bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5510: Tamoxifen induces estrogen receptor-independent bioenergetic stress: A synthetic lethality approach to target tumor metabolism
Authors: Daurio Natalie A. , Tuttle Stephen , Koumenis Constantinos
Published: August 2015

Tamoxifen, a selective estrogen receptor modulator (SERM) is clinically used for adjuvant treatment of estrogen receptor (ER) positive breast cancer. Recent data from our lab has shown that tamoxifen inhibits oxygen consumption at high, yet clinically relevant, doses. We hypothesize that this occurs through a non-ER dependent, direct effect on the mitochondria, and causes metabolic and signaling changes that can be exploited for therapeutic benefit. ER+, MCF7 breast cancer cells have a higher basal respiratory rate and lower glycolytic rate than ER, MDA231, cells. However, tamoxifen inhibited oxygen consumption to a similar degree in both cell lines Pharmacological inhibition of ERα expression or CRISPR-Cas9 mediated knock out of the ERα did not affect the ability of tamoxifen to decrease oxygen consumption. In response to tamoxifen inhibition of oxygen consumption, tumor cells increased dependence on glycolysis. Glucose deprivation or treatment with glycolytic inhibitors, 2-deoxy glucose (2DG) or 3-bromo-pyruvate significantly sensitized breast cancer cells to tamoxifen treatment. Tamoxifen combined with glucose deprivation or treatment with 2-DG led to robust activation of the AMPK signaling pathway. Knockout of AMPKα1 in breast cancer cells ameliorated cytotoxicity. Based on these data we’ve also demonstrated clinical usefulness of tamoxifen in a non-breast cancer model. BRAF inhibitor resistant melanoma exhibits a higher rate of oxidative phosphorylation over to the BRAF inhibitor sensitive melanoma cells. Tamoxifen-induced inhibition of oxygen consumption increased cytotoxicity in the OxPhos-addicted, BRAF inhibitor-resistant, population compared to the BRAF inhibitor sensitive cells. Our results indicate a new and unanticipated mechanism of action for tamoxifen in ER+ and ER-breast cancers. Moreover, since this effect is not ER dependent, tamoxifen may have clinical use in a wider spectrum of cancers especially when combined with inhibitors of glycolysis.

Citation Format: Natalie A. Daurio, Stephen Tuttle, Constantinos Koumenis. Tamoxifen induces estrogen receptor-independent bioenergetic stress: A synthetic lethality approach to target tumor metabolism. [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 5510. doi:10.1158/1538-7445.AM2015-5510
Abstract 5513: Employing a unique panel of breast cancer cellular lipids extracts in the development of a novel nanoliposome drug platform
Authors: Alharbi Hanan M. , Campbell Robert B.
Published: August 2015

Breast cancer is a major cause of cancer death in women worldwide. Breast cancer is a heterogeneous disease characterized by variant pathological features, disparate responses to therapeutics, and substantial differences in patient's long-term survival. The use of drug delivery systems such as liposomes can favorably alter the pharmacokinetic and biodistribution profile of commonly used drugs used to treat breast cancer disease.

An important feature of a drug delivery system is its ability to recognize and selectively target tumor cells with relatively high affinity when compared to healthy tissues. For this reason, the goal of this study was to develop a novel nanoliposome system that would target tumor cells to a significantly greater extent when compared to more conventional liposome systems. In this study, natural lipids extracted directly from breast cancer cells were used to prepare cellular lipid-extracted nanoliposomes (CLENs). The rationale is that an array of different lipids with a unique composition profile would represent a more relevant source of lipid material when compared to more traditional methods of liposome preparation. We therefore investigated whether the inclusion of extracted lipids derived from breast cancer cells would improve the selective uptake of liposomes by breast cancer cells, and related formulation features. To achieve these goals, three breast cancer cell lines were used (4T1, BT-20, and SK-BR-3), a normal breast fibroblast (CRL-2089), and an ovarian cancer cell line (SK-OV-3- used as a negative control).

The size of CLENs fell within the size range of 120- 203 nm and possessed a negatively-charged liposome surface charge potential (ranging between -10.97 and -20.97 mV). The nanoliposomes were also non-toxic to cells within the concentration range evaluated (up to 1μmol). Furthermore, without exception, the cellular uptake of CLENs was greatest when the extracted material used to prepare CLENs was the same as the target cell from which the lipids were extracted. In addition, when the breast cancer cell lines (4T1, SK-BR-3 and BT-20) were used to prepare CLENs, SK-OV-3 and CRL-2089 cell lines took up CLENs to a lesser extent, suggesting a more selective and differential cellular uptake.

In conclusion, the novel nanoliposome platform represents a promising drug delivery alternative to more conventional nano drug delivery systems. Additional formulation studies are currently underway.

