastrointestinal cancer cells with or without mutated k-ras expression. Conclusions: K-ras mutation might be inportant for progressive phonotype in gastrointestinal cancers. IGF-IR might be a good molecular therapeutic target for gastrointestinal cancers even if k-ras is mutated.

Citation Format: Yasushi Adachi, Yasutaka Matsunaga, Yasushi Sasaki, Katsuhiko Nosho, Hiroyuki Yamamoto, Yoshiaki Arimura, Takao Endo, Yasuo Kato, Takashi Tokino, David P. Carbone, Yasuhisa Shinomura. The effect of forced expression of k-ras mutation on gastrointestinal cancer cells and IGF-IR targeting therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3474. doi:10.1158/1538-7445.AM2015-3474
Abstract 3475: Diurnal suppression of EGFR signaling by glucocorticoids: implications for tumor progression and treatment
Authors: Lauriola Mattia , Enuka Yehoshua , Zeisel Amit , D'Uva Gabriele , Roth Lee , Carvalho Silvia , Solmi Rossella , Domany Eytan , Yarden Yosef
Published: August 2015

Signal transduction by receptor tyrosine kinases (RTKs) and nuclear receptors for steroid hormones is essential for body homeostasis, but the crosstalk between these receptor families is poorly understood. We observed that activation of GR, a steroid hormone receptor that binds glucocorticoids, inhibits the transcriptional response downstream to EGFR signaling, an RTK. The underlying mechanism entails suppression of EGFR's positive feedback loops, such as ligands and simultaneous triggering of negative feedback loops that normally restrain EGFR. Our animal studies reveal that the regulation of EGFR's feedback loops by glucocorticoids translates to circadian control of EGFR signaling: EGFR signals are suppressed by high glucocorticoids during the active phase, while EGFR signals are enhanced during the resting phase. Consistent with this pattern, treatment of animals bearing EGFR-driven tumors with a specific kinase inhibitor was more effective if administered during the resting phase of the day, when glucocorticoids are low. These findings support a circadian clock-based paradigm in cancer therapy.

Citation Format: Mattia Lauriola, Yehoshua Enuka, Amit Zeisel, Gabriele D'Uva, Lee Roth, Silvia Carvalho, Rossella Solmi, Eytan Domany, Yosef Yarden. Diurnal suppression of EGFR signaling by glucocorticoids: implications for tumor progression and treatment. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3475. doi:10.1158/1538-7445.AM2015-3475
Abstract 3476: Intermittent anti-androgen monotherapy: a possible treatment for androgen receptor-overexpressing prostate cancer
Authors: Oliver Tim , Berney Dan , Shaw Greg
Published: August 2015

A case report of a Gleason 4+4 patient who self-medicated on intermittent flutamide with 14 cycles of 3 months on 3 months off, surviving at 14 years.cast doubt on conventional wisdom that intermittently androgen blockade should include an LHRH blocking agent. Anti-androgen(aa) monotherapy was thought to be dangerous as on treatment testosterone rises. It was speculated that he had been Testosterone(T) deficient at diagnosis as in many patients with high grade tumours and had benefited from the blocking action of the aa to control tumour expansion while allowing the off period to allow T to differentiate the tumour possibly by suppressing an over expressed androgen receptor. Following this case others already on AA continuously were recruited to our then ongoing phase 1/2 study of intermittent hormone therapy(Lane 2004).

This abstract records their outcome and compares it with those treated with conventional GNRH monotherapy or maximum androgen blockade

Results: Between 1997 and 2007 111 patients sort advice about intermittent hormone therapy having started on some form of endocrine treatment. 46 MO patients received GNRH regime and 33 receive aa monotherapy (M0 = 31). Provided PSA was below 4 they were eligible for entry. Median pre-treatment PSA was 22 (range 0.4-237) compared to 22 (range 3.7-402) in MO GNRH groups. Over all survival was 87% ,at 5 year and 78% at 8 years and continuing to respond on protocol 66% at 5 yrs, 57% at 8 compared to 77/56% at 5 and 54/41% at 8 years in M0 GNRH treated group

