Molecular Cancer Therapeutics最新文献

KRAS is the most frequently dysregulated oncogene with a high prevalence in non-small cell lung cancer, colorectal cancer, and pancreatic cancer. FDA-approved sotorasib and adagrasib provide breakthrough therapies for patients with cancer with KRASG12C mutation. However, there is still high unmet medical need for new agents targeting broader KRAS-driven tumors. An emerging and promising opportunity is to develop a pan KRAS inhibitor by suppressing the upstream protein of Son of Sevenless 1 (SOS1). SOS1 is a key activator of KRAS and facilitates the conversion of GDP-bound KRAS state to GTP-bound KRAS state. Binding to its catalytic domain, small-molecule SOS1 inhibitor has demonstrated the ability to suppress KRAS activation and cancer cell proliferation. RGT-018, a potent and selective SOS1 inhibitor, was identified with optimal drug-like properties. In vitro, RGT-018 blocked the interaction of KRAS:SOS1 with single-digit nanomoles per liter potency and was highly selective against SOS2. RGT-018 inhibited KRAS signaling and the proliferation of a broad spectrum of KRAS-driven cancer cells as a single agent in vitro. Further enhanced antiproliferation activity was observed when RGT-018 was combined with MEK, KRASG12C, EGFR, or CDK4/6 inhibitors. Oral administration of RGT-018 inhibited tumor growth and suppressed KRAS signaling in tumor xenografts in vivo. Combinations with MEK or KRASG12C inhibitors led to significant tumor regression. Furthermore, RGT-018 overcame the resistance to the approved KRASG12C inhibitors caused by clinically acquired KRAS mutations either as a single agent or in combination. RGT-018 displayed promising pharmacological properties for combination with targeted agents to treat a broader KRAS-driven patient population.

As tumor-associated macrophages (TAM) exercise a plethora of protumor and immune evasive functions, novel strategies targeting TAMs to inhibit tumor progression have emerged within the current arena of cancer immunotherapy. Activation of the mannose receptor 1 (CD206) is a recent approach that recognizes immunosuppressive CD206high M2-like TAMs as a drug target. Ligation of CD206 both induces reprogramming of CD206high TAMs toward a proinflammatory phenotype and selectively triggers apoptosis in these cells. CD206-activating therapeutics are currently limited to the linear, 10mer peptide RP-182, 1, which is not a drug candidate. In this study, we sought to identify a better suitable candidate for future clinical development by synthesizing and evaluating a series of RP-182 analogs. Surprisingly, fatty acid derivative 1a [RP-182-PEG3-K(palmitic acid)] not only showed improved stability but also increased affinity to the CD206 receptor through enhanced interaction with a hydrophobic binding motif of CD206. Peptide 1a showed superior in vitro activity in cell-based assays of macrophage activation which was restricted to CD206high M2-polarized macrophages. Improvement in responses was disproportionally skewed toward improved induction of phagocytosis including cancer cell phagocytosis. Peptide 1a reprogrammed the immune landscape in genetically engineered murine KPC pancreatic tumors toward increased innate immune surveillance and improved tumor control and effectively suppressed tumor growth of murine B16 melanoma allografts.

Despite advances in immune checkpoint inhibitors, chemotherapy remains the standard therapy for patients with pancreatic ductal adenocarcinoma (PDAC). As the combinations of chemotherapy, including the FOLFIRINOX [5-fluorouracil, F; irinotecan, I; and oxaliplatin, O (FIO)] regimen, and immune checkpoint inhibitors have failed to demonstrate clinical benefit in patients with metastatic PDAC tumors, there is increasing interest in identifying therapeutic approaches to potentiate ICI efficacy in patients with PDAC. In this study, we report that neoadjuvant FOLFIRINOX-treated human PDAC tumors exhibit increased MEK/ERK activation. We also show elevated MEK/ERK signaling in ex vivo PDAC slice cultures and cell lines treated with a combination of FIO. In addition, we find that the KPC-FIO cells, established from repeated treatment of mouse PDAC cell lines with six to eight cycles of FIO, display enhanced ERK phosphorylation and demonstrate increased sensitivity to MEK inhibition in vitro and in vivo. Significantly, the KPC-FIO cells develop tumors with a proinflammatory immune profile similar to human PDAC tumors after neoadjuvant FOLFIRINOX treatment. Furthermore, we found that the MEK inhibitor trametinib enables additional infiltration of highly functional CD8+ T cells into the KPC-FIO tumors and potentiates the efficacy of anti-PD-1 antibody in syngeneic mouse models. Our findings provide a rationale for combining trametinib and anti-PD-1 antibodies in patients with PDAC after neoadjuvant or short-term FOLFIRINOX treatment to achieve effective antitumor responses.

