bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2529: Debio 1143 synergizes with taxanes, topoisomerase and bromodomain inhibitors to inhibit growth of lung adenocarcinoma
Authors: Langdon Casey G. , Wiedemann Norbert , Held Matthew A. , Platt James T. , Mamillapalli Ramanaiah , Iyidogan Pinar , Theodosakis Nicholas , Levy Frederic , Robichon Denis , Zanna Claudio , Vuagniaux Gregoire , Sorensen Mel , Wang Shaomeng , Bosenberg Marcus W. , Stern David F.
Published: August 2015

Efficient induction of cell death is essential for efficacy of cancer therapies, and may be enhanced in combination therapies that promote apoptosis. Small molecule mimetics of the pro-apoptotic protein SMAC antagonize Inhibitor of Apoptosis Proteins (IAPs). Debio 1143 is a potent oral SMAC mimetic currently assessed in clinical trials in combination with chemo- and radiotherapy in different cancer indications.

We have conducted a “one vs. many” drug combination screen in which Debio 1143 is combined pairwise with a panel of 128 candidate partner agents in order to identify drug combinations that inhibit growth of lung adenocarcinoma cells. Several synergistic Debio 1143 combinations were selected for further analysis. We confirmed that Debio 1143 synergistically inhibited growth in combination with taxanes paclitaxel and docetaxel, topoisomerase inhibitor SN-38, and the bromodomain inhibitor JQ1. The combination of Debio 1143 with any of these agents further inhibited clonogenic colony formation and induced apoptosis more than either agent alone. In two Debio 1143-sensitive cell lines Debio 1143 also induced formation of the cell-death inducing complex - the ripoptosome. Interestingly, while Debio 1143 broadly reduced protein levels of cIAP1 across cell lines, specifically the combination with JQ1 also reduced cIAP2 and XIAP levels and inhibited the canonical NF-κB pathway while inducing the non-canonical NF-κB pathway.

Overall, these data support utility of several combinations of Debio 1143 with other agents, especially bromodomain inhibitors, in lung adenocarcinoma and other cancers. Specifically, these findings indicate that the synergy between JQ1 and Debio 1143 may derive from JQ1 contributing on different levels to key mechanisms relevant for SMAC mimetic antitumor activity.

Citation Format: Casey G. Langdon, Norbert Wiedemann, Matthew A. Held, James T. Platt, Ramanaiah Mamillapalli, Pinar Iyidogan, Nicholas Theodosakis, Frederic Levy, Denis Robichon, Claudio Zanna, Gregoire Vuagniaux, Mel Sorensen, Shaomeng Wang, Marcus W. Bosenberg, David F. Stern. Debio 1143 synergizes with taxanes, topoisomerase and bromodomain inhibitors to inhibit growth of lung adenocarcinoma. [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 2529. doi:10.1158/1538-7445.AM2015-2529
Abstract 2530: Bcl-2 and Bcl-xL dual inhibitor, ABT-737, circumvents JNK mediated upregulation of anti-apoptotic molecules in cisplatin treated non-small cell lung cancer models
Authors: KIM Eun Young , Kim Arum , Chang Yoon Soo
Published: August 2015

Introduction; Non-small cell lung cancer (NSCLC), which does not have druggable driver oncogene, is treated with cytotoxic chemotherapy, but clinical outcome is suboptimal. Cisplatin is still one of the most commonly used drugs for the treatment of NSCLC, and, however, there are limitations of the therapeutic effect because of the multiple resistance mechanisms. In particular, elevated level of anti-apoptotic proteins (Bcl-2, Bcl-xL, Mcl-1) triggered by cisplatin-induced DNA damage response correlate with the drug resistance. In this study, we investigated synergic effects of combined treatment with cisplatin and dual inhibitor of Bcl-2/Bcl-xL, ABT-737, in NSCLC models.

Materials and Methods; H460 and A549 NSCLC cells, and LSL K-Ras G12D mouse model were used. Protein expression was evaluated by immunoblotting and cytotoxicity was measured by FACS followed by annexin-V and PI staining. LSL Kras G12D mouse were inhaled 5 × 107 PFU AdCre virus at 8 weeks after birth and, in 24 weeks after inhalation, were taken microCT, randomized into 4 groups, and then treated with ABT-737 (50mg/kg, i.p., daily) and/or cisplatin (5 mg/kg, i.p., weekly) for two weeks.

Results; There was a dose dependent phosphorylation of JNK, which is most prominent between 6 to 24hr after cisplatin treatment. Expression of anti-apoptotic molecules, Bcl-2, Bcl-w, Bcl-xL, and Mcl-1 were increased by cisplatin treatment in a dose and time dependent manner. JNK specific activator, anisomycin, increased mRNA level of anti-apoptotic molecules. ABT-737 displaced BCL-xL to the cytoplasm and aggregated Bak. Furthermore, ABT-737 released cytochrome C from mitochondria to the cytoplasm. ABT-737 itself showed cytotoxic effects and combination of ABT-737 potentiates cytotoxic effects of cisplatin with strong synergism. Combination of ABT-737 with cisplatin treatment induced significant tumor regression in 2 weeks in LSL K-ras G12D mouse model when compared those treated with single agents or vehicle.

Conclusion; Combination of ABT-737 with cisplatin showed synergistic cytotoxic effects and anti-tumor activities in NSCLC preclinical models. These findings suggest that clinical trials using combination with ABT-737 and cisplatin may be beneficial in advanced NSCLC patients.