Citation Format: Hanan M. Alharbi, Robert B. Campbell. Employing a unique panel of breast cancer cellular lipids extracts in the development of a novel nanoliposome drug platform. [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 5513. doi:10.1158/1538-7445.AM2015-5513
Abstract 5521: Interleukin-4 receptor-targeted liposomal doxorubicin for enhanced targeted drug delivery and antitumor effect in colorectal cancer
Authors: Yang Chih-Yung , Lin Chi-Hong , Jiang Jeng-Kai
Published: August 2015

Previously and our studies have observed that colorectal tumor has high interleukin-4 receptor α (IL-4Rα) expression, whereas adjacent normal tissue has low or no IL-4Rα expression. We use human atherosclerotic plaque-specific peptide-1 (AP1) that specifically target to IL-4Rα. This study investigated the in vitro binding and internalization of AP1, specific targeting to IL-4Rα, therapeutic efficacy and systemic toxicity in vivo of AP1-conjuagted liposomal doxorubicin. In vitro, The AP1 strongly bound to and was efficiently internalized into IL-4Rα-overexpressed CT26 cells than CT26 control cells, while little binding and internalizing of a control peptide was seen. Selective cytotoxicity experiment revealed AP1-conjugated liposomal doxorubicin preferentially killed the IL-4Rα-overexpressed CT26 cells compared to control CT26 cells. In addition, AP1-conjugated liposomal doxorubicin administered intravenously significantly inhibited tumor growth and decreased cardiotoxicity of doxorubicin in subcutaneously tumor-bearing mouse model. These results indicated that AP1-conjugated liposomal doxorubicin has a potent and selective anticancer potential against IL-4Rα-overexpressed colorectal cancers.

Citation Format: Chih-Yung Yang, Chi-Hong Lin, Jeng-Kai Jiang. Interleukin-4 receptor-targeted liposomal doxorubicin for enhanced targeted drug delivery and antitumor effect 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 5521. doi:10.1158/1538-7445.AM2015-5521
Abstract 5537: Nanoparticle delivery of an SN38 conjugate is more effective than Irinotecan in a mouse model of Neuroblastoma
Authors: Iyer Radhika , Croucher Jamie L. , Chorny Michael , Mangino Jennifer L. , Alferiev Ivan S. , Levy Robert J. , Kolla Venkatadri , Brodeur Garrett M.
Published: August 2015

Purpose: Neuroblastoma (NB) is the most common and deadly solid tumor in childhood. The majority of NB patients have advanced stage disease and a poor prognosis, so more effective, less toxic therapy is needed. We wanted to determine if more targeted delivery of chemotherapeutic agents would improve efficacy and reduce systemic toxicity. We developed a novel nanocarrier-based strategy for tumor-targeted delivery of a prodrug of SN38, the active metabolite of irinotecan.

Experimental Design: We formulated ultrasmall-sized (<100 nm) biodegradable poly(lactide)-poly(ethylene glycol) based nanoparticles (NPs) containing SN38 conjugated to tocopherol succinate (SN38-TS). We assessed alternative dosing schedules of SN38-TS NPs compared to irinotecan. An equivalent dose of SN38-TS NPs given 1x/2wk x 4 weeks (2 doses) had identical efficacy to irinotecan given 5x/wk x 4 weeks (20 doses), but none were cured. We then compared irinotecan 5x/wk x 8 weeks (40 doses) to SN38-TS NPs given 2x/wk x 4 weeks, 1x/wk x 8 weeks, and 2x/wk x 8 weeks (8, 8, and 16 doses, respectively).

Results: All SN38-TS NP regimens were far superior to irinotecan, and “cures” were obtained in all NP arms (no cures with irinotecan). SN38-TS NP delivery resulted in 200x the amount of SN38 in NB tumors at 4 hr post-treatment, and 25% of the 4-hr SN38 level remained at 72 hr post-treatment, compared to no SN38 detected at 24 hr post-treatment for the irinotecan arm; no toxicity was seen with NPs.

Conclusions: We conclude that this SN38-TS NP formulation improved delivery, retention, and efficacy, without causing systemic toxicity.

Citation Format: Radhika Iyer, Jamie L. Croucher, Michael Chorny, Jennifer L. Mangino, Ivan S. Alferiev, Robert J. Levy, Venkatadri Kolla, Garrett M. Brodeur. Nanoparticle delivery of an SN38 conjugate is more effective than Irinotecan in a mouse model of Neuroblastoma. [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 5537. doi:10.1158/1538-7445.AM2015-5537
Abstract 5538A: Cell size-specific intracellular delivery
Authors: Saung May Tun , Sharei Armon , Adalsteinsson Viktor , Liss Andrew , Cho Nahyun , Kamath Tushar , Ruiz Camilo , Kirkpatrick Jesse , Langer Robert , Love Christopher , Jensen Klavs
Published: August 2015

Among the many methods of intracellular delivery, cell size-selective delivery is particularly applicable to cancer research and therapeutics where tumor cells tend to be larger than blood cells and selective manipulation of a single cell-type while minimally affecting the other cells in a heterogeneous mixture is important. In this study, cell size-selective delivery is achieved using a novel microfluidic device with 75 parallel channels through which cells are pushed under nitrogen pressure. The cells undergo deformation as they transit through the channels, which results in temporary disruption of the cell membrane to facilitate delivery of material into the cytoplasm. For each cell size, there is a specific channel width for which optimal cell viability and fluorophore delivery is achieved, with smaller cells requiring narrower channels. When two cells of different sizes are mixed in solution, the channel width for optimal cell viability and fluorophore delivery for each cell type remains the same, and larger cells can achieve fluorophore delivery at a significantly higher percentage than smaller cells at the former's optimal channel width. One possible application for this technology is tagging circulating tumor cells, and we have been able to selectively deliver fluorophores into tumor cells when spiked into whole human blood with 91% specificity. We were also able to isolate pancreatic tumors cells from a patient's blood sample that matched the genotype of the patient's primary pancreatic tumor. Intracellular delivery of materials has become increasingly important as we delve deeper into understanding cellular processes and developing targeted therapies, and with this device, selective delivery can be achieved in a vector-free environment and without dependence on cell-surface receptors.