Conclusion: Non-randomised selection in this cohort makes it difficult to draw strong conclusions. As overall survival is significantly better than with GNRH regimens, an exploratory randomised phase 2 trial comparing GNRH against aa monotherapy in patients presenting with over expression of androgen receptor and below normal age-corrected serum testosterone is under consideration

Citation Format: Tim Oliver, Dan Berney, Greg Shaw. Intermittent anti-androgen monotherapy: a possible treatment for androgen receptor-overexpressing prostate cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3476. doi:10.1158/1538-7445.AM2015-3476
Abstract 3479: CPX-351 (cytarabine:daunorubicin liposome for injection) anti-leukemia activity is potentiated by Chk1 inhibition
Authors: Vincelette Nicole D. , Karnitz Larry M. , Karp Judith E. , Smith Douglas B. , Hess Allan D. , Mayer Lawrence D. , Kaufmann Scott H.
Published: August 2015

Background: Cytarabine and an anthracycline, the mainstay of AML therapy, affords a five-year survival below 30%. Accordingly, there is a continuing need for improved AML therapies. CPX-351 encapsulates within liposomes a fixed 5:1 molar ratio of cytarabine and daunorubicin that is synergistic (in vitro) and markedly improved in anti-leukemic activity (in vivo). Promising evidence of improved remission and survival rates with CPX-351 compared to standard of care treatments has also been observed clinically and a pivotal Phase 3 trial is currently ongoing. Because Chk1 inhibition has been shown to enhance the actions of both cytarabine and anthracyclines, there has been interest in assessing the effect of CPX-351 when combined with Chk1 inhibitors. Here we describe the evaluation of CPX-351 alone and in combination with the Chk1 inhibitors MK-8776 and LY2603618 in AML cell lines and in clinical AML samples ex vivo. Methods: Effects of CPX-351 on Chk1 phosphorylation and cell cycle distribution in the human AML lines U937 and HL-60 were analyzed by immunoblotting and flow cytometry. Effects of Chk1 inhibitors on CPX-351-induced apoptosis were assessed by flow cytometry after propidium iodide staining (DNA cleavage), Hoechst staining (nuclear fragmentation) and colony formation in soft agar (long-term survival). Effects CPX-351 ± MK-8776 on clinical AML samples were assayed using clonogenic assays. Results: Treatment of U937 cells with CPX-351 resulted in phosphorylation of Chk1 on Ser317 and Ser296 (sites of ATR-mediated phosphorylation and autophosphorylation, respectively) as well as S phase slowing consistent with Chk1 activation. Co-treatment of AML cell lines with Chk1 inhibitors + CPX-351 resulted in increased apoptotic morphological changes and DNA fragmentation as well as diminished clonogenic survival compared to CPX-351 alone. The CPX-351/MK-8776 combination displayed enhanced antiproliferative effects against some clinical AML isolates ex vivo compared to CPX-351 alone, with additional assays ongoing. Conclusions: Collectively, these results show that Chk1 inhibition enhances the cytotoxicity of CPX-351 in AML cell lines and some clinical AML samples, offering the possibility that CPX-351 may be well suited for combining with such molecularly targeted agents.

Citation Format: Nicole D. Vincelette, Larry M. Karnitz, Judith E. Karp, Douglas B. Smith, Allan D. Hess, Lawrence D. Mayer, Scott H. Kaufmann. CPX-351 (cytarabine:daunorubicin liposome for injection) anti-leukemia activity is potentiated by Chk1 inhibition. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3479. doi:10.1158/1538-7445.AM2015-3479
Abstract 3482: Combination of bexarotene and the retinoid CD1530 reduces murine oral-cavity carcinogenesis induced by the carcinogen 4-nitroquinoline 1-oxide
Authors: Tang Xiao-Han , Gudas Lorraine J.
Published: August 2015