Citation Format: Eun Young KIM, Arum Kim, Yoon Soo Chang. Bcl-2 and Bcl-xL dual inhibitor, ABT-737, circumvents JNK mediated upregulation of anti-apoptotic molecules in cisplatin treated non-small cell lung cancer 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 2530. doi:10.1158/1538-7445.AM2015-2530
Abstract 2534: Sequenced combinations of platinum drugs and phytochemicals towards overcoming drug resistance in ovarian cancer
Authors: Althurwi Safiah I. , Yu Jun Qing , Beale Philip , Chan Charles , Huq Fazlul
Published: August 2015

Background and aims

Resistance to platinum-based chemotherapy remains a major obstacle in the treatment against human ovarian cancer. In this study, binary combinations of platinum compounds: cisplatin, carboplatin and oxaliplatin with phytochemicals: artemisinin, thymoquinone, curcumin, lupeol and oleanolic acid have been applied to human ovarian cancer cell lines: A2780, A2780cisR, and A2780ZD0473R using three different sequences of administration (0/0h, 0/4h and 4/0h) where 0/0h means both the drugs added at the same time, 0/4h means platinum added first followed phytochemical 4 h later and 4/0h means the converse.

Methods

Cytotoxicity was determined based on MTT reduction MTT assay. Median effect analysis was done to characterize combined drug action and combination Index (CI) was used as a measure of synergism or antagonism whereas cellular accumulation of platinum, platinum to DNA binding levels and proteomic studies were done to provide insight into drug resistance and synergism from combined drug action.

Results

The combinations of platinum and the phytochemicals produced sequence- and concentration-dependent synergism in the ovarian tumour models. The degree of synergism was greater in the resistant cell lines than the parent cell line. It was found that combination with phytochemicals also increased intracellular accumulation of platinum and the level of platinum binding with DNA. Proteomic study identified a number of proteins believed to be associated with cisplatin resistance in ovarian cancer cells A2780 and A2780cisR. The expression of the proteins were either down- or up-regulated in A2780cisR cell line as compared to A2780 cell line but fully or partially restored after treatment with synergistic combinations.

Conclusion

The results of the study indicate that appropriately sequenced combinations of platinum drugs and phytochemicals can provide a means of overcoming drug resistance in ovarian cancer.

Citation Format: Safiah I. Althurwi, Jun Qing Yu,, Philip Beale, Charles Chan, Fazlul Huq. Sequenced combinations of platinum drugs and phytochemicals towards overcoming drug resistance in 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 2534. doi:10.1158/1538-7445.AM2015-2534
Abstract 2537: CDK4/6 inhibition synergizes with KRAS-MAPK pathway targeting in pancreatic cancer
Authors: Castellanos Jason A. , Nagathihalli Nagaraj , Van Saun Michael N. , Kasmai Cameron , Xiong Yanhua , Merchant Nipun
Published: August 2015

Introduction:

Pancreatic ductal adenocarcinoma (PDAC) is one of the most difficult human malignancies to treat due to its innate and acquired therapeutic resistance. Our hypothesis is that cyclin-dependent kinase 4 (CDK4) mediates therapeutic resistance to targeting of the KRAS-MAPK pathway in PDAC.

Experimental Procedure:

We characterized the expression of total and phosphorylated Retinoblastoma (Rb) and MEK protein levels in KRAS wild-type (BxPC3) and KRAS mutant (PANC1, MiaPaca2) human PDAC cell lines at baseline and with MEK and CDK4 inhibition alone or in combination. We then assessed the effects of combined therapy on cell-cycle progression and tumorigenicity (in vitro and in vivo). Finally, using the Ptf1a cre/+;LSL-Kras G12D/+;Tgfbr2 flox/flox (PKT) mouse model of PDAC, we assessed the in vivo overall tumor growth and survival after combined treatment with CDK4/6 and MEK inhibitors.

Results:

Rb functions as a tumor suppressor, and it is inactivated when phosphorylated by CDK4-Cyclin-D1. The CDK4/6 inhibitor (LEE011) effectively inhibits phosphorylation of Rb in cell lines regardless of KRAS mutational status. Combined inhibition of CDK4/6 and MEK (MEK162) decreased phosphorylation of RB and MAPK expression synergistically in the KRAS mutant cell lines, but not the KRAS wild-type BxPC3 cell line. Cell cycle progression was delayed effectively with MEK inhibition alone in the KRAS wild-type cell line, yet only combined CDK4/6 and MEK inhibition effectively delayed cell cycle progression in the KRAS mutant cell lines. Colony formation and invasion were also significantly decreased when Kras mutant cells were treated with combined CDK4/6 and MEK inhibition compared to all monotherapy and control groups. Finally, treatment of PKT mice resulted in a modest increase in OS with MEK inhibition alone, but mice receiving combined CDK4/6 and MEK inhibition exhibited a four-fold increase in OS.

Conclusions:

Combined inhibition of CDK4/6 and MEK results in significantly enhanced therapeutic efficacy and prolonged survival in the aggressive PKT mouse model of PDAC. This study suggests that concurrent inhibition of CDK4/6 and MEK may be an effective treatment for PDAC.

