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Gastric cancer (GC) is the fifth most frequent malignancy and the fourth leading cause of worldwide cancer-related death. Despite the usage of multimodal perioperative chemotherapy (pCT), GC progressively gains chemoresistance, thereby, the identification of suitable targets to overcome drug resistance is fundamental. Amongst the potential biomarkers, carbonic anhydrase IX (CAIX) - associated with a poor prognosis of several solid cancers - has gained the most attention. In a cohort of GC patients who received perioperative FLOT (i.e., Leucovorin, 5-Fluouracil, Docetaxel, and Oxaliplatin) or FOLFOX (i.e., Leucovorin, 5-Fluouracil, and Oxaliplatin), non-responder patients showed an increased expression of tumor CAIX compared to responder group. Moreover, GC cell lines induced to be resistant to 5-Fluouracil, Paclitaxel, Cisplatin, or the combination of 5-Fluorouracil, Oxaliplatin, and Docetaxel, overexpressed CAIX compared to the control. Accordingly, CAIX-high-expressing GC cells showed increased therapy resistance compared to low-expressing cells. Notably, SLC0111 significantly improved the therapy response of both wild-type and resistant GC cells. Overall, these data suggest a correlation between CAIX and GC drug resistance highlighting the potential of SLC-0111 in re-sensitizing GC cells to pCT., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Synthetic lethality is an innovative framework for discovering novel anticancer drug candidates. One example is the use of PARP inhibitors (PARPi) in oncology patients with BRCA mutations. Here, we exploit a new paradigm based on the possibility of triggering synthetic lethality using only small organic molecules (dubbed "fully small-molecule-induced synthetic lethality"). We exploited this paradigm to target pancreatic cancer, one of the major unmet needs in oncology. We discovered a dihydroquinolone pyrazoline-based molecule ( 35d ) that disrupts the RAD51-BRCA2 protein-protein interaction, thus mimicking the effect of BRCA2 mutation. 35d inhibits the homologous recombination in a human pancreatic adenocarcinoma cell line. In addition, it synergizes with olaparib (a PARPi) to trigger synthetic lethality. This strategy aims to widen the use of PARPi in BRCA -competent and olaparib-resistant cancers, making fully small-molecule-induced synthetic lethality an innovative approach toward unmet oncological needs.

BRCA1 mutant carcinomas are sensitive to PARP inhibitor (PARPi) therapy; however, resistance arises. BRCA1 BRCT domain mutant proteins do not fold correctly and are subject to proteasomal degradation, resulting in PARPi sensitivity. In this study, we show that cell lines and patient-derived tumors, with highly disruptive BRCT domain mutations, have readily detectable BRCA1 protein expression, and are able to proliferate in the presence of PARPi. Peptide analyses reveal that chemo-resistant cancers contain residues encoded by BRCA1 intron 15. Mechanistically, cancers with BRCT domain mutations harbor BRCA1 gene breakpoints within or adjacent to Alu elements in intron 15; producing partial gene duplications, inversions and translocations, and terminating transcription prior to the mutation-containing BRCT domain. BRCA1 BRCT domain-deficient protein isoforms avoid mutation-induced proteasomal degradation, support homology-dependent DNA repair, and promote PARPi resistance. Taken together, Alu-mediated BRCA1 gene rearrangements are responsible for generating hypomorphic proteins, and may represent a biomarker of PARPi resistance.

Purpose: The role of cholesterol biosynthesis in hedgehog pathway activity and progression of hedgehog pathway medulloblastoma (Hh-MB) were examined in vivo Statins, commonly used cholesterol-lowering agents, were utilized to validate cholesterol biosynthesis as a therapeutic target for Hh-MB. Experimental Design: Bioinformatic analysis was performed to evaluate the association between cholesterol biosynthesis with hedgehog group medulloblastoma in human biospecimens. Alterations in hedgehog signaling were evaluated in medulloblastoma cells after inhibition of cholesterol biosynthesis. The progression of endogenous medulloblastoma in mice was examined after genetic blockage of cholesterol biosynthesis in tumor cells. Statins alone, or in combination with vismodegib (an FDA-approved Smoothened antagonist), were utilized to inhibit medulloblastoma growth in vivo Results: Cholesterol biosynthesis was markedly enhanced in Hh-MB from both humans and mice. Inhibition of cholesterol biosynthesis dramatically decreased Hh pathway activity and reduced proliferation of medulloblastoma cells. Statins effectively inhibited medulloblastoma growth in vivo and functioned synergistically in combination with vismodegib. Conclusions: Cholesterol biosynthesis is required for Smoothened activity in the hedgehog pathway, and it is indispensable for the growth of Hh-MB. Targeting cholesterol biosynthesis represents a promising strategy for treatment of Hh-MB. Clin Cancer Res; 24(6); 1375-88. ©2018 AACR ., (©2018 American Association for Cancer Research.)

Newly designed triazolothiadiazines incorporating with structural motifs of nonsteroidal analgesic anti-inflammatory drugs were synthesized and screened for their bioactivity against epithelial cancer cells. Compounds with bioactivities less then ∼5μM (IC50) were further analyzed and showed to induce apoptotic cell death and SubG1 cell cycle arrest in liver cancer cells. Among this group, two compounds (1g and 1h) were then studied to identify the mechanism of action. These molecules triggered oxidative stress induced apoptosis through ASK-1 protein activation and Akt protein inhibition as demonstrated by downstream targets such as GSK3β, β-catenin and cyclin D1. QSAR and molecular docking models provide insight into the mechanism of inhibition and indicate the optimal direction of future synthetic efforts. Furthermore, molecular docking results were confirmed with in vitro COX bioactivity studies. This study demonstrates that the novel triazolothiadiazine derivatives are promising drug candidates for epithelial cancers, especially liver cancer., (Copyright © 2016. Published by Elsevier Ltd.)

Advanced renal cell carcinoma (RCC) is an invariably fatal cancer. Currently, small-molecule inhibitors that target cell growth, angiogenesis, or nutrient-sensing pathways represent the primary pharmacologic interventions for this disease, but these inhibitors only delay tumor progression and are not curative. The cytokine IFN-γ showed the potential to provide lasting remission in several phase I/II trials for advanced RCCs, but subsequent trials, including a multicenter phase III study using IFN-γ as a monotherapy for RCCs, were less promising. Notably, these trials were designed to exploit the indirect immunomodulatory effects of IFN-γ, whereas its direct antitumor properties--including its ability to trigger programmed cell death in tumors-remain mostly untapped. Here, we show that the proteasome inhibitor bortezomib (PS-341, Velcade) sensitizes otherwise resistant RCC cells to direct necrotic death by IFN-γ. Mechanistically, we show that bortezomib functions, at least in part, by inhibiting prosurvival NF-κB signaling. In the absence of this signal, IFN-γ triggers programmed necrosis (or "necroptosis") dependent on the kinase RIP1. When taken together with the observation that NF-κB signaling is elevated in RCCs, these results provide rationale for the combined use of IFN-γ and bortezomib in the treatment of metastatic RCCs.