We investigated the effects of bexarotene (a retinoid X receptor agonist), CD1530 (a retinoic acid receptor γ selective agonist), and the combination of these two drugs for the prevention of oral carcinogenesis induced by the carcinogen 4-nitroquinoline 1-oxide (4-NQO) in a mouse model of human oral-cavity and esophageal squamous-cell carcinoma previously generated in our laboratory. We observed decreased numbers of neoplastic tongue lesions and reduced lesion severity in the 4-NQO plus CD1530 (4N+C) and 4-NQO plus bexarotene plus CD1530 (4N+B+C) groups compared with the 4-NQO group. RNA-Seq analyses showed increases in transcripts in cell proliferation/cell cycle progression pathways in the 4-NQO vs. the untreated group. In addition, β-catenin and matrix metallopeptidase 9 (MMP9) protein levels and reactive oxygen species (ROS), as assessed by 4-hydroxynonenal (4-HNE) staining, were elevated in tongue tissues 17 wk after the termination of the 4-NQO treatment. The 4N+B, 4N+C, and 4N+B+C groups showed dramatically lower levels of β-catenin, MMP9, and 4-HNE staining compared with the 4-NQO group. The major reduction in 4-HNE staining in the retinoid treatment groups suggests a novel mechanism of action, reduction of ROS, by which bexarotene and CD1530 inhibit carcinogenesis.

Citation Format: Xiao-Han Tang, Lorraine J. Gudas. Combination of bexarotene and the retinoid CD1530 reduces murine oral-cavity carcinogenesis induced by the carcinogen 4-nitroquinoline 1-oxide. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3482. doi:10.1158/1538-7445.AM2015-3482
Abstract 3487: A novel role of transient receptor potential vanilloid type 2 (TRPV2) for augmentation of chemotherapeutic drug efficacy in triple-negative breast cancer
Authors: Elbaz Mohamad M. , Nasser Mohd W. , Zhao Helong , Ganju Ramesh K.
Published: August 2015

Transient receptor potential vanilloid type 2 (TRPV2) is a non-selective cation channel that is triggered by agonists like cannabidiol (CBD). Chemotherapeutic drugs such as doxorubicin (DOX) and paclitaxel (PAC) are routinely used for treatment of Triple negative breast cancer (TNBC) patients however, these drugs are usually resisted and show limited efficacy and more side effects at higher doses. In the present study, we analyzed the ability of TRPV2 activation in enhancing the chemotherapeutic efficacy in TNBC cells. Interestingly, we found that TRPV2 is significantly up regulated in primary and metastatic breast tumor tissues compared to normal breast tissues using tissue microarray analysis. In addition, using publically available Kaplan Miere Plotter datasets, we found that estrogen receptor (ER) negative patients with higher TRPV2 expression levels and committed to anti-tumor chemotherapy have significantly higher survival than patients committed to anti-tumor chemotherapy but have lower TRPV2 expression levels. Our in vitro studies showed that TNBC cells subjected to combination treatment of CBD and DOX show enhanced proliferation inhibition compared to cells treated with DOX only . Analysis of molecular mechanisms showed higher levels of cleaved PARP and cleaved Caspase-3 in combination treatment compared to Dox alone. Further studies revealed that CBD activates more uptake of DOX into TNBC cells. This increased uptake was abrogated upon treatment with specific TRPV2 blocker. Furthermore, TRPV2 blocker inhibited the increased levels of cleaved PARP and cleaved caspase-3 in the combination treatment. By using two orthotopic mouse model, we showed that mice treated with CBD in combination with doxorubicin have significantly less tumor weight, fewer Ki67 and CD31 positive cells, and significantly higher level of cleaved caspase 3 and cleaved PARP compared to the mice treated with CBD or DOX alone. This study suggests the use of TRPV2 agonists as an adjuvant therapy to improve the anti-tumor chemotherapeutic efficacy especially in TNBC patients.