Citation Format: May Tun Saung, Armon Sharei, Viktor Adalsteinsson, Andrew Liss, Nahyun Cho, Tushar Kamath, Camilo Ruiz, Jesse Kirkpatrick, Robert Langer, Christopher Love, Klavs Jensen. Cell size-specific intracellular delivery. [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 5538A. doi:10.1158/1538-7445.AM2015-5538A
Abstract 5546: A natural alkaloid, berberine, as a novel transcriptional repressor of RET proto-oncogene in medullary thyroid carcinoma
Authors: Sun Daekyu , Kumarasamy Vishnu
Published: August 2015

The development of several medullary thyroid carcinomas is strongly associated with the gain-of-function mutation of the RET proto-oncogene, which encodes a receptor tyrosine kinase, so that the RET protein has been regarded as a potential therapeutic target for the treatment of progressive and advanced MTC. In our study we have explored a new strategy to repress the transcription of the RET proto-oncogene in MTC using small molecules. Interestingly, we found that a natural product berberine inhibits the RET gene transcription by specifically targeting the promoter region of this gene, thereby reducing the RET protein expression in MTC TT cells. The down-regulation of RET with berberine also results in the suppression of cell proliferation through cell cycle arrest and activation of apoptosis in TT cells. Overall, our results strongly suggest that berberine stabilizes G-quadruplexes formed from the G-rich sequence present on the promoter region of this gene and the stabilization of this structure play a critical role in mediating the repressive effect of berberine on RET transcription.

Citation Format: Daekyu Sun, Vishnu Kumarasamy. A natural alkaloid, berberine, as a novel transcriptional repressor of RET proto-oncogene in medullary thyroid carcinoma. [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 5546. doi:10.1158/1538-7445.AM2015-5546
Abstract 5549: Anti-proliferative effect of Oman's medicinal plants derived active principles on breast cancer cells (MDA MB 231)
Authors: Hakkim Lukmanul
Published: August 2015

Breast cancer (BC) is leading cause of death among females in United States and it is one of the emerging threats in Oman. Heavy doses of current clinical drugs are too toxic to patient and often failed to abort the recurrence after therapy. Despite huge number of reports on development of breast cancer chemotherapeutic drugs, median survival of BC patients not improved due to extreme ongoing and post treatment toxicity. Searching of drugs which can kill BC cells in a low dose by sparing normal cells is life time goal of many cancer researchers. Keeping the above fact in mind, we searched for potential natural products from Oman's medicinal plants which can kill BC cells potentially. We tested different doses (25, 50, 75 and 100 μg/ml) of sixty crude extracts and seventeen pure compounds obtained from Omani medicinal plants along with different dilutions (1:1000, 1:1500 and 1:2000 - prepared in medium) of Omani frankincense derived heavy oil for their ability to induce the cell death in MDA MB 231 cells with normal skin fibroblast as control. Doxorubicin used as positive drug control. After 24 hrs cells were checked for cell viability by MTT assay.

We set the criteria to select the potent anti-cancer active principle out of tested extracts and compounds that it should induce more than 50% cell death in ≤ 50 μg/ml drug concentration. As per this end point, fifteen extracts induced cell death in the range of 60%-90% and five pure compounds killed MDA MB 231 cells in the range of 75%-90%. Noticeably heavy oils can induce 90% cell death in very low dose (1:2000 dil.) of treatment by sparing normal skin fibroblast. Although it is primitive data, but this forms rationale for us to test this oil and other compounds and extracts in in vivo BC xenograft model and subsequently on BC heterogeneity, recurrence and metastasis.

Citation Format: Lukmanul Hakkim. Anti-proliferative effect of Oman's medicinal plants derived active principles on breast cancer cells (MDA MB 231). [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 5549. doi:10.1158/1538-7445.AM2015-5549
Abstract 5558: Growth inhibitory effect of perganum, sage, and olive leaves plant extracts on breast and lung cancer cell lines
Authors: Gibbs Carla , Almusallam Ola , Malone Trent E. , Myles Elbert L.
Published: August 2015

There are many different types of cancer, and generally each is defined by the type of cell that is affected. Cancer occurs in cells by which mutant genes are responsible for cell growth. This may result in metastasis which may affect one or more parts of the body. The current student attempts to address cancer treatment from Natural product sources. Sage leaves (Salvia officanlis), Perganum leaves (harmala), and Olive leaves (Olea europaea) were used in this study to determine their effects on two cancer cell lines, A549 and MCF-7. Our findings revealed that Salvia officanlis, Perganum harmala, and Olea europaea have significant effect on both cell lines (MCF-7 Brest cancer cell line and A549 lung cancer cell line). Salvia officanlis leaf extracts had a greater effect on MCF-7 and A549 than Perganum harmala and Olea europaea. Salvia Officanlis demonstrated a significantly decreased the growth rate and cell survival of both cancer cell lines at all concentrations. In future studies, Salvia officanlis, Perganum harmala, and Olea europaea act with MCF-7 Brest cancer cell line and A549 lung cancer cell line to inhibit their growth

