ABT-737 and pictilisib synergistically enhance pitavastatin-induced apoptosis in ovarian cancer cells

Identification of SUMOylation-related biomarkers in papillary thyroid carcinoma

BACKGROUND

Small ubiquitin-like modifier (SUMO) modification is increasingly recognized as critical in tumorigenesis and progression. This study identifies biomarkers linked to SUMOylation in papillary thyroid carcinoma (PTC), aiming to advance therapeutic and prognostic strategies.

METHODS

Employing PTC datasets and SUMO related genes (SRGs), we utilized univariate Cox regression for prognosis-related SRGs, conducted differential expression analyses, and integrated findings to pinpoint candidate genes. These genes underwent further validation through survival, gene set enrichment, immune infiltration, and drug sensitivity analyses, including external validation via quantitative RT-qPCR. In our final step, we conducted immunohistochemical staining on tumor samples from PTC patients at our center and integrated this with their clinical data to validate BMP8A's effectiveness in predicting recurrence in PTC.

RESULTS

Three biomarkers-BMP8A, RGS8, and SERPIND1-emerged as significant. Gene Set Enrichment Analysis (GSEA) showed their involvement in immune-related pathways, with differential immune infiltration patterns and drug response correlations observed, underscoring their potential for targeted therapy. Lastly, we validated the efficacy of BMP8A in predicting the recurrence of PTC in patients using clinical and pathological data from our center.

CONCLUSION

The study identifies BMP8A, RGS8, and SERPIND1 as key biomarkers associated with SUMOylation in PTC. Their linkage to immune response and drug sensitivity highlights their importance as targets for therapeutic intervention and prognosis in PTC research.

Cancer Cell Membrane Wrapped Nanoparticles for the Delivery of a Bcl-2 Inhibitor to Triple-Negative Breast Cancer

Overexpression of the antiapoptotic protein B-cell lymphoma 2 (Bcl-2) is correlated with poor survival outcomes in triple-negative breast cancer (TNBC), making Bcl-2 inhibition a promising strategy to treat this aggressive disease. Unfortunately, Bcl-2 inhibitors developed to date have limited clinical success against solid tumors, owing to poor bioavailability, insufficient tumor delivery, and off-target toxicity. To circumvent these problems, we loaded the Bcl-2 inhibitor ABT-737 in poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) that were wrapped with phospholipid membranes derived from 4T1 murine mammary cancer cells, which mimic the growth and metastasis of human TNBC. We show that the biomimetic cancer cell membrane coating enabled the NPs to preferentially target 4T1 TNBC cells over noncancerous mammary epithelial cells in vitro and significantly increased NP accumulation in orthotopic 4T1 tumors in mice after intravenous injection by over 2-fold compared to poly(ethylene glycol)-poly(lactide-co-glycolic) (PEG-PLGA) copolymer NPs. Congruently, the ABT-737 loaded, cancer cell membrane-wrapped PLGA NPs (ABT CCNPs) induced higher levels of apoptosis in TNBC cells in vitro than ABT-737 delivered freely or in PEG-PLGA NPs. When tested in a syngeneic spontaneous metastasis model, the ABT CCNPs significantly increased apoptosis (evidenced by elevated active caspase-3 and decreased Bcl-2 staining) and decreased proliferation (denoted by reduced Ki67 staining) throughout tumors compared with saline or ABT-loaded PEG-PLGA NP controls. Moreover, the ABT CCNPs did not alter animal weight or blood composition, suggesting that the specificity afforded by the TNBC cell membrane coating mitigated the off-target adverse effects typically associated with ABT-737. Despite these promising results, the low dose of ABT CCNPs administered only modestly reduced primary tumor growth and metastatic nodule formation in the lungs relative to controls. We posit that increasing the dose of ABT CCNPs, altering the treatment schedule, or encapsulating a more potent Bcl-2 inhibitor may yield more robust effects on tumor growth and metastasis. With further development, drug-loaded biomimetic NPs may safely treat solid tumors such as TNBC that are characterized by Bcl-2 overexpression.

Advances in ovarian cancer treatment using a combination of statins with other drugs

New anti-cancer drugs are constantly being developed, especially targeted drugs. Although these drugs have achieved significant clinical efficacy, they do not play a significant role in ovarian cancer. Moreover, the research cycle and costs of such drugs are often huge. The repositioning of conventional drugs has gradually become a concern. Statins, as traditional lipid-lowering drugs, play a role mainly by inhibiting HMGCR. In recent years, epidemiological studies and in vitro experiments have confirmed its anti-cancer effect, especially the effect of anti-ovarian cancer. The mutation rate of TP53 in ovarian cancer is as high as 95%, while HMGCR is often highly expressed in TP53 mutant tumors. However, the effect of prospective clinical trials is not ideal. This result seems understandable considering that it seems unrealistic for a lipid-lowering drug to completely inhibit tumor growth. Therefore, statins play more synergistic roles in the treatment of ovarian cancer. Because ovarian cancer is a highly heterogeneous tumor, it may be a good choice to deeply understand the mechanism of statins in the treatment of ovarian cancer and achieve precise treatment by combining it with other drugs.