Citation Format: Mohamad M. Elbaz, Mohd W. Nasser, Helong Zhao, Ramesh K. Ganju. A novel role of transient receptor potential vanilloid type 2 (TRPV2) for augmentation of chemotherapeutic drug efficacy in triple-negative breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3487. doi:10.1158/1538-7445.AM2015-3487
Abstract 3490: Topotecan synergizes with CHEK1 inhibitor to induce apoptosis in ovarian cancer cells
Authors: Kim Marianne K. H. , James Jana , Annunziata Christina
Published: August 2015

Background

Topotecan is a therapeutic option for women with platinum-resistant or -refractory ovarian cancer. However, the dose-limiting toxicity of topotecan is myelosuppression. This led us to seek a combination treatment to augment topotecan anti-cancer activity in a cancer-targeted manner. Ovarian serous cancers, a major subtype, show dysregulated DNA repair pathway and often display a high level of CHEK1, a cell cycle regulator and DNA damage sensor. CHEK1 inhibitors are a novel approach to treatment, and have been used as single agents or in combination chemotherapy in many cancers.

Methods

We evaluated the cellular effects of topotecan in a panel of high grade serous (HGS) and non-HGS ovarian cancer cells. We then determined IC50s of topotecan in the absence and presence of suboptimal concentrations of CHEK1 inhibitor, PF477736. Synergism between topotecan and PF477736 was calculated based on cellular viability assays. Cytotoxic effect of the combined treatment was compared with apoptotic activities by Caspase3/7 activity assay and Western blotting of cleaved-PARP1 and γH2A.X.

Results

Non-HGS ovarian cancer cells were generally more sensitive to topotecan treatment compared to HGS ovarian cancer cells. When combined with suboptimal concentrations of CHEK1 inhibitor, topotecan potently and synergistically inhibited the proliferation of HGS ovarian cancer cells. This dramatic synergism in cellular toxicity was consistent with increases in markers of apoptosis.

Conclusions

Our findings suggest that the addition of CHEK1 inhibitor increases the response of ovarian cancer cells to topotecan. Furthermore, reduced dosages of both drugs achieved maximal cytotoxic effects by combining topotecan with CHEK1 inhibitor. This strategy would potentially minimize side effects of the drugs for extended clinical benefit.

Citation Format: Marianne K. H. Kim, Jana James, Christina Annunziata. Topotecan synergizes with CHEK1 inhibitor to induce apoptosis in ovarian cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3490. doi:10.1158/1538-7445.AM2015-3490
Abstract 3492: Metformin inhibits salivary gland tumor growth through cell cycle arrest and apoptosis
Authors: Guo Yuqi
Published: August 2015

Human salivary gland cancer (SGC) is one of the common malignancies found in the head and neck area. The limitation of the treatment and poor prognosis are calling for more investigations into novel intervention to improve the treatment modality in SGCs. Metformin as a widely used anti-type-2 diabetes medicine had demonstrated its anti-tumor potential in many different types of cancers. Our previous work demonstrated that metformin effectively targeted c-Myc oncogene to prevent the initiation and progression of prostate cancer. Interestingly, the overexpression of c-Myc has also been shown in some SGCs, such as salivary gland adenoid cystic carcinoma. Therefore, it is intriguing to explore metformin's anti-neoplastic efficacy of metformin in SGC. In this study, we used a human salivary adenocarcinoma cell line, HSY cell line as a model for salivary gland tumor. Our in vitro results show metformin prominently suppresses the growth of HSY cell through stimulation of cell cycle arrest and apoptosis. Meanwhile, metformin significantly down-regulates cMyc expression and rescues p53 tumor suppressor gene expression. Considering that mTOR inhibitors resistance could occur when tumors over-express cMYC. PP242, a novel and potent mTOR inhibitor was used in combination with metformin to inhibit HSY cell growth. As expected, metformin enhanced the inhibitory effects of PP242 associated with reduced c-MYC levels in vitro. Further in HSY xenograft tumors, massive necrotic areas were observed inside the tumors from metformin treated mice while only limited necrotic area in the core of tumors from PBS treated mice. Staining of proliferation marker Ki-67 confirmed lower proliferation rate in tumors from metformin treated group compare to that from the PBS group. In conclusion, our novel finding of metformin efficacy in SGC not only proves metformin plays a pivotal role in suppressing SGCs through cell cycle arrest and apoptosis, but also suggest that a combination treatment using metformin and mTOR inhibitors together may yield better inhibitory efficacy.