Citation Format: Carla Gibbs, Ola Almusallam, Trent E. Malone, Elbert L. Myles. Growth inhibitory effect of perganum, sage, and olive leaves plant extracts on breast and lung cancer cell lines. [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 5558. doi:10.1158/1538-7445.AM2015-5558
Abstract 5560: Quercetin overcomes chemotherapy resistance in triple negative breast cancer
Authors: Srinivasan Asha , Thangavel Chellappagounder , Liu Yi , Shoyele Sunday , Den Robert B. , Selvakumar Ponniah , Lakshmikuttyamma Ashakumary
Published: August 2015

Triple negative breast cancer (TNBC) is one of the most aggressive breast cancers and is characterized by poor prognosis and high possibilities of tumor relapse. TNBC lacks specific receptors that are targets for breast cancer treatment options. Plant flavonoids have been identified to inhibit tumor growth and metastasis in various cancers. Our study revealed that quercetin, one of the major flavonoids present in fruits, vegetables, green tea, and red wine inhibit TNBC migration and invasion. Our data indicate that quercetin is able to induce the expression of E-cadherin and also down regulate vimentin levels in TNBC cells. Further the cellular localization of β-catenin is also altered by quercetin treatment. Also, studies identified that quercetin is capable of inhibiting the chemotherapy induced TGF-β signaling in TNBC cells, and that it would decrease the development of chemotherapy resistance in TNBC. Quercetin inhibits the TGF-β induced phosphorylation status of smad-2 in drug resistant cells. Further, quercetin is able to inhibit the enhanced migration and mammosphere formation of chemoresistant TNBC cells. Taken together, our findings revealed that quercetin is a promising natural product that increases the anti-cancer effect of chemotherapy drug in TNBC. Future studies in TNBC animal models are needed to confirm the therapeutic efficacy of quercetin in TNBC.

Citation Format: Asha Srinivasan, Chellappagounder Thangavel, Yi Liu, Sunday Shoyele, Robert B. Den, Ponniah Selvakumar, Ashakumary Lakshmikuttyamma. Quercetin overcomes chemotherapy resistance 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 5560. doi:10.1158/1538-7445.AM2015-5560
Abstract 5563: Tripterygium induces apoptosis in NSCLC via mitochondria dysfunction
Authors: Fan Xing-Xing , Li Na , Wu Jin-Lin , Zhou Yan-Ling , Liu Liang , He Jian-Xing , Leung Elaine L.
Published: August 2015

Lung cancer remains the leading cause of cancer deaths globally. Patients with non-small cell lung cancer (NSCLC) account for 80% of all lung cancer cases. Active mutation of EGFR was identified as one of the key anti-cancer target for NSCLC patients. Recently, tyrosine kinase inhibitor, like gefitinib which can specifically inhibit the activation of EGFR, emerges as a new potential anticancer drug. However, drug resistance remains an unsolved problem. Most of patient acquired resistance to this inhibitor within 12 months. Therefore, it is necessary and urgent to discover more effective potential agents as candidate drugs for treating gefitinib resistant NSCLC. Tripterygium, a triterpene extracted from the Chinese herb “Thunder of God Vine”, has been shown to have multiple bioactivities. Its anti-cancer effect has been proved in many kinds of cancers. However, the effect of Tripterygium on gefitinib-resistant NSCLC cells is still unknown. In this study, we examined the potency of Tripterygium in induction of apoptosis in a gefitinib-resistant NSCLC cell line and explored its underlying anti-cancer mechanism. Our results demonstrated that Tripterygium induced its apoptotic effect on NSCLC cells in a dose- and time-dependent manner. Moreover, the function of mitochondria was disrupted by the treatment of Tripterygium. The mitochondria membrane potential was gradually loss, and the ratio of Bax/Bcl-2 which is the indicator of mitochondria membrane integrity, was significantly up-regulated after the treatment of Tripterygium. Although the caspases were activated, the treatment of pan-caspase inhibitor could only partially inhibit the level of apoptosis. Moreover, the level of Hsp90 client proteins, EGFR and its downstream target AKT, were measured. Interestingly, both of them were remarkably decreased after Tripterygium treatment. Taken together, our data suggest that Tripterygium, which may be developed as a promising agent for gefitinib-resistant NSCLC patient, induced apoptosis through mitochondria dysfunction and EGFR degradation in gefitinib-resistant NSCLC cells.

