Description: Purpose: Gossypol and its analogs, through their ability to bind to and inactivate BH3 domain-containing antiapoptotic proteins, have been shown to inhibit the growth of various human cancer cells in culture and xenograft models. Here, we evaluated the antitumor efficacy of a novel gossypol derivative and BH3 mimetic ch282-5 (2-aminoethanesulfonic acid sodium-gossypolone) in colon cancer models. Several innovative combination strategies were also explored and elaborated. Experimental Design: Ch282-5 was synthesized by modifying the active aldehyde groups and R groups of gossypol according to a computer-aided drug design program. The stability of ch282-5 was examined by high-performance liquid chromatography, and cytotoxic effects of ch282-5 on colon cancer cells were assessed by MTS assay. Activation of mitochondrial apoptotic pathway by ch282-5 was evidenced with a series of molecular biology techniques. In vivo antitumor activity of ch282-5 and its combination with chloroquine, rapamycin, oxaliplatin, and ABT-263 was also evaluated in colon cancer xenograft models and experimental liver metastasis models. Results: Ch282-5 showed antiproliferative and pro-cell death activity against colon cancer cells both in vitro and in vivo , and the response to the drug correlated with inhibition of antiapoptotic Bcl-2 proteins, induction of mitochondria-dependent apoptotic pathway, and disruption of mitophagy and mTOR pathway. Ch282-5 also suppressed liver metastasis produced by intrasplenic injection of colon cancer cells. Furthermore, ch282-5 could potentiate the effectiveness of oxaliplatin and rescue ABT-263 efficacy by downregulation of Mcl-1 and elevation of platelet number. Conclusions: These findings provide a rational basis for clinical investigation of this highly promising BH3 mimetic in colon cancer. Clin Cancer Res; 22(6); 1445–58. ©2015 AACR .

Description: Purpose: Long noncoding RNAs (lncRNAs) have emerged as important regulators in a variety of human diseases, including cancers. However, the overall biological roles and clinical significance of most lncRNAs in gastric carcinogenesis are not fully understood. We investigated the clinical significance, biological function, and mechanism of LINC01234 in gastric cancer. Experimental Design: First, we analyzed LINC01234 alterations in gastric cancerous and noncancerous tissues through an analysis of sequencing data obtained from The Cancer Genome Atlas. Next, we evaluated the effect of LINC01234 on the gastric cancer cell proliferation and apoptosis, and its regulation of miR-204-5p by acting as a competing endogenous RNA (ceRNA). The animal model was used to support the in vitro experimental findings. Results: We found that LINC01234 expression was significantly upregulated in gastric cancer tissues and was associated with larger tumor size, advanced TNM stage, lymph node metastasis, and shorter survival time. Furthermore, knockdown of LINC01234-induced apoptosis and growth arrest in vitro and inhibited tumorigenesis in mouse xenografts. Mechanistic investigations indicated that LINC01234 functioned as a ceRNA for miR-204-5p, thereby leading to the derepression of its endogenous target core-binding factor β (CBFB). Conclusions: LINC01234 is significantly overexpressed in gastric cancer, and LINC01234–miR-204-5p–CBFB axis plays a critical role in gastric cancer tumorigenesis. Our findings may provide a potential new target for gastric cancer diagnosis and therapy. Clin Cancer Res; 24(8); 2002–14. ©2018 AACR .

Description: Purpose: Development of chemoresistance, poor prognosis, and metastasis often renders the current treatments for colorectal cancer (CRC) ineffective. Whether ursolic acid, a component of numerous medicinal plants, either alone or in combination with capecitabine, can inhibit the growth and metastasis of human CRC was investigated. Experimental design: The effect of ursolic acid on proliferation of CRC cell lines was examined by mitochondrial dye uptake assay, apoptosis by esterase staining, NF-B activation by DNA-binding assay, and protein expression by Western blot. The effect of ursolic acid on the growth and chemosensitization was also examined in orthotopically implanted CRC in nude mice. Results: We found that ursolic acid inhibited the proliferation of different colon cancer cell lines. This is correlated with inhibition of constitutive NF-B activation and downregulation of cell survival (Bcl-xL, Bcl-2, cFLIP, and survivin), proliferative (cyclin D1), and metastatic (MMP-9, VEGF, and ICAM-1) proteins. When examined in an orthotopic nude mouse model, ursolic acid significantly inhibited tumor volume, ascites formation, and distant organ metastasis, and this effect was enhanced with capecitabine. Immunohistochemistry of tumor tissue indicated that ursolic acid downregulated biomarkers of proliferation (Ki-67) and microvessel density (CD31). This effect was accompanied by suppression of NF-B, STAT3, and β-catenin. In addition, ursolic acid suppressed EGF receptor (EGFR) and induced p53 and p21 expression. We also observed bioavailability of ursolic acid in the serum and tissue of animals. Conclusion: Overall, our results show that ursolic acid can inhibit the growth and metastasis of CRC and further enhance the therapeutic effects of capecitabine through the suppression of multiple biomarkers linked to inflammation, proliferation, invasion, angiogenesis, and metastasis. Clin Cancer Res; 18(18); 4942–53. ©2012 AACR .