Citation Format: Yuqi Guo. Metformin inhibits salivary gland tumor growth through cell cycle arrest and apoptosis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3492. doi:10.1158/1538-7445.AM2015-3492
Abstract 3499: Improving therapeutic efficacy of Docetaxel in breast cancer
Authors: King Jeronay , Mir Hina , Kapur Neeraj , Singh Shailesh
Published: August 2015

Chemotherapy is the preferred choice for treatment of advance breast cancer (BrCa). In most cases, cytotoxic drugs are used at or near a maximum tolerated dose (MTD) to achieve maximum response and eradicate the neoplastic cells, at the same time MTD doses are often toxic and have severe side effects. Lower dose i.e. “optimal biological response modifier dose” (OBRMD) provides potentially beneficial responses, but is not capable of achieving optimal clinical response. Hence, the focus of this study was to achieve the optimal therapeutic outcome of Docetaxel (DTX) at a lower dose by using it in combination with Apigenin (API), a dietary flavonoid present in fruits and vegetables. Effect of DTX and API, either alone or in combination on BrCa cells viability and apoptosis was determined by MTT assay and flow cytometry, respectively. We further investigated the mechanism of enhanced efficacy of DTX using western blot analysis and real time qPCR. Significant decrease in cell viability was observed when cells were treated with low dose DTX in combination with API as compared to either of the agent used individually in MDA-MB-231, MDA-MB-468 and MCF 10A cells. Real time analysis showed that API up regulates pro-apoptotic molecules and down regulates anti-apoptotic molecules when using in combination with DTX. These findings suggest that Apigenin is capable of reducing the effective dose of docetaxel. Hence, this new modality may have better therapeutic outcome with minimal or no toxicity.

Citation Format: Jeronay King, Hina Mir, Neeraj Kapur, Shailesh Singh. Improving therapeutic efficacy of Docetaxel in breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3499. doi:10.1158/1538-7445.AM2015-3499
Abstract 3501: EGFR tyrosine kinase inhibitors combined with cytotoxic drugs for treatment of NSCLC with EGFR gene mutations: Efficacy and mechanisms
Authors: Yoshida Ryohei , Okumura Synsuke , Sasaki Takaaki , Ohsaki Yoshinobu
Published: August 2015

Background: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have improved overall survival in non-small-cell lung cancer (NSCLC) patients whose tumors have EGFR activating mutations. After treatment with EGFR-TKIs, NSCLC tumors with EGFR activating mutations become resistant to EGFR-TKIs, and development of novel treatment strategies is needed to improve survival in such patients.Next-generation EGFR-TKIs have been developed, and a clinical trial showed clinical activity of 3rd generation EGFR-TKIs in patients with acquired resistance, especially secondary mutation T790M to EGFR-TKIs. Moreover, clinical trials demonstrated survival benefit of combination with cytotoxic agents and EGFR-TKIs in patients with EGFR-mutated NSCLC. In contrast, the IMPRESS study showed that continuation of gefitinib in addition to cisplatin and pemetrexed didn't show survival benefit in patients with acquired resistance to gefitinib.Several basic studies reported that efficacy of targeted therapy combined with chemotherapy is schedule dependent. We, therefore, conducted an in vitro study to develop a novel therapeutic strategy for NSCLC with EGFR mutations. Methods: In vitro effects of docetaxel and an EGFR-TKI, gefitinib (AstraZeneca) or AZD9291 (Selleckchem), were examined in five lung cancer cell lines (PC9, PC9GR, HCC827, HCC827GR, and H1975) using a 3D culture model (PrimeSurface 96, SUMITOMO BAKELITE CO.). The NSCLC cells were treated with the combinationeither concurrently or sequentially (EGFR-TKIs after docetaxel or docetaxel after EGFR-TKIs). Combination Index (CI) values were calculated at various levels of cytotoxicity (the Chou-Talalay method). We evaluated changes in MAPK pathway activation and in expressions of Bcl2 family proteins and cleaved PARP (Cell Signaling) by western blot analysis. Results: Docetaxel followed by EGFR-TKIs weremore effective at CI, compared with EGFR-TKIs followed by docetaxel in two of the five cell lines with EGFR activating mutations, PC9GR (EGFR19del+T790M) and HCC827GR (EGFR19del+METamp) cells. The HCC827GR cells were likely to be more sensitive than PC9GR to the combination with docetaxel and gefitinib. The combo led to inactivation of the MAPK pathway and alteration of the Bcl2 family proteins. d) Conclusion: In conclusion, our results suggest that the sequential combination of docetaxel followed by EGFR-TKIs was effective against NSCLC with acquired resistance to EGFR-TKIs.