Citation Format: Xing-Xing Fan, Na Li, Jin-Lin Wu, Yan-Ling Zhou, Liang Liu, Jian-Xing He, Elaine L. Leung. Tripterygium induces apoptosis in NSCLC via mitochondria dysfunction. [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 5563. doi:10.1158/1538-7445.AM2015-5563
Abstract 5587: Personalized risk prediction tool for esophageal adenocarcinoma in Caucasian population
Authors: Pu Xia , Ajani Jaffer A. , Gu Jian , Gu Xiangjun , Ye Yuanqing , Wu Xifeng
Published: August 2015

Backgrounds: Esophageal adenocarcinoma (EAC) is a deadly disease with the greatest increasing incidence rate among all cancers in the past few decades in the U.S. We aimed to develop a powerful risk prediction tool for EAC to assist in the prevention and early detection of this disease. Methods: A large case control study consisting of 924 EAC patients with 925 frequency-matched healthy controls was used to identify potential risk factors for EAC by univariate logistic regression. Stepwise logistic regression was used to select significant predictors in the final multivariate model. Discriminatory accuracy was measured by generating the receiver operator curve (ROC) and calculating the area under the curve (AUC). We also calculated the 5-year and 10-year absolute risk of developing EAC for hypothetical individuals with varying risk factor combinations. A simplified risk score (RS) was developed for easier risk communications and disseminations. Results: BMI, physical activity, smoking, family history, dietary intake, exposure to exhaust, Barrett's esophagus, hernia, esophageal ulcer, and GERD were included in the final model. The discriminative ability is excellent AUC of 0.884. Individuals with the highest RS have a 99% chance to be EAC cases compared to 1.4% for those with the lowest RS. Conclusions: We developed a comprehensive risk prediction model for EAC with excellent model performance. This model has the potential to be utilized in the clinic and public health settings to provide evidence-based risk mitigation strategy and identify high-risk population for targeted screening or prevention trials and for early detection of EAC.

Note: This abstract was not presented at the meeting.

Citation Format: Xia Pu, Jaffer A. Ajani, Jian Gu, Xiangjun Gu, Yuanqing Ye, Xifeng Wu. Personalized risk prediction tool for esophageal adenocarcinoma in Caucasian population. [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 5587. doi:10.1158/1538-7445.AM2015-5587
Abstract 591: Prognostic implications of PI3K mutation and amplification in curatively resected liposarcoma
Authors: Kim Joo Hoon , Kim Hyo Song , Lee Jae Seok , Kim Ki Hyang , Cho Yong Jin , Park Kyu Hyun , Kim Soo Hee , Ahn Joong Bae , Yang Woo Ik , Lee Young Han , Suh Jin-Suck , Shin Kyoo-Ho , Rha Sun Young
Published: August 2015

Background: We investigated the epidemiologic characteristics and prognostic significance of PIK3CA mutation/amplification in curative resected liposarcoma. Methods: A total of 125 liposarcoma tissue samples were collected over a 12-year period (2000-2012). PIK3CA mutation and amplification of gene copy number were analyzed by pyrosequencing method and fluorescence in situ hybridization (FISH).

Results: Nine of the 105 liposarcoma patients (8.6%) showed activating PIK3CA mutation.PIK3CA mutations were more frequent in myxoid/round cell and pleomorphic type vs well differentiated/dedifferentiated type (11.1% vs 88.9%, P = 0.044). In FISH analysis of PIK3CA, amplification of PIK3CA was detected in 31 of the 102 patients (30.4%) and histologic differences was not statistically significant in patients with PIK3CA amplification (48.4% vs 51.6%, p = 0.328). In survival analysis, PIK3CA amplified patients showed worse prognosis compared with PIK3CA-non amplified patients (median disease free survival (DFS) 119.2 vs 38.3 months p = 0.01). In multivariate analysis, positive PI3KCA amplification was an independent worse prognostic factor for DFS (p = 0.04; HR, 2.6; 95% CI 1.36 to 5.1). PIK3CA mutation was not associated with significant difference for DFS (p = 0.739)

Conclusion: We demonstrated that histologic differences according to PIK3CA mutation or amplification status. PIK3CA amplification was an independent worse prognostic factor for DFS. Further studies are needed to evaluate the potential diagnostic and therapeutic role of PIK3CA mutation and amplification in liposarcoma.

Citation Format: Joo Hoon Kim, Hyo Song Kim, Jae Seok Lee, Ki Hyang Kim, Yong Jin Cho, Kyu Hyun Park, Soo Hee Kim, Joong Bae Ahn, Woo Ik Yang, Young Han Lee, Jin-Suck Suh, Kyoo-Ho Shin, Sun Young Rha. Prognostic implications of PI3K mutation and amplification in curatively resected liposarcoma. [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 591. doi:10.1158/1538-7445.AM2015-591
Abstract 596: Differential cellular localization of Ephrin receptor tyrosine kinase B4 (EphB4) in melanoma progression
Authors: Chakravarti Nitin , Curry Jonathan L. , Bassett Roland L. , Prieto Victor G.
Published: August 2015

Background: Melanoma is an aggressive cancer with high metastatic potential, and is the most lethal skin malignancies. Ephrin receptor tyrosine kinase B4 (EphB4) modulates diverse physiologic and developmental processes, and may play an important role in melanoma tumorigenesis. In addition, Mertens-Walker et al., reported nuclear translocalization of EphB4 and hypothesized that it may directly regulate gene expression contributing to more aggressive biologic behavior in prostate cancer (Cancer Res 2011; 71 (8 Suppl): Abstract nr 1085). It is unknown whether differential cellular expression of EphB4 contributes to the pathogenesis of melanoma.

Methods: To explore the role of EphB4 in melanomagenesis, we have performed semiquantitative immunohistochemical analysis of EphB4 expression as measured by percentage and intensity of cells immunoreactive with anti-EphB4 in melanocytic nevi (n = 59), primary melanomas without metastasis during follow-up (n = 22), primary melanomas with metastasis (n = 17), and metastatic melanoma (n = 32).