Citation Format: Jason A. Castellanos, Nagaraj Nagathihalli, Michael N. Van Saun, Cameron Kasmai, Yanhua Xiong, Nipun Merchant. CDK4/6 inhibition synergizes with KRAS-MAPK pathway targeting in 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 2537. doi:10.1158/1538-7445.AM2015-2537
Abstract 2538: The dietary isoflavone biochanin-A in combination with atorvastatin induces cell cycle arrest and apoptosis in human pancreatic cancer cells
Authors: Bhushan Alok , Selvakumar Ponniah , Tadinada Satya Murthy , Lai James C.K.
Published: August 2015

Pancreatic cancer is a devastating disease with a poor prognosis. The American Cancer Society's estimates for pancreatic cancer in the United States for 2014 are about 46,420 new cases of pancreatic cancer and about 39,590 deaths from pancreatic cancer. There remains a clear need for effective mechanism-based approaches that can achieve long-term improvements in the management pancreatic cancer. While natural products are well recognized as sources of drugs for various diseases including cancer, very few studies systematically explored the role of natural products for their potential preventive/therapeutic benefit in pancreatic cancer. Although several studies have examined the effect of flavonoids, there are no studies examining how biochanin-A or atorvastatin regulates pancreatic cancer cells. We investigated the cell proliferation studies in pancreatic cancer cell lines, AsPC-1 and MiaPaCa-2. Interestingly, we observed that by combination of treatment of Biochanin-A and atorvastatin significantly decreased the viability of AsPC-1 and MiaPaCa-2 cells. Several studies have been demonstrated the STAT3 play an important roll in the progression cancer pathogenesis in various cancers. We examined the STAT3 expression in pancreatic cell line, PANC-1 in biochanin-A or atorvastatin or in combination treatments and observed 95% decrease in the phosphorylation of STAT3 observed. Similarly the combination drug treatment employing biochanin A and atorvastatin decreased activation of Akt in AsPC-1 cell line. The decreased cell viability in AsPC-1 cell line involved increased induction of apoptosis with combination treatment and this evidence was further strengthened by increased PARP cleavage in combination treated cells. Further studies will delineate the mechanism of signaling arrested by the combination of drugs, Biochanin-A and atorvastatin in pancreatic cells with the possibility for uncovering improved therapeutic strategies to overcome the effectiveness to treat pancreatic cancer patients.

Citation Format: Alok Bhushan, Ponniah Selvakumar, Satya Murthy Tadinada, James C.K. Lai. The dietary isoflavone biochanin-A in combination with atorvastatin induces cell cycle arrest and apoptosis in human pancreatic 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 2538. doi:10.1158/1538-7445.AM2015-2538
Abstract 2540: A new mathematical model and software, to enable improved quantification and interpretation of combinatorial drug effects
Authors: Di Veroli Giovanni Y. , Jodrell Duncan I. , Richards Frances M. , Goldlust Ian
Published: August 2015

Drug combinations are used commonly to treat patients with cancer. Combination studies are conducted in vitro, to support advancement to in vivo and/or clinical research. In order to interpret in vitro data, mathematical models and numerical methods are used to quantify degrees of drug synergism. Several traditional approaches exist but they have been questioned with regard to how resulting synergy or antagonism levels should be interpreted. Our aim was to develop a robust method to analyse in vitro drug combination data, avoiding the issues related to traditional models and methods. To facilitate its implementation, software to enable rigorous and systematic assessment of combinations in vitro was also developed. We have derived a new mathematical model to identify synergy distributions based on drug combination dose response surfaces. Our new model and the classical Bliss, Loewe and HSA models were incorporated into the newly developed Combenefit software. Combenefit enables systematic quantification of high-throughput screening data, incorporating statistical assessment, metrics to describe synergy distributions and advanced graphical visualisation. Using multiple simulations of combination data with expected outcomes, our approach showed that it always provided appropriate evaluation while classical models failed to do so. We showed how our new model is in principle better aligned with in vivo requirements of identifying combinations which provide improvements compared to single agents. We then proceeded to analyse a large high-throughput combination screen. We first demonstrated that dataset assessment is strongly model-sensitive. We then demonstrated that our new model identified the best combinations in terms of dose response, thus confirming our simulated cases. Therefore, we have developed a new mathematical model that solves fundamental issues of model relevance that are encountered with classical models in the context of drug combinations. The newly developed Combenefit software enables easily performing rigorous and systematic quantification of in vitro combinations based on this novel approach. (Combenefit is freely available on our institutional website http://www.cruk.cam.ac.uk/combenefit). The resulting procedure is robust and better aligned with our perception of in vivo requirements.

Citation Format: Giovanni Y. Di Veroli, Duncan I. Jodrell, Frances M. Richards, Ian Goldlust. A new mathematical model and software, to enable improved quantification and interpretation of combinatorial drug effects. [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 2540. doi:10.1158/1538-7445.AM2015-2540
Abstract 2543: Akt and Myc cooperate to promote cell proliferation in Lck-Dlx5 T-cell lymphomas
Authors: Tan Yinfei , Sementino Eleonora , Testa Joseph
Published: August 2015

Constitutive activation of AKT is a frequent occurrence in the development of human T-cell acute lymphocytic leukemia/lymphoma (T-ALL), due largely to inactivation of PTEN. Up regulation of MYC is also commonly observed in T-ALL. We previously demonstrated that transgenic expression of a constitutively active form of Akt2 alone is sufficient to initiate T-cell lymphoma in mice, and that tumor formation typically requires up regulation of c-Myc or Dlx5 caused by specific chromosomal rearrangements. Here we report that transgenic overexpression of Dlx5 specifically in the mouse thymus can also drive T-cell lymphomagenesis. Tumors from these mice were characterized by loss of Pten expression and trisomy 15. Proliferation of these lymphoma cells was highly sensitive to the Akt pathway inhibitors BEZ235 and RAD001 as well as to the Myc inhibitor JQ1. Additionally, BEZ235 was found to cooperate with JQ1 to induce a more profound effect on cell cycle arrest and apoptosis. Moreover, BEZ235 potentiated vincristine-induced apoptosis when cells were treated with both drugs simultaneously, whereas pretreatment with BEZ235 antagonized the cell-killing effect of vincristine. These findings suggest that combination therapies with AKT and MYC inhibitors hold promise for the treatment of T-ALL in the clinic.