Citation Format: Ryohei Yoshida, Synsuke Okumura, Takaaki Sasaki, Yoshinobu Ohsaki. EGFR tyrosine kinase inhibitors combined with cytotoxic drugs for treatment of NSCLC with EGFR gene mutations: Efficacy and mechanisms. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3501. doi:10.1158/1538-7445.AM2015-3501
Abstract 3510: Novel lysine demethylase LSD1 inhibitors promote differentiation and apoptosis of glioma stem cells
Authors: Sareddy Gangadhara R. , Suzuki Takayoshi , Brenner Andrew J. , Vadlamdui Ratna K.
Published: August 2015

Glioblastoma (GBM) is the most common and devastating primary tumor of the central nervous system with dismal prognosis. GBM development is a multistep process, involving alterations in genetic and epigenetic mechanisms. Understanding the mechanisms and enzymes that promote epigenetic changes in GBM are urgently needed to identify novel therapeutic targets. Recent studies demonstrated that Glioma Stem Cells (GSCs) play central roles in GBM development and responsible for tumor propagation, invasion and chemo/radiation resistance. GSCs elimination is critical for development of efficient therapeutic strategies for GBM. Recently, we showed that lysine demethylase LSD1 is overexpressed in GBM and its inhibition reduces proliferation of GBM cells. In this study, we tested whether, LSD1 modulates GSCs differentiation and novel LSD1 inhibitors (NCL-1 and NCD-38) promote differentiation and apoptosis of GSCs. We have isolated GSCs using well established stem markers (CD133 and CD15) from two established and two patient derived GBM cells. Functionality of GSCs was established using self-renewal assays, and by profiling stem cell marker expression. Western analysis of purified GSCs showed that LSD1 is highly expressed in purified GSCs. Differentiation of GSCs resulted in decreased expression of LSD1. Down regulation of LSD1 expression using lentiviral LSD1-shRNA or by pharmacological inhibition (NCL-1 and NCD-38) significantly reduced the proliferation, neurosphere formation and self-renewal ability of GSCs with little or no effect on normal astrocytes and differentiated cells. Accordingly, treatment of GSCs with LSD1 inhibitors resulted in a dramatic reduction in the expression of stemness markers and promoted induction of differentiation markers. RNA sequencing analysis of GSCs treated with or without LSD1 inhibitors, revealed that LSD1 inhibitors modulate several pathways related to stem ness, differentiation and apoptosis. The expression of top five genes and three pathways were validated using q-RT-PCR, and western blot analysis. Chromatin Immunoprecipitation assays confirmed significant alternations in epigenetic markers at LSD1 target genes. Further, LSD1 inhibitors significantly reduced the growth of GSC driven tumors in vivo. Taken together, these results provided the evidence that induction of GSCs differentiation and apoptosis following LSD1 inhibition as a promising approach to eradicate GSCs.