Results: Melanocytic nevi had significantly higher nuclear EphB4 expression (p = 0.007) and lower cytoplasmic EphB4 expression (p = 0.002) when compared to all categories of melanoma. In fact we observed a dramatic decrease in nuclear EphB4 expression in metastatic melanoma compared to melanocytic nevi (p = 0.0009). In contrast, compared to melanocytic nevi, cytoplasmic expression for EphB4 were higher in primary melanoma (p = 0.005) as well as in melanoma metastases (p = 0.03). Although there was no significant difference in nuclear or cytoplasmic EphB4 expression between primary melanomas with or without metastasis, primary melanomas without metastasis showed significantly higher number of tumor cells having intense nuclear immunoreactivity for EphB4 protein than did metastatic melanomas (p = 0.006).

Conclusion: In conclusion, our data indicated that there is a gradual loss of nuclear EphB4 protein as well as increase in the levels of cytoplasmic expression of EphB4 protein associated with melanomagenesis. In addition, our results suggest a potential role for EphB4 as a therapeutic target in melanoma.

Citation Format: Nitin Chakravarti, Jonathan L. Curry, Roland L. Bassett, Victor G. Prieto. Differential cellular localization of Ephrin receptor tyrosine kinase B4 (EphB4) in melanoma progression. [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 596. doi:10.1158/1538-7445.AM2015-596
Abstract 601: Glycodelin expression in lung cancer and melanoma
Authors: Hautala Laura , Koistinen Hannu
Published: August 2015

Glycodelin (PAEP) is a lipocalin protein mainly expressed in well-differentiated epithelial cells in reproductive tissues. Previously, glycodelin has been shown to induce cell differentiation in endometrial and breast cancer cells. In breast cancer this was associated with reduced xenograft tumor growth. In ovarian and breast cancers glycodelin expression has been found to associate with a favorable prognosis as compared to glycodelin non-expressing tumors. Some preliminary studies suggest that glycodelin expression is increased also in lung cancer and melanoma. We studied the expression of glycodelin in these cancers using immunohistochemical staining of tissue arrays. Furthermore, the levels of mRNA were addressed utilizing in silico transcriptomics database (IST Online).

Glycodelin transcripts were more abundant in lung adenocarcinoma and melanoma as compared to non-malignant lung or squamous cell carcinoma of the lung and skin tissues, respectively. While immunohistochemical staining also showed increased staining of glycodelin in lung adenocarcinoma as compared to squamous cell carcinoma of the lung, there was no clear difference in staining as compared to normal lung tissue. Weak staining of glycodelin was observed both in normal skin and melanoma tissues. However, some melanoma cases showed very strong staining.

In conclusion, our data show that glycodelin is expressed both in melanoma and lung adenocarcinoma, and in some cases the expression is increased. However, the clinical relevance of these findings remains to be established.

Citation Format: Laura Hautala, Hannu Koistinen. Glycodelin expression in lung cancer and melanoma. [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 601. doi:10.1158/1538-7445.AM2015-601
Abstract 616: Blood-based molecular landscapes of resistance to EGFR blockade in colorectal cancer patients
Authors: Siravegna Giulia , Mussolin Benedetta , Buscarino Michela , Corti Giorgio , Cassingena Andrea , Crisafulli Giovanni , Corcoran Ryan B. , Ponzetti Agostino , Budillon Alfredo , Racca Patrizia , Marsoni Silvia , Di Nicolantonio Federica , Loupakis Fotios , Siena Salvatore , Sartore Bianchi Andrea , Bardelli Alberto
Published: August 2015

The molecular landscape of colorectal cancers (CRC) is presently assessed by genotyping neoplastic tissue obtained through surgical or bioptic procedures. We evaluated whether blood-based molecular profiles could be used to perform diagnostic determinations and monitor resistance to therapy in colorectal cancer patients. We find that RAS pathway mutations, which are commonly evaluated prior to administration of anti-EGFR antibodies, can be ascertained directly in the blood. Sequencing of circulating DNA identified genomic alterations in KRAS, NRAS, MET, ERBB2, FLT3, and MEK1 in patients with primary or acquired resistance to cetuximab or panitumumab. Secondary resistance to EGFR blockade is frequently accompanied by emergence of mutant RAS clones, which can be tracked in blood. We find that upon withdrawal of anti-EGFR antibodies, KRAS alleles decline in circulating DNA indicating that clonal evolution continues beyond clinical progression. Functional analysis of CRC cell populations, which had acquired resistance to cetuximab, revealed that KRAS mutant clones can decay when EGFR blockade is suspended. These results establish proof of principle that genotyping colorectal cancers using circulating DNA can inform therapeutic decisions, identify mechanisms of drug resistance and provide insights for further lines of therapy.