Citation Format: Yinfei Tan, Eleonora Sementino, Joseph Testa. Akt and Myc cooperate to promote cell proliferation in Lck-Dlx5 T-cell lymphomas. [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 2543. doi:10.1158/1538-7445.AM2015-2543
Abstract 2545: Effect of aldehydes in anthracycline cytotoxicity in S. cerevisiae
Authors: Miles Jana S. , Mazu Tryphon K. , Flores-Rozas Hernan
Published: August 2015

Anthracyclines constitute drugs of choice as single agents or in combination therapy in cancers that are refractory to other therapies, such as triple negative breast cancer, commonly observed in African-American women (AA) and is characterized for lacking biomarkers for targeted therapy, and for being aggressive and carrying bad prognoses. Anthracyclines effectiveness is dose-dependent, which increases the risk of side-effects and eventually the development of drug resistance. In S. cerevisiae, mutants of HOM6 display hypersensitivity to doxorubicin by inactivation of the homoserine dehydrogenase. We hypothesized that the L-aspartate-semialdehyde accumulating at this step, sensitizes the cells to anthracyclines. We confirmed this by inactivating HOM3, a prior step in the threonine biosynthesis pathway which prevents the accumulation of the L-aspartate-semialdehyde, rescuing the hom6 strain. To expand our knowledge of the relationship between aldehydes and anthracyclines, we sought to identify other aldehydes that can enhance the toxic effects of doxorubicin. We exposed S. cerevisiae to aldehydes (acetaldehyde, formaldehyde and glutaraldehyde) alone and combined with doxorubicin, cisplatin and menadione. Combination of formaldehyde (2 mM) and doxorubicin was most effective at reducing cell survival by between 31 to 39-fold (in wild type cells) relative to doxorubicin and formaldehyde alone. This effect was dose-dependent on doxorubicin. Co-treatment with formaldehyde and doxorubicin also showed increased toxicity in anthracycline-resistant strains siz1 and msh2. Combination of formaldehyde (2 mM) and menadione (60 mM) reduced cell survival by between 1- to 1.5-fold in wild type cells. Combination of acetaldehyde (2 mM) and menadione (60 mM) reduced cell survival by between 1.6- to 2.2-fold in wild type cells. Wild type cells treated with the combination of cisplatin (80 μM) and acetaldehyde (2 mM) or glutaraldehyde (2 mM) showed a reduced cell survival by between 0.4- to 3.12-fold with the combination of cisplatin and glutaraldehyde being the more cytotoxic of the two. Acetaldehyde, formaldehyde and glutaraldehyde show enhanced toxicity of wild type cells when combined with cytotoxic drugs. The potential use of a combination of aldehydes and cytotoxic drugs could potentially lead to applications intended to enhance anthracycline-based therapy.

Citation Format: Jana S. Miles, Tryphon K. Mazu, Hernan Flores-Rozas. Effect of aldehydes in anthracycline cytotoxicity in S. cerevisiae. [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 2545. doi:10.1158/1538-7445.AM2015-2545
Abstract 2547: PEGPH20 enhances chemotherapy in patient-derived and traditional cell-derived xenograft NSCLC models
Authors: Cowell Jessica A. , Li Xiaoming , Jiang Ping , Zimmerman Susan , Symons Rebecca , Shepard H. Michael , Maneval Daniel C. , Thompson Curtis B.
Published: August 2015

Hyaluronan (HA) accumulates in the tumor microenvironment (TME) of many solid tumors, including prostate, colon, breast, stomach, ovary, pancreas and lung, and HA accumulation is associated with tumor progression and a negative clinical outcome. Accordingly, the HA degrading enzyme pegylated recombinant human hyaluronidase PH20 (PEGPH20) was developed to allow systemic therapy and enable treatment of HA-high tumors. Preclinical studies have demonstrated that PEGPH20-mediated HA removal from HA-rich xenograft tumors in mice decreases tumor interstitial fluid pressure and water content; resulting in decompression of tumor vasculature, increased tumor perfusion and enhanced chemotherapeutic (CTX) activity. As non-small cell lung cancer (NSCLC) is the most common cancer worldwide and is characterized by high levels of HA (∼30%), we aimed to evaluate PEGPH20 enhancement of anti-tumor activity of NSCLC CTXs. Specifically, using both cell derived xenograft (CDX) models, peritibial H2170/HAS3 human NSCLC xenografts, and patient derived xenograft (PDX) models, we investigated CTX tumor growth inhibition (TGI)+/- PEGPH20. Nude mice were inoculated with either H2170/HAS3 cells adjacent to the tibial periosteum or patient derived tumor fragments of human NSCLCs implanted subcutaneously, and tumor growth was monitored via ultrasonography or caliper, respectively. When tumors reached ∼400 mm3, mice were staged into four groups: (1) vehicle; (2) PEGPH20, (3) CTX(s), or (4) PEGPH20 + CTX(s). PEGPH20 alone depleted tumor HA in both CDX and PDX models. In CDX studies, PEGPH20 increased tumor perfusion, reduced hypoxia and decreased HIF-1α expression (p<0.05). A summary table of the TGI data is shown below. The average TGI for PEGPH20 plus CTX(s) was superior to all CTX(s) alone, suggesting that enzymatic depletion of TME HA increases tumor sensitivity to NSCLC CTXs, likely due to increased CTX access into the TME. PEGPH20 clinical trials in NSCLC are currently in development.