Mutations in the TP53 tumor suppressor genes are prevalent in aggressive cancers. Pharmacological reactivation of dysfunctional p53 due to mutations is a promising strategy for treating such cancers. Recently, a multifunctional proline- and glutamine-rich protein, PTB-associated splicing factor (PSF), was identified as a key driver of aggressive cancers. PSF promotes the expression of numerous oncogenes by modulating epigenetic and splicing mechanisms. We previously screened a small-molecule library and discovered compound No.10-3 as a potent PSF inhibitor. Here, we report the discovery of a No.10-3 analog, C-30, as a potent PSF inhibitor. Compared to No.10-3, C-30 treatment specifically suppressed the growth and induced apoptosis of mutant p53-bearing and therapy-resistant cancer cells. Interestingly, C-30 activated a set of p53-regulated genes in therapy-resistant cancer cells. A comprehensive analysis of PSF and p53 binding regions demonstrated a higher level of PSF-binding potential in mutant p53-expressing cancer cells around genomic regions identified as p53-binding peaks in p53-wild type cancer cells. Treatment of mutant p53-expressing cancer cells with C-30 decreases PSF binding around these sites, leading to activated histone acetylation. We further demonstrated that C-30 impaired tumor growth and increased the expression of p53-target genes in vivo. These results suggested that C-30 produces tumor-suppressive effects similar to the functional reactivation of p53, providing a rationale for the inhibition of PSF activity as a promising therapy against treatment-resistant cancer.

Pyruvate dehydrogenase complex is a crucial enzyme involved in the oxidation of glucose. It is regulated by pyruvate dehydrogenase kinase (PDHK) and pyruvate dehydrogenase phosphatase. Studies have demonstrated that PDHK1, a key enzyme in glucose metabolism, behaves like oncogenes. It is highly expressed in tumors and is associated with poor patient prognosis. However, there is limited research on how PDHK1 affects immune cell function. We have established a model of NK cell exhaustion to investigate the impact of dichloroacetate (DCA) on NK cell function. The production of granzyme B, IFNγ, TNFα, and CD107a by NK cells was explored by flow cytometry. The real-time live-cell imaging system was used to monitor the ability of NK cells against tumor cells. The Seahorse analyzer was utilized to measure the oxygen consumption rate and extracellular acidification rate of NK cells. A mouse model was used to investigate the potential of combining DCA with adjuvant NK cell infusion. Our study demonstrated that the hepatocellular carcinoma microenvironment mediated NK cellular exhaustion and high expression of PDHK1 and reduced cytokine secretion. We discovered that the PDHK1 inhibitor DCA enhances the activity and function of exhausted NK cells infiltrating the tumor microenvironment. Furthermore, in a s.c. hepatocellular carcinoma mouse model, DCA combined with NK cell treatment resulted in retarding cancer progression. This study indicates the potential of DCA in rescuing NK cell exhaustion and eliciting antitumor immunity.

Targeting synthetic lethal interactions among genes has emerged as a promising strategy for cancer therapy. This study explores the intricate interplay among terminal uridylyltransferase 4 (TUT4) and terminal uridylyltransferase 7 (TUT7), the 3'-5' exoribonuclease DIS3L2, and the superkiller (SKI) complex-interacting factor focadhesin (FOCAD) in the context of cancer vulnerability. Using CRISPR and public functional genomics data, we show impairment of cell proliferation upon knockout of TUT7 or DIS3L2, but not TUT4, on cancer cells with FOCAD loss. Moreover, we report the characterization of the first potent and selective TUT4/7 inhibitors that substantially reduce uridylation and demonstrate in vitro and in vivo antiproliferative activity specifically in FOCAD-deleted cancer. FOCAD deficiency posttranscriptionally disrupts the stability of the SKI complex, whose role is to safeguard cells against aberrant RNA. Reintroduction of FOCAD restores the SKI complex and makes these cells less sensitive to TUT4/7 inhibitors, indicating that TUT7 dependency is driven by FOCAD loss. We propose a model in which, in the absence of FOCAD, TUT7 and DIS3L2 function as a salvage mechanism that degrades aberrant RNA, and genetic or pharmacologic inhibition of this pathway leads to cell death. Our findings underscore the significance of FOCAD loss as a genetic driver of TUT7 vulnerability and provide insights into the potential utility of TUT4/7 inhibitors for cancer treatment.

Oxidative phosphorylation is an essential metabolic process for cancer proliferation and therapy resistance. The ClpXP complex maintains mitochondrial proteostasis by degrading misfolded proteins. Madera Therapeutics has developed a class of highly potent and selective small-molecule activators (TR compounds) of the ClpXP component caseinolytic peptidase proteolytic subunit (ClpP). This approach to cancer therapy eliminates substrate recognition and activates nonspecific protease function within mitochondria, which has shown encouraging preclinical efficacy in multiple malignancies. The class-leading compound TR-107 has demonstrated significantly improved potency in ClpP affinity and activation and enhanced pharmacokinetic properties over the multitargeting clinical agent ONC201. In this study, we investigate the in vitro efficacy of TR-107 against human colorectal cancer cells. TR-107 inhibited colorectal cancer cell proliferation in a dose- and time-dependent manner and induced cell cycle arrest at low nanomolar concentrations. Mechanistically, TR-107 downregulated the expression of proteins involved in the mitochondrial unfolded protein response and mitochondrial DNA transcription and translation. TR-107 attenuated oxygen consumption rate and glycolytic compensation, confirming inactivation of oxidative phosphorylation and a reduction in total cellular respiration. Multiomics analysis of treated cells indicated a downregulation of respiratory chain complex subunits and an upregulation of mitophagy and ferroptosis pathways. Further evaluation of ferroptosis revealed a depletion of antioxidant and iron toxicity defenses that could potentiate sensitivity to combinatory chemotherapeutics. Together, this study provides evidence and insight into the subcellular mechanisms employed by colorectal cancer cells in response to potent ClpP agonism. Our findings demonstrate a productive approach to disrupting mitochondrial metabolism, supporting the translational potential of TR-107.