Citation Format: Giulia Siravegna, Benedetta Mussolin, Michela Buscarino, Giorgio Corti, Andrea Cassingena, Giovanni Crisafulli, Ryan B. Corcoran, Agostino Ponzetti, Alfredo Budillon, Patrizia Racca, Silvia Marsoni, Federica Di Nicolantonio, Fotios Loupakis, Salvatore Siena, Andrea Sartore Bianchi, Alberto Bardelli. Blood-based molecular landscapes of resistance to EGFR blockade in colorectal cancer patients. [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 616. doi:10.1158/1538-7445.AM2015-616
Abstract 620: Monitoring leptomeningeal metastasis treatment response using tumor cell free DNA from cerebral spinal fluid
Authors: Hayden Gephart Melanie
Published: August 2015

Background:

Cerebral Spinal Fluid (CSF) from brain tumor patients contains tumor cell free DNA (cfDNA), which may provide a non-invasive and routinely accessible method to obtain tumor genomic information. This “liquid biopsy” method would prove considerably less morbid compared to an open removal of tumor tissue from the brain. The opportunities of cfDNA in CSF have not been systematically studied in CSF, particularly in relation to how metastatic brain tumor cfDNA may respond to intrathecal therapy.

Methods:

A patient who presented with elevated intracranial pressure from metastatic melanoma to the leptomeninges underwent serial therapuetic lumbar punctures, approximately every two weeks over a period of three months. CSF was obtained through an informed consent, IRB approved protocol. The primary melanoma tumor was known to have a BRAF mutation 1799T>A (V600E). cfDNA was isolated from the CSF, and sequenced to confirm the presence of this same tumor-specific BRAF mutation. Droplet Digital PCR (ddPCR) quantified the mutant DNA amount and fraction in CSF. These results were compared to the clinical cytology results from the same sample.

Results:

Six time points were collected in 61 days. Tumor cfDNA was detectable in the first five time points. Mutant DNA fraction decreased from 53% to almost zero. The total amount of mutant DNA decreased from 220 copies per ml of CSF to 4 copies per ml of CSF. This result was concordant with the patient's clinical response to therapy.

Conclusion:

Tumor cfDNA was found in CSF from a cancer patient with leptomeningeal metastases. Both the mutant fraction and total copies of mutant DNA corresponded with the patient's response to systemic therapy. This non-invasive method may provide a powerful tool for identifying and monitoring the genetic fingerprint of brain metastases.

Citation Format: Melanie Hayden Gephart. Monitoring leptomeningeal metastasis treatment response using tumor cell free DNA from cerebral spinal fluid. [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 620. doi:10.1158/1538-7445.AM2015-620
Abstract 621: Serum circulating DNA and nucleosomes increase in response to neoadjuvant chemoradiation and surgical resection for pancreatic cancer
Authors: Naqvi Ibtehaj A. , Gunaratne Ruwan , Pisetsky David , White Rebekah
Published: August 2015

Introduction: Pancreatic cancer (PC) is the deadliest of the major cancers, and response rates to standard therapies are low. Tumor cells release circulating extracellular DNA (exDNA) and nucleosomes (short segments of DNA in complex with histone proteins). These factors have been evaluated as markers of disease burden for prognosis and response to therapy. We hypothesized that exDNA and nucleosome (NUC) levels would correlate with each other and decrease in patients (pts) undergoing neoadjuvant chemoradiation (CRT) and surgical resection for localized PC.

Methods: Blood was collected from pts with radiographically localized PC before and 4-6 weeks after CRT (N = 8), intraop and 1 week postop in pts with resectable tumors (N = 4), as well as from pts with advanced disease (N = 3) and normal volunteers (N = 6) to create a spectrum of data for disease burden. ExDNA and NUC were isolated from serum samples and quantified using a fluorescent DNA-specific stain (Picogreen) and ELISA, respectively.

Results: Normal volunteers had the lowest exDNA/NUC levels while patients with advanced disease had the highest levels. Overall, exDNA/NUC levels increased ∼3-fold in patients who underwent CRT to levels similar to those of patients with advanced disease, regardless of whether they had radiographic partial response (N = 4), stable disease (N = 4), or progressive disease (N = 2) on restaging nor whether they were subsequently able to undergo resection. ExDNA and NUC levels correlated well except in pts who underwent resection, when exDNA but not NUC levels peaked intraop at >5-fold post-CRT levels. Both exDNA and NUC levels remained elevated at least one week postop.

Discussion: Contrary to our hypothesis, exDNA and NUC levels increased following neoadjuvant CRT regardless of radiographic response to therapy. ExDNA and NUC levels correlated well except during the intraop period, when exDNA but not NUC levels were dramatically elevated. These data suggest that exDNA and NUC are not simply markers of disease burden. We postulate that exDNA and NUC are released by tumor cells and also by host immune cells in response to CRT and surgical trauma. In order to put this into a broader context, we are expanding our dataset to include more patients and time points. We are evaluating other specific forms of exDNA as well as DNA-associated proteins as markers of cell death that may be more useful for monitoring response to therapy.