Summary of TGIsGroup (n≥5/group)CDX%TGI w/ docetaxelCDX%TGI w/ nab-paclitaxel + carboplatinPDX%TGI w/ docetaxelPDX%TGI w/ gemcitabine + cisplatin(p-value vs. V)Vehicle (V)----PEGPH20 (P)28.5 (p<0.05)11.5 (p>0.05)44.4 (p<0.01)29.3 (p>0.05)CTX(s)19.8 (p>0.05)68.6 (p<0.0001)52.5 (p<0.001)38.4 (p>0.05)P + CTX56.1 (p<0.001)93.5 (p<0.0001)>100 (p<0.0001)76.6 (p<0.01)

Citation Format: Jessica A. Cowell, Xiaoming Li, Ping Jiang, Susan Zimmerman, Rebecca Symons, H. Michael Shepard, Daniel C. Maneval, Curtis B. Thompson. PEGPH20 enhances chemotherapy in patient-derived and traditional cell-derived xenograft NSCLC 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 2547. doi:10.1158/1538-7445.AM2015-2547
Abstract 2558: The mechanistic study on the effect of platinum-based chemotherapy efficacy imposed by EGFR-TKI regulated ERCC1 in non-small cell lung cancer (NSCLC)
Authors: Cheong Hio Teng , Hui Connie Wun Chun , Xu Fei , Mok Tony Shu Kam , Wong Chi Hang
Published: August 2015

Platinum-based chemotherapy is conventionally the first line treatment for EGFR wild type patients while EGFR-TKI is the standard for patients with mutation. Subgroup biomarker studies conducted in FASTACT-2 (Wu et al Lancet Oncology 2013) indicated that patients with positive ERCC1 attained longer overall survival and progression free survival under intercalated chemotherapy and EGFR-TKI, in comparison with solely chemotherapy. EGFR-TKI is postulated to down-regulate ERCC1 expression in EGFR wild type NSCLC cells, hence enhancing the Chemo efficacy. The study aims to investigate the missing link between EGFR and ERCC1 in the perspective of mechanistic means.

In vitro and in vivo studies were devised to examine the impact imposed on ERCC1 by EGFR-TKI. H1993 cells underwent a 72-hour EGFR-TKI treatment and transient siRNA transfection for ERCC1 suppression. Cell viability assay was employed for detecting the cisplatin sensitivity of the transfected cells. Xenograft tumor models were established with a 2-week treatment of oral erlotinib on animals, using western blot and IHC to study the ERCC1 expression. Human EGFR Phosphorylation Membrane Array was used to study the EGFR phosphorylation pattern involved in ERCC1 level alterations and its downstream pathways were further analyzed with western blot.

ERCC1 expression level is not correlated with EGFR-TKI sensitivity. Nonetheless, ERCC1 level gradually decreased along the 72-hour exposure of EGFR-TKI. The cells’ sensitivity towards cisplatin was raised upon ERCC1 knock-down with its IC50 reduced from 14.67μM to 0.16μM. Furthermore, TKI showed a significant reduction in ERCC1 level with IHC staining after treatment yet no sequel on the tumor volume of the xenografts. On the mechanistic side, 6 out of 17 EGFR phosphorylation sites were found compelling in respond to variations on ERCC1 level. We discovered that the MAPK/ERK and JNK pathways were the potential candidates that regulated EGFR associated ERCC1 expression.

In summary, the data manifested that EGFR-TKI may reduce ERCC1 expression and latently enhance sensitivity towards cisplatin. MAPK/ERK and JNK pathways may contribute in ERCC1 regulation. With the preliminary screening results, it warrants further investigation to validate the underlying mechanism for the regulation of ERCC1 expression level.

Citation Format: Hio Teng Cheong, Connie Wun Chun Hui, Fei Xu, Tony Shu Kam Mok, Chi Hang Wong. The mechanistic study on the effect of platinum-based chemotherapy efficacy imposed by EGFR-TKI regulated ERCC1 in non-small cell lung cancer (NSCLC). [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 2558. doi:10.1158/1538-7445.AM2015-2558
Abstract 2563: Modulation of DNA damage responses and cytotoxicity of bleomycin by vitamin C
Authors: Rubis Blazej , Zhitkovich Anatoly
Published: August 2015

Bleomycin (BL) is an iron-chelating chemical that is used for treatment of several types of cancer. The administration of this drug to patients is also associated with significant side effects, including life-threatening lung fibrosis. Biological factors affecting chemotherapeutic effectiveness of BL and the severity of its major side effects remain poorly understood. Cytotoxic effects of BL are attributed to its ability to cause DNA breaks via oxidative reactions by chelated iron. Ascorbate is a main cellular antioxidant, which can also promote redox cycling of iron by reducing its ferric form. Standard cultures of human cells contain less than 1% of physiological amounts of vitamin C, raising concerns whether common in vitro models adequately recapitulate major mechanistic aspects of BL toxicity in vivo. In this work, we investigated the effects of intracellular ascorbate on cell killing and DNA damage-activated stress responses by BL. We found that replenishment of human lung carcinoma cells with ascorbate increased cytotoxicity and clonogenic lethality of BL. Examination of DNA damage responses in BL-treated cells found that cellular ascorbate enhanced some signaling branches while suppressing others. Ascorbate-restored cells also displayed an increased dependence on nonhomologous end-joining DNA repair for their long-term survival. Overall, our results show that restoration of ascorbate levels increases sensitivity of cancer cells to killing by BL and alters their DNA damage responses. Low ascorbate levels in hypoxic tumors can contribute to their resistance to BL-based therapy.