Citation Format: Gangadhara R. Sareddy, Takayoshi Suzuki, Andrew J. Brenner, Ratna K. Vadlamdui. Novel lysine demethylase LSD1 inhibitors promote differentiation and apoptosis of glioma stem cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3510. doi:10.1158/1538-7445.AM2015-3510
Abstract 3514: A novel inhibitor of IDH1 abrogates 2-HG production and reverses aberrant epigenetic alterations in IDH1 mutant cells
Authors: Rominger Cynthia , Quinn Chad , Gao Enoch , Pietrak Beth , Rendina Alan , Smallwood Angela , Groy Arthur , Korenchuk Susan , McHugh Charles , Wiggall Ken , Reif Alexander , Schmidt Stanley , Qi Hongwei , Zhao Huizhen , Concha Nestor , Carpenter Christopher , Luengo Juan , Kruger Ryan , Schwartz Benjamin , Adams Nicholas , McCabe Michael T.
Published: August 2015

The isocitrate dehydrogenase 1 (IDH1) and IDH2 genes are mutated in acute myelogenous leukemia, low-grade glioma, intrahepatic cholangiocarcinoma, and chondrosarcomas. IDH1 and IDH2 normally function to convert isocitrate into alpha-ketoglutarate. However, when these enzymes are mutated at select residues the mutant enzymes now convert α-KG into 2-hydroxyglutarate (2-HG). In normal cells, 2-HG levels are typically extremely low, but IDH1/2 mutant cells can accumulate up to 10 mM 2-HG. In an effort to counteract the neomorphic activity of mutant IDH enzymes, we identified and developed potent inhibitors of IDH1. The compounds inhibit IDH1 catalytic activity in biochemical assays and reduce 2-HG production in IDH1-mutant cell lines. Consistent with the fact that 2-HG inhibits α-KG dependent enzymes including histone demethylases and Tet family hydroxylases, these IDH1 inhibitors induce a decrease in several histone methylation marks and also DNA methylation. These data demonstrate that small molecule inhibitors can reverse many of the epigenetic effects of mutant IDH1.

Note: This abstract was not presented at the meeting.

Citation Format: Cynthia Rominger, Chad Quinn, Enoch Gao, Beth Pietrak, Alan Rendina, Angela Smallwood, Arthur Groy, Susan Korenchuk, Charles McHugh, Ken Wiggall, Alexander Reif, Stanley Schmidt, Hongwei Qi, Huizhen Zhao, Nestor Concha, Christopher Carpenter, Juan Luengo, Ryan Kruger, Benjamin Schwartz, Nicholas Adams, Michael T. McCabe. A novel inhibitor of IDH1 abrogates 2-HG production and reverses aberrant epigenetic alterations in IDH1 mutant cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3514. doi:10.1158/1538-7445.AM2015-3514
Abstract 3517: Honokiol inhibits bladder tumor growth by suppressing EZH2/miR-143 axis
Authors: Yan Jun , Zhang Qing , Zhao Wei , Ye Changxiao , Chang Cunjie , Huang Xiaojing , Zhuang Junlong , Song Jiannan , Cui Yangyan , Eliaz Isaac , Shen Bing , Huang Ruimin , Ying Hao , Guo Hongqian
Published: August 2015

EZH2, a histone H3K27 methyltransferase, plays an essential role in regulation of cell proliferation, survival, invasiveness and cancer stem cell (CSC) maintenance. The upregulation of the histone methyltransferase EZH2 is frequently detected in various cancer types, including urinary bladder cancer (UBC). However, the mechanisms underlying its role in cancer cell are not yet fully understood. Honokiol, a biologically active biphenolic compound isolated from the Magnolia spp, has been linked with anticancer activities; however, its mechanisms is poorly understood. In this study, we investigated the in vitro and in vivo effects of honokiol on UBC cells and whether honokiol can modulate EZH2 mediated network. By employing MTT, colony formation, wound healing, transwell invasion, Western blot, and Aldofluor stem cell detection assays, honokiol was shown to inhibit human UBC cell proliferation, survival, CSC maintenance, migration and invasion. Immunoblotting assay showed that the reduction of EZH2 expression level by honokiol was correlated with the decreases of MMP9, CD44, Sox2, Notch1. Forced expression of EZH2 reversed honokiol induced cell growth arrest and low clonogenicity, indicating that EZH2 is a major downstream target for honokiol in UBC cells. Since EZH2 is essential for gene expression repression, we screened 24 cancer related miRNAs and found that tumor suppressor miR-143 was the most induced miRNA by honokiol treatment. Further quantitative RT-PCR, chromatin immunoprecipitation (ChIP) and functional analysis revealed that EZH2 directly inhibited the expression of miR-143, whereas the inhibition of miR-143 partially rescued the EZH2 knockdown-induced cell growth arrest and reduced clonogenicity. Moreover, in vivo investigation using xenograft analysis in athymic nude mice indicated that honokiol treatment inhibited tumor progression, which was associated with reduced EZH2, CD44, Sox2, Notch1 and MMP9, and increased expression of miR-143. Altogether, our data indicated that honokiol inhibited human UBC tumor growth and aggressiveness through suppression of EZH2 function and induction of its target, miR-143, and that honokiol is promising candidate for chemoprevention and/or therapeutic treatment for bladder cancer.