Description: Purpose: We have previously demonstrated that ritonavir targeting of glycolysis is growth inhibitory and cytotoxic in a subset of multiple myeloma cells. In this study, our objective was to investigate the metabolic basis of resistance to ritonavir and to determine the utility of cotreatment with the mitochondrial complex I inhibitor metformin to target compensatory metabolism. Experimental Design: We determined combination indices for ritonavir and metformin, impact on myeloma cell lines, patient samples, and myeloma xenograft growth. Additional evaluation in breast, melanoma, and ovarian cancer cell lines was also performed. Signaling connected to suppression of the prosurvival BCL-2 family member MCL-1 was evaluated in multiple myeloma cell lines and tumor lysates. Reliance on oxidative metabolism was determined by evaluation of oxygen consumption, and dependence on glutamine was assessed by estimation of viability upon metabolite withdrawal in the context of specific metabolic perturbations. Results: Ritonavir-treated multiple myeloma cells exhibited increased reliance on glutamine metabolism. Ritonavir sensitized multiple myeloma cells to metformin, effectively eliciting cytotoxicity both in vitro and in an in vivo xenograft model of multiple myeloma and in breast, ovarian, and melanoma cancer cell lines. Ritonavir and metformin effectively suppressed AKT and mTORC1 phosphorylation and prosurvival BCL-2 family member MCL-1 expression in multiple myeloma cell lines in vitro and in vivo. Conclusions: FDA-approved ritonavir and metformin effectively target multiple myeloma cell metabolism to elicit cytotoxicity in multiple myeloma. Our studies warrant further investigation into repurposing ritonavir and metformin to target the metabolic plasticity of myeloma to more broadly target myeloma heterogeneity and prevent the reemergence of chemoresistant aggressive multiple myeloma. Clin Cancer Res; 21(5); 1161–71. ©2014 AACR .

Description: Purpose: Osteoclast-mediated bone resorption through src kinase releases growth factors, sustaining bone metastases. This trial determined the recommended phase II dose (RP2D) and clinical efficacy of the src kinase inhibitor dasatinib combined with zoledronic acid in bone predominant, HER2-negative breast cancer metastases. Experimental Design: A 3+3 lead in phase I design confirmed the RP2D allowing activation of the single-arm, phase II trial. Zoledronic acid was administered intravenously on day 1, and dasatinib was given orally once daily for 28 days each cycle as twice daily administration caused dose-limiting toxicity (DLT). Response was assessed every three cycles. N-telopeptide (NTx) was serially measured. Results: A total of 25 patients were enrolled. No DLTs were noted at the RP2D of dasatinib = 100 mg/d. Common adverse events were grade 1–2: rash (9/25, 36%), fatigue (9/25, 36%), pain (9/25, 36%), nausea (6/25, 20%). The objective response rate in bone was 5/22 (23%), all partial responses (PR). The clinical benefit rate [PRs + stable disease (SD) ≥ 6 months] in bone was 8/22 (36%). Median time to treatment failure was 2.70 months [95% confidence interval (CI), 1.84–5.72] in the general cohort, 3.65 months (95% CI, 1.97–7.33) in patients with hormone receptor (HR)-positive breast cancer and 0.70 months (95% CI, 0.30–NA) in those with HR-negative disease. Factors associated with response in bone included lower tumor grade, HR-positive status, and pretreatment high NTx levels. Conclusions: Combination therapy was well tolerated and produced responses in bone in patients with HR-positive tumors. Clin Cancer Res; 22(23); 5706–12. ©2016 AACR .