Citation Format: Blazej Rubis, Anatoly Zhitkovich. Modulation of DNA damage responses and cytotoxicity of bleomycin by vitamin C. [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 2563. doi:10.1158/1538-7445.AM2015-2563
Abstract 2564: The anticancer molecule TPEN induces DNA damage in human colon cancer cells
Authors: Gali-Muhtasib Hala , Rahal Omar , Fatfat Maamoun , Hankache Carla , Osman Bassam , Khalife Hala , Machaca Khaled
Published: August 2015

The maintenance of optimal metal levels is an essential aspect of cell homoeostasis. However, in many types of cancer these metal levels especially iron, zinc and copper diverge from normal levels. We have recently shown that the zinc chelator TPEN increases the generation of reactive oxygen species (ROS) which selectively kills colon cancer cells. We have also provided evidence that the redox cycling of copper is responsible for TPEN anticancer effects. In this study, we aimed to further decipher the mechanism of TPEN-induced cell death in colon cancer cells through studying its effect on DNA damage. HCT116 p53+/+ human colon cancer cells were seeded were treated with 5μM TPEN at 50% confluence The inhibition of cell growth was measured by MTT, while ROS production was measured by the DCFH Assay using flow cytometry. siRNAs against DNApk and Chk2 was used to investigate the involvement of these DNA damage sensors in TPEN activity. DNA damage was assessed by the comet assay. Phosphorylation of ATM, ATR, Chk1, Chk2 and H2AX by TPEN were detected immunocytochemically by multiparameter cytometry. Expression levels of Chk1/2, ATR and DNApK were determined by western blotting. We show that cell death by TPEN is associated with significant DNA damage, an effect that was dependent on ROS generation and on the redox cycling of copper, as evidenced by reversal of DNA damage in the presence of antioxidants (NAC, CAT) or the copper chelator neocuproine (Neo). DNA damage was associated with increased expression of p-H2AX and a significant activation of ATM/ATR signaling molecules, specifically p-ATM, p-ATR and p-Chk1. Interestingly, silencing DNApk and Chk2 reversed DNA damage caused by TPEN, suggesting the involvement of DNApk and ATM/ATR pathways in TPEN-mediated effects. This study shows for the first time the involvement of DNApk and Chk2 in TPEN-induced DNA damage and confirms our previous findings that the redox cycling of copper is the main mechanism by which TPEN induces cell death in human colon cancer cells.

Citation Format: Hala Gali-Muhtasib, Omar Rahal, Maamoun Fatfat, Carla Hankache, Bassam Osman, Hala Khalife, Khaled Machaca. The anticancer molecule TPEN induces DNA damage in human colon 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 2564. doi:10.1158/1538-7445.AM2015-2564
Abstract 2574: HIPEC for treatment of peritoneal carcinomatosis: 40°C is the critical threshold temperature for potentiating chemotherapy efficacy in vitro and in vivo
Authors: Schaaf Lea , Münch Marina , Steurer Wolfgang , Aulitzky Walter E. , Mürdter Thomas E. , van der kuip Heiko , Ulmer Christoph
Published: August 2015

Hyperthermic intraperitoneal chemotherapy (HIPEC) combines circulated chemotherapy with enhanced temperature in the abdominal cavity of peritoneal carcinosis (PC) patients. Unfortunately, a standardized HIPEC protocol is missing hindering systematic comparisons with regard to minimal effective temperatures. The purpose of the present study was to systematically analyse the temperature needed for potentiation of chemotherapy effects in vitro. We then asked if this temperature could be sustained in patients during HIPEC and evaluated possible effects on survival. We therefore established a cell line-based model to mimic HIPEC conditions used in clinic. We evaluated intracellular drug concentrations and long-term survival using different temperatures ranging from 38 to 42°C combined with Cisplatin and Doxorubicin. In parallel we evaluated the temperature reached in the clinical setting by measuring inflow and outflow, as well as in the peritoneal cavity in 36 PC patients. Finally we determined the influence of different temperatures on survival. In vitro, we found temperature-dependent effects on intracellular drug concentration and long term survival only at temperatures above 40°C. In patients, during HIPEC, constant temperatures were reached after 10 minutes in the peritoneal cavity. A temperature above 40°C for at least 45 minutes was achieved in 67% or 44% of patients with HIPEC in open or closed abdomen, respectively. Importantly, we observed a significantly enhanced overall survival as well as a trend towards longer recurrent free survival in those patients with HIPEC temperatures above 40°C.

In conclusion, hyperthermia significantly potentiated the chemotherapy effects only at temperatures above 40°C in vitro. Importantly, this temperature threshold was also critical for overall and recurrent-free survival of PC patients.