Targeting the Mevalonate Pathway in Cancer

The mevalonate synthesis inhibitors, statins, are mainstay therapeutics for cholesterol management and cardiovascular health. Thirty years of research have uncovered supportive roles for the mevalonate pathway in numerous cellular processes that support oncogenesis, most recently macropinocytosis. Central to the diverse mechanisms of statin sensitivity is an acquired dependence on one mevalonate pathway output, protein geranylgeranylation. New chemical prenylation probes and the discovery of a novel geranylgeranyl transferase hold promise to deepen our understanding of statin mechanisms of action. Further, insights into statin selection and the counterproductive role of dietary geranylgeraniol highlight how we should assess statins in the clinic. Lastly, rational combination strategies preview how statins will enter the oncology toolbox.

Mechanisms of Taxane Resistance

The taxane family of chemotherapy drugs has been used to treat a variety of mostly epithelial-derived tumors and remain the first-line treatment for some cancers. Despite the improved survival time and reduction of tumor size observed in some patients, many have no response to the drugs or develop resistance over time. Taxane resistance is multi-faceted and involves multiple pathways in proliferation, apoptosis, metabolism, and the transport of foreign substances. In this review, we dive deeper into hypothesized resistance mechanisms from research during the last decade, with a focus on the cancer types that use taxanes as first-line treatment but frequently develop resistance to them. Furthermore, we will discuss current clinical inhibitors and those yet to be approved that target key pathways or proteins and aim to reverse resistance in combination with taxanes or individually. Lastly, we will highlight taxane response biomarkers, specific genes with monitored expression and correlated with response to taxanes, mentioning those currently being used and those that should be adopted. The future directions of taxanes involve more personalized approaches to treatment by tailoring drug-inhibitor combinations or alternatives depending on levels of resistance biomarkers. We hope that this review will identify gaps in knowledge surrounding taxane resistance that future research or clinical trials can overcome.

Pitavastatin induces apoptosis in oral squamous cell carcinoma through activation of FOXO3a

Statins are a class of lipid‐lowering drugs that have recently been used in drug repositioning in the treatment of human cancer. However, the underlying mechanism of statin‐induced cancer cell death has not been clearly defined. In the present study, we evaluated the anticancer effect of pitavastatin on oral squamous cell carcinoma (OSCC), SCC15 and SCC4 cells and found that FOXO3a might be a direct target in pitavastatin‐induced cancer cell death. Our data revealed that pitavastatin selectively suppressed cell viability and induced intrinsic apoptosis in a FOXO3a‐dependent manner in SCC15 cells while no effect was observed in SCC4 cells. Notably, treatment with pitavastatin in SCC15 cells induced the nuclear translocation of FOXO3a via dual regulation of two upstream kinases, AMPK and Akt, resulting in the up‐regulation of PUMA, a transcriptional target gene of FOXO3a. Furthermore, our data revealed that FOXO3a‐mediated PUMA induction plays a role in pitavastatin‐induced intrinsic apoptosis in SCC15 cells. Taken together, our findings suggest that pitavastatin activates the FOXO3a/PUMA apoptotic axis by regulation of nuclear translocation of FOXO3a via Akt/FOXO3a or AMPK/FOXO3a signalling. Therefore, these findings might help to elucidate the underlying mechanism of the anticancer effects of pitavastatin on OSCC.

Therapeutic Inducers of Apoptosis in Ovarian Cancer

Ovarian cancers remain one of the most common causes of gynecologic cancer-related death in women worldwide. The standard treatment comprises platinum-based chemotherapy, and most tumors develop resistance to therapeutic drugs. One mechanism of developing drug resistance is alterations of molecules involved in apoptosis, ultimately assisting in the cells' capability to evade death. Thus, there is a need to focus on identifying potential drugs that restore apoptosis in cancer cells. Here, we discuss the major inducers of apoptosis mediated through various mechanisms and their usefulness as potential future treatment options for ovarian cancer. Broadly, they can target the apoptotic pathways directly or affect apoptosis indirectly through major cancer-pathways in cells. The direct apoptotic targets include the Bcl-2 family of proteins and the inhibitor of apoptotic proteins (IAPs). However, indirect targets include processes related to homologous recombination DNA repair, micro-RNA, and p53 mutation. Besides, apoptosis inducers may also disturb major pathways converging into apoptotic signals including janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3), wingless-related integration site (Wnt)/β-Catenin, mesenchymal-epithelial transition factor (MET)/hepatocyte growth factor (HGF), mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK), and phosphatidylinositol 3-kinase (PI3K)/v-AKT murine thymoma viral oncogene homologue (AKT)/mammalian target of rapamycin (mTOR) pathways. Several drugs in our review are undergoing clinical trials, for example, birinapant, DEBIO-1143, Alisertib, and other small molecules are in preclinical investigations showing promising results in combination with chemotherapy. Molecules that exhibit better efficacy in the treatment of chemo-resistant cancer cells are of interest but require more extensive preclinical and clinical evaluation.