Citation Format: Ibtehaj A. Naqvi, Ruwan Gunaratne, David Pisetsky, Rebekah White. Serum circulating DNA and nucleosomes increase in response to neoadjuvant chemoradiation and surgical resection for pancreatic 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 621. doi:10.1158/1538-7445.AM2015-621
Abstract 634: Novel antibody-drug conjugates targeting Axl show anti-tumor activity in solid cancer xenograft models
Authors: Breij Esther C.W. , Verploegen Sandra , Lingnau Andreas , van den Brink Edward N. , Janmaat Maarten , Houtkamp Mischa , Bleeker Wim K. , Satijn David , Parren Paul W.H.I.
Published: August 2015

Axl is a receptor tyrosine kinase of the TAM family, which is structurally characterized by the presence of two extracellular immunoglobulin-like domains and two fibronectin type III domains, a single-pass transmembrane region and an intracellular tyrosine kinase domain. Axl is aberrantly expressed and activated in both solid and hematological malignancies and has been associated with poor clinical prognosis in a number of cancers, including non-small cell lung cancer, breast cancer, pancreatic cancer and acute myeloid lymphoma. Functionally, Axl has been implicated in multiple pathological processes, such as tumor cell motility, adherence and migration, epithelial-to-mesenchymal transition, metastasis, angiogenesis and resistance to tyrosine kinase inhibitors.

With the aim to target Axl expressing cancers, a panel of Axl-specific antibody-drug conjugates (ADC) was generated. First, high affinity human Axl antibodies were generated in HuMAb mice. Binding studies using Axl mutants, in which specific human Axl domains had been replaced with their murine analogs, demonstrated that the Axl antibody panel consisted of antibodies against different Axl extracellular domains. Second, the Axl antibodies were conjugated with the microtubule disrupting agent monomethyl auristatin E (MMAE) using the protease cleavable valine citrulline linker.

Axl ADCs showed cytotoxic activity in vitro, which was dependent on target expression and on conjugation with cytotoxic payload. The anti-tumor activity of Axl ADCs was confirmed in vivo. Axl ADCs induced tumor regression in cell line derived xenograft models for lung cancer and epidermoid carcinoma. Anti-tumor activity was especially efficient in the lung cancer xenograft model, in which inhibition of tumor growth was observed upon treatment with a single dose of 0.5 mg/kg Axl ADC. In the same model, 1 mg/kg Axl ADC was sufficient to induce complete tumor regression. Importantly, Axl ADCs also showed efficient anti-tumor activity in patient-derived xenograft (PDX) models that showed heterogeneous target expression.

In summary, Axl is a novel target for antibody-mediated delivery of cytotoxic agents into tumor cells. The promising results obtained in preclinical tumor models support further development of Axl-specific ADCs.

Citation Format: Esther C.W. Breij, Sandra Verploegen, Andreas Lingnau, Edward N. van den Brink, Maarten Janmaat, Mischa Houtkamp, Wim K. Bleeker, David Satijn, Paul W.H.I. Parren. Novel antibody-drug conjugates targeting Axl show anti-tumor activity in solid cancer xenograft models. [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 634. doi:10.1158/1538-7445.AM2015-634
Abstract 639: Site specific conjugation of ARX-788, an antibody drug conjugate (ADC) targeting HER2, generates a potent and stable targeted therapeutic for multiple cancers
Authors: Humphreys Robin C. , Kirtely Jessica , Hewit Amha , Biroc Sandra , Knudsen Nick , Skidmore Lillian , Wahl Alan
Published: August 2015

Creation of ADCs by conjugating drug linkers and toxin payloads to available native lysines or cysteines generates ADCs with highly variable drug to antibody loading and linker stability profiles. Variable drug loading, amino acid position, conjugation chemistry and linker design affect the pharmacokinetic characteristics, potency and toxicity of the ADC. We describe here the synthesis and pharmacology of an ADC comprising a site-specifically conjugated dolastatin analog to an antibody targeting the EGF family receptor, HER2. To specify the site of conjugation and drug loading, a non-natural amino acid, para acetyl phenylalanine (pAcF), was incorporated at defined sites within the antibody primary sequence. This non-natural amino acid provides a linkable platform for covalent conjugation of a diverse array of payloads through a stable oxime bond. The dolastatin analog, MMAF, was coupled via a non-cleavable linker to the HER2 antibody at two specific sites to generate the ADC; ARX-788. In vitro cytotoxicity assays of ARX-788 generated picomolar IC50's across a spectrum of HER2 + cell lines from breast, ovarian, lung and gastric cancer. Multiple in vivo murine xenograft studies demonstrated a potent increase in anti-tumor activity when compared to T-DM1. A single injection of ARX-788 in established xenograft models of HER2 positive ovarian, gastric and breast cancer cell lines (SKOV3, BT474, N-87, and HCC1954) induced rapid regression in all models. ARX-788 induced regression in a Herceptin-resistant derived breast xenograft (JIMT-1) and was significantly more effective than T-DM1 at equivalent doses. Pharmacokinetic evaluation of ARX-788 in rodent and non-human primates (NHP) revealed long term stability of 12 and 8 days respectively. Importantly, the conjugated form of ARX-788 remained intact over the course of the 3 week study in NHP. Precise payload stability and effective half-life of ARX-788 due to site-specific conjugation provides an improved therapeutic window for this HER2-targeting ADC. ARX-788 is currently completing non-human safety and PK studies in anticipation of clinical trial evaluation in 2015.

Citation Format: Robin C. Humphreys, Jessica Kirtely, Amha Hewit, Sandra Biroc, Nick Knudsen, Lillian Skidmore, Alan Wahl. Site specific conjugation of ARX-788, an antibody drug conjugate (ADC) targeting HER2, generates a potent and stable targeted therapeutic for multiple cancers. [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 639. doi:10.1158/1538-7445.AM2015-639