Citation Format: Lea Schaaf, Marina Münch, Wolfgang Steurer, Walter E. Aulitzky, Thomas E. Mürdter, Heiko van der kuip, Christoph Ulmer. HIPEC for treatment of peritoneal carcinomatosis: 40°C is the critical threshold temperature for potentiating chemotherapy efficacy in vitro and in vivo. [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 2574. doi:10.1158/1538-7445.AM2015-2574
Abstract 2580: Screening of a mixture-based synthetic combinatorial library identifies small molecules that inhibit the ability of GTP to displace mant-GDP from mutant G12D KRas
Authors: Kennedy Perry C. , Guilanotti Marc C. , LsVoi Travis , Sebti Said M.
Published: August 2015

Although mutant KRas significantly contributes to human oncogenesis and patient tumor resistance to therapy, there are no anticancer drugs directly targeting mt KRas available in clinic. A major effort in our laboratory is to identify novel compounds that bind mt KRas and inhibit potently and selectively KRas-driven malignant transformation. To this end, we have used a mixture-based synthetic combinatorial library (scaffold ranking library) containing over 6 million compounds in a mant-GDP assay to identify chemical scaffolds that inhibit the ability of GTP to displace mant-GDP from mt G12D KRas. Subsequent screening of the positional scanning libraries derived from the hit mixtures led to several individual compound hits with the most potent inhibiting the ability of GTP to displace mant-GDP from mt G12D KRas with IC50 of 61 μM. Current studies are focused on physical characterization of the hits to mt KRas and cellular activities of these hits in mt KRas-dependent and -independent human cancer cell lines.

Citation Format: Perry C. Kennedy, Marc C. Guilanotti, Travis LsVoi, Said M. Sebti. Screening of a mixture-based synthetic combinatorial library identifies small molecules that inhibit the ability of GTP to displace mant-GDP from mutant G12D KRas. [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 2580. doi:10.1158/1538-7445.AM2015-2580
Abstract 2585: Discovery of a potent covalent mutant-selective EGFR inhibitor - the journey from high throughput screening to EGF816
Authors: Lelais Gerald , Epple Robert , Michellys Pierre-Yves , Marsilje Thomas H. , Long Yun , McNeill Matthew , Chen Bei , Lu Wenshuo , Bursulaya Badry , DiDonato Michael , Jia Yong , Kasibhatla Shailaja , Li Chun , Matushansky Igor , Bender Steven
Published: August 2015

Epidermal growth factor receptor (EGFR) is a validated therapeutic target for lung cancer. First and second generation EGFR inhibitors (e.g., gefitinib, erlotinib and afatinib) have revolutionized treatment paradigms of non-small cell lung cancer (NSCLC) patients with oncogenic EGFR mutations. The use of EGFR tyrosine kinase inhibitors (TKI) provides superior efficacy compared to chemotherapy in patients with EGFR L858R or exon 19 deletion tumors. However, resistance inevitably develops after 8-12 months of treatment; most commonly via a secondary T790M point mutation at the gatekeeper residue of EGFR. Furthermore, responses are hindered due to treatment intolerance in the form of rash and diarrhea that are mediated by simultaneous inhibition of wild-type (WT) EGFR at doses required for mutant EGFR suppression. To overcome these limitations, we initiated a project to identify mutant-selective EGFR inhibitors that potently inhibit both activating and T790M resistance EGFR mutations while sparing WT EGFR.

In this presentation, we report our medicinal chemistry approach and optimization that led to the discovery of EGF816, a selective and potent covalent mutant-selective EGFR inhibitor with single digit nanomolar cellular target modulation on both activating and T790M resistance mutations. In addition, we will also report validated clinical efficacy data from the first patient treated with EGF816.

Citation Format: Gerald Lelais, Robert Epple, Pierre-Yves Michellys, Thomas H. Marsilje, Yun Long, Matthew McNeill, Bei Chen, Wenshuo Lu, Badry Bursulaya, Michael DiDonato, Yong Jia, Shailaja Kasibhatla, Chun Li, Igor Matushansky, Steven Bender. Discovery of a potent covalent mutant-selective EGFR inhibitor - the journey from high throughput screening to EGF816. [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 2585. doi:10.1158/1538-7445.AM2015-2585
Abstract 2588: Anti-tumor effect of afatinib, an irreversible EGFR/HER2 dual inhibitor, in lung cancers harboring HER2 oncogene
Authors: Suzawa Ken , Toyooka Shinichi , Sakaguchi Masakiyo , Ohtsuka Tomoaki , Watanabe Mototsugu , Hashida Shinsuke , Maki Yuho , Yamamoto Hiromasa , Soh Junichi , Asano Hiroaki , Tsukuda Kazunori , Miyoshi Shinichiro
Published: August 2015

HER2 is a member of the EGFR family of tyrosine kinase receptors and plays important roles in the pathogenesis of certain human cancers. In non-small cell lung cancer (NSCLC), HER2 amplification or mutations are reported. However, little is known about the benefit of HER2-targeted therapy for NSCLC harboring HER2 alteration. In this study, we investigated the anti-tumor effect of afatinib, an irreversible EGFR/HER2 dual inhibitor, in lung cancers harboring HER2 oncogene alteration, including the novel HER2 mutations in transmembrane domain which we recently identified. Ectopically overexpressing HER2 wild-type or mutant (G776V,Cins, A775insYVMA, G660D, and V659E) in normal bronchial epithelial cells, BEAS2B, showed constitutive autophosphorylation of HER2 and activation of downstream signaling. They were sensitive to afatinib, but insensitive to EGFR-TKI (gefitinib). Furthermore, we examined anti-tumor activity of afatinib and gefitinib in several NSCLC cell lines, and investigated the association between their genetic alteration and sensitivity to afatinib treatment. Afatinib down-regulated the phosphorylation of HER2, EGFR, and their downstream signalings, and induced anti-proliferative effect through a G1 arrest and apoptotic cell death in HER2 altered cells (H2170, Calu-3, and H1781). Whereas, HER2 non-dependent NSCLC cells (A549, H1299, and H1993) were insensitive to afatinib. Our results strongly suggest that afatinib is a therapeutic option for NSCLC patients with HER2 alteration.