Citation Format: Jun Yan, Qing Zhang, Wei Zhao, Changxiao Ye, Cunjie Chang, Xiaojing Huang, Junlong Zhuang, Jiannan Song, Yangyan Cui, Isaac Eliaz, Bing Shen, Ruimin Huang, Hao Ying, Hongqian Guo. Honokiol inhibits bladder tumor growth by suppressing EZH2/miR-143 axis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3517. doi:10.1158/1538-7445.AM2015-3517
Abstract 3518: Growth inhibition of SCLC cell lines by treatment with LSD1 inhibitors is associated with modulation of neuroendocrine pathways
Authors: Paul Thomas A. , Sharma Shikhar , Hallin Jill , Xie Tao , Nichols Timothy , Greig Mike , Hardwick James , Wythes Martin , Verhelle Dominique
Published: August 2015

Small cell lung cancer (SCLC) is an aggressive malignancy with a high propensity for early metastasis. Response rates to first-line chemotherapy are typically high, but short lived. We describe an epigenetic-based mechanism for targeting SCLC using inhibitors for the LSD1 histone lysine demethylase. Mechanistically reversible and irreversible LSD1 inhibitors (GSK690 and OG-86) demonstrate induction of either cell cycle arrest or apoptosis in 54% of SCLC cell lines (12/22) that becomes apparent upon continuous treatment for 7-to-10 days. Maximal rates of growth inhibition in sensitive cell lines vary from 50-to-95% and plateaus between 18-to-21 days of LSD1 inhibitor treatment. Thus, heterogeneous sensitivity to LSD1 inhibitors exists between cell line models as well as within subpopulations of cells in the same cell line.

To understand the mechanisms underlying LSD1 inhibitor activity in SCLC we have performed RNA-seq and ChIP-seq experiments coupled with bioinformatic analysis of expression signatures in sensitive and resistant models. Our data indicate that although LSD1 is over-expressed in SCLC cell lines and patient samples relative to non-small cell lung cancers, high LSD1 expression does not predict sensitivity to LSD1 inhibitors. Pathway analysis demonstrates that LSD1 inhibition modulates the expression of genes involved in cell adhesion and axon guidance including members of the Ephrin and Semaphorins families. At LSD1 target genes, we demonstrate site-specific H3K4me2 histone methylation changes overlapping LSD1 binding sites, however no global changes in H3K4me2 were observed. Interestingly we find morphological and cell adhesion changes in sensitive cell lines that coincide with expression changes in markers of neuroendocrine differentiation of SCLC such as GRP, NCAM, and NEUROD1. Based on these data, we propose a model that LSD1 inhibition modulates the neuroendocrine differentiation program of SCLC cells promoting tumor inhibition in sensitive SCLC models.

Citation Format: Thomas A. Paul, Shikhar Sharma, Jill Hallin, Tao Xie, Timothy Nichols, Mike Greig, James Hardwick, Martin Wythes, Dominique Verhelle. Growth inhibition of SCLC cell lines by treatment with LSD1 inhibitors is associated with modulation of neuroendocrine pathways. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3518. doi:10.1158/1538-7445.AM2015-3518