Despite notable progress in the treatment of advanced head and neck squamous cell carcinoma (HNSCC), survival remains poor in patients with recurrent and/or metastatic (R/M) human papillomavirus (HPV)-negative HNSCC. Worse outcomes in patients who are HPV-negative may be partly related to loss of cell-cycle regulators and tumor suppressors as well as a noninflamed and hypoxic tumor microenvironment, both of which contribute to treatment resistance and disease progression. Anti-programmed cell death protein 1-based regimens as current standard-of-care treatment for R/M HNSCC are associated with durable responses in a limited number of patients. The anti-EGFR mAb, cetuximab, has antitumor activity in this treatment setting, but responses are short-lived and inevitably curtailed due to treatment resistance. Crosstalk between the EGFR and hepatocyte growth factor-dependent mesenchymal-epithelial transition (c-MET) receptor tyrosine kinase pathway is a known mechanism of resistance to cetuximab. Dual targeting of EGFR and c-MET pathways may overcome resistance to cetuximab in patients with HPV-negative HNSCC. Here, we review clinical data of treatments evaluated in patients with R/M HPV-negative HNSCC and highlight the potential role of combining hepatocyte growth factor/c-MET and EGFR pathway inhibitors to overcome cetuximab resistance in this population.

In patients with the rare adult-type granulosa cell tumors (aGCT), surgery is the primary treatment for both primary and recurrent disease. In cases of inoperable disease, systematic therapy is administered, but variable response rates and drug resistance complicate predicting the most effective therapy. Drug screen testing on patient-derived cell lines may offer a solution. In a national prospective study on aGCT, fresh tissue was cultured into 2D cell lines, testing 27 clinically and experimental drugs. Dose-response curves and synergy were calculated using GraphPad Prism and Compusyn software. We established 34 patient-derived cell lines from tissue of 20 adult granulosa cell tumor patients. Of these, seven patients had a primary diagnosis of adult granulosa cell tumor and 13 patients had recurrent disease. In eight patients multiple tumor locations were cultured. On each cell line 10 monotherapies and 17 combinations of drugs were tested. Carboplatin/gemcitabine showed efficacy and synergy in almost all patient-derived cell lines. Synergy could not be detected in the regular carboplatin/paclitaxel and carboplatin/etoposide combinations. Experimental combinations alpelisib/fulvestrant and alpelisib/gemcitabine showed efficacy of more than 75%. Drug screens on patient-derived tumor cell lines reflects the reality of the variable response of systemic therapy in aGCT patients. In future research, this technique may be used to personalize the systemic treatment of aGCT patients in a clinical study. The good response to carboplatin/gemcitabine in our patient-derived cell lines can then be confirmed in a clinical setting.

Bispecific antibodies (BsAbs) and antibody-drug conjugates (ADCs) have shown significant promise in cancer treatment, enhancing drug selectivity and therapeutic efficacy as demonstrated in multiple clinical studies. Bispecific antibody-drug conjugates (BsADCs), which combine the targeting capabilities of BsAbs with the cytotoxic potential of ADCs, offer a novel approach to overcoming several challenges associated with ADCs, including limited internalization, off-target toxicity, and drug resistance. In this study, we identified solute carrier family 3 member 2 (SLC3A2) as a highly expressed protein in a variety of solid tumors, making it a promising therapeutic target. We developed a bispecific antibody targeting SLC3A2 and PD-L1, and conjugated it to monomethyl auristatin E (MMAE) to create the SLC3A2/PD-L1 BsADC. The SLC3A2/PD-L1 BsAb effectively blocked PD-1 binding to PD-L1 and activated T cells, while also facilitating lysosomal targeting and degradation of poorly internalized PD-L1 antibodies. The SLC3A2/PD-L1 BsADC demonstrated superior anti-tumor efficacy in PD-L1 low-expressing tumor cells compared to single-target ADCs in both in vitro studies and in multiple xenograft and immunocompetent mouse models. Overall, our engineered SLC3A2/PD-L1 BsADC exhibited enhanced internalization and improved tumor cell targeting, highlighting the potential of lysosome-targeting BsAbs in advancing ADC therapeutic strategies for solid tumors.