Citation Format: Ken Suzawa, Shinichi Toyooka, Masakiyo Sakaguchi, Tomoaki Ohtsuka, Mototsugu Watanabe, Shinsuke Hashida, Yuho Maki, Hiromasa Yamamoto, Junichi Soh, Hiroaki Asano, Kazunori Tsukuda, Shinichiro Miyoshi. Anti-tumor effect of afatinib, an irreversible EGFR/HER2 dual inhibitor, in lung cancers harboring HER2 oncogene. [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 2588. doi:10.1158/1538-7445.AM2015-2588
Abstract 2589: Investigations of covalent binding efficiency for third-generation EGFR irreversible inhibitors AZD9291 and CO-1686
Authors: Qin Zhen , Sun Xuebing , Liu Ye , Du Yunguang , Wang Miao , Hu Nan , Zhang Jiye , Peng Hao , Wang Lai , Wei Min , Luo Lusong
Published: August 2015

Patients with non-small cell lung cancer with activating EGFR mutations initially respond to first-generation and second-generation EGFR inhibitors. However, clinical efficacy is limited by acquired resistance, frequently driven by the EGFR T790M mutation. In addition, patients oftentimes experience severe side effects including rash and diarrhea due to the inhibition profile against wild-type EGFR. AZD9291 and CO-1686 are the leading third-generation irreversible EGFR inhibitors in clinical development. They selectively inhibit T790M EGFR, while sparing wild-type EGFR. In this study, we investigated the covalent binding efficiency of these two irreversible EGFR inhibitors using biochemical and cellular assays. We discovered that these two inhibitors had dramatic difference in covalent binding efficiencies in WT and mutant EGFR binding at biochemical and cellular levels. In pEGFR cellular assay, AZD9291 displayed much prolonged inhibition of pEGFR than CO-1686. In CO-1686 treated cells, recovery of pEGFR had reached 50% of control levels only after 4 hours. In the meantime, pEGFR in AZD9291 treated cells had no recovery even after 24 hours. These data may suggest different covalent bond formation efficiency and reversibility between different types of irreversible EGFR inhibitors. This may be one of the important factors for consideration when develop third-generation EGFR inhibitors.

Citation Format: Zhen Qin, Xuebing Sun, Ye Liu, Yunguang Du, Miao Wang, Nan Hu, Jiye Zhang, Hao Peng, Lai Wang, Min Wei, Lusong Luo. Investigations of covalent binding efficiency for third-generation EGFR irreversible inhibitors AZD9291 and CO-1686. [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 2589. doi:10.1158/1538-7445.AM2015-2589
Abstract 2592: Anti-tumor activity of icotinib (BPI-2009H) and BPI-403B in the BxPC-3 pancreatic cancer cell line
Authors: Wilde Victoria Lynn , Zhang Don , Peng Jirong , Green Michael A. , Greco Michael N. , Costanzo Michael
Published: August 2015

Introduction: The purpose of this research was to investigate the anti-tumor effect of BPI-2009H and BPI-403B, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) in the human pancreatic cancer cell lines BxPC-3 and Panc-1, in vitro and in vivo and determine the maximum tolerated dose (MTD) of the compound in mouse.

Experimental Design: In vitro, human pancreatic cancer cell lines, BxPC-3 and Panc-1 were exposed to varying concentrations of BPI-2009H and BPI-403B, the concentration of compound required to inhibit growth by fifty percent (IC50) was estimated. In vivo, tumor growth inhibition of low dose BPI-2009H was tested in xenografted nude mice with BxPC-3 pancreatic cancer tumors. The maximum tolerated dose (MTD) was established via oral administration of low, mid and high doses to Harlan mice of both BPI-2009H and BPI-403B. Upon determination of the MTD, the in vivo efficacy of high dose BPI-2009H was evaluated via tumor growth inhibition study on xenografted nude mice with BxPC-3 pancreatic cancer tumors.

Results: BPI-2009H, as a single agent, inhibited the growth of BxPC-3 cells in a dose dependent manner, with a relative IC50 value of 25.8 μM. BPI-403B, as a single agent, inhibited growth of BxPC-3 cells in a dose dependent manner as well, with a relative IC50 value of 2.7 μM. BPI-2009H and BPI-403B were tested up to 50μM in Panc-1 cells with no apparent effect at the upper limit of the study for either of the compounds. In vivo, the mice treated with BPI-403B demonstrated a statistically significant tumor growth delay, 14.3 days. 20% of the mice experienced tumor regression. The compound was well tolerated with minimal body weight loss. At low doses, BPI-2009H did not show any statistically significant tumor growth delay, but upon increasing the dose to the MTD, significant signs of anticancer activity was demonstrated, with an increase in tumor growth delay.

Conclusions: The in vitro and in vivo findings show that both BPI-2009H and BPI-403B have antiproliferative effects against BxPC-3 pancreatic cancer cells. These compounds are both well tolerated and may prove to be an alternative option of EGFR-TKI to erlotinib treatment in pancreatic cancer cases.

Citation Format: Victoria Lynn Wilde, Don Zhang, Jirong Peng, Michael A. Green, Michael N. Greco, Michael Costanzo. Anti-tumor activity of icotinib (BPI-2009H) and BPI-403B in the BxPC-3 pancreatic cancer cell line. [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 2592. doi:10.1158/1538-7445.AM2015-2592