Cardiac differentiation is modulated by anti-apoptotic signals in murine embryonic stem cells

BACKGROUND Embryonic stem cells(ESCs)serve as a crucial ex vivo model,representing epiblast cells derived from the inner cell mass of blastocyst-stage embryos.ESCs exhibit a unique combination of self-renewal potency,unlimited proliferation,and pluripotency.The latter is evident by the ability of the isolated cells to differ-entiate spontaneously into multiple cell lineages,representing the three primary embryonic germ layers.Multiple regulatory networks guide ESCs,directing their self-renewal and lineage-specific differentiation.Apoptosis,or programmed cell death,emerges as a key event involved in sculpting and forming various organs and structures ensuring proper embryonic development.How-ever,the molecular mechanisms underlying the dynamic interplay between diffe-rentiation and apoptosis remain poorly understood.AIM To investigate the regulatory impact of apoptosis on the early differentiation of ESCs into cardiac cells,using mouse ESC(mESC)models-mESC-B-cell lym-phoma 2(BCL-2),mESC-PIM-2,and mESC-metallothionein-1(MET-1)-which overexpress the anti-apoptotic genes Bcl-2,Pim-2,and Met-1,respectively.METHODS mESC-T2(wild-type),mESC-BCL-2,mESC-PIM-2,and mESC-MET-1 have been used to assess the effect of potentiated apoptotic signals on cardiac differentiation.The hanging drop method was adopted to generate embryoid bodies(EBs)and induce terminal differentiation of mESCs.The size of the generated EBs was measured in each condition compared to the wild type.At the functional level,the percentage of cardiac differentiation was measured by calculating the number of beating cardiomyocytes in the manipulated mESCs compared to the control.At the molecular level,quantitative reverse transcription-polymerase chain reaction was used to assess the mRNA expression of three cardiac markers:Troponin T,GATA4,and NKX2.5.Additionally,troponin T protein expression was evaluated through immunofluorescence and western blot assays.RESULTS Our findings showed that the upregulation of Bcl-2,Pim-2,and Met-1 genes led to a reduction in the size of the EBs derived from the manipulated mESCs,in comparison with their wild-type counterpart.Additionally,a decrease in the count of beating cardiomyocytes among differentiated cells was observed.Furthermore,the mRNA expression of three cardiac markers-troponin T,GATA4,and NKX2.5-was diminished in mESCs overexpressing the three anti-apoptotic genes compared to the control cell line.Moreover,the overexpression of the anti-apoptotic genes resulted in a reduction in troponin T protein expression.CONCLUSION Our findings revealed that the upregulation of Bcl-2,Pim-2,and Met-1 genes altered cardiac differentiation,providing insight into the intricate interplay between apoptosis and ESC fate determination.

Tissue-specific cancer stem/progenitor cells:Therapeutic implications

Surgical resection,chemotherapy,and radiation are the standard therapeutic modalities for treating cancer.These approaches are intended to target the more mature and rapidly dividing cancer cells.However,they spare the relatively quiescent and intrinsically resistant cancer stem cells(CSCs)subpopulation residing within the tumor tissue.Thus,a temporary eradication is achieved and the tumor bulk tends to revert supported by CSCs'resistant features.Based on their unique expression profile,the identification,isolation,and selective targeting of CSCs hold great promise for challenging treatment failure and reducing the risk of cancer recurrence.Yet,targeting CSCs is limited mainly by the irrelevance of the utilized cancer models.A new era of targeted and personalized anti-cancer therapies has been developed with cancer patient-derived organoids(PDOs)as a tool for establishing pre-clinical tumor models.Herein,we discuss the updated and presently available tissue-specific CSC markers in five highly occurring solid tumors.Additionally,we highlight the advantage and relevance of the threedimensional PDOs culture model as a platform for modeling cancer,evaluating the efficacy of CSC-based therapeutics,and predicting drug response in cancer patients.

Novel therapeutic diiminoquinone exhibits anticancer effects on human colorectal cancer cells in two-dimensional and threedimensional in vitro models

BACKGROUND Colorectal cancer(CRC) is the second leading cause of cancer-related mortality.Cancer stem cells(CSCs) in CRC, which are spared by many chemotherapeutics,have tumorigenic capacity and are believed to be the reason behind cancer relapse. So far, there have been no effective drugs to target colon CSCs. Diiminoquinone(DIQ) has shown promising effects on targeting colon cancer.However, there is limited research on the effects of DIQ on eradicating CSCs in CRC.AIM To investigate the anticancer potential of DIQ on colon CSCs in two-dimensional(2D) and three-dimensional(3D) models using colonospheres and patient-derived organoids.METHODS Various 2D methods have been used to assess the effect and the mechanism of DIQ on HCT116and HT29 cell lines including cell proliferation and viability assays, migration and invasion assays,immunofluorescence staining, and flow cytometry. The potency of DIQ was also assessed in 3D culture using the sphere formation assay and colon cancer patient-derived organoid model.RESULTS Our results showed that DIQ significantly inhibited cell proliferation, migration, and invasion in HCT116 and HT29 cell lines. DIQ treatment induced apoptosis along with an accumulation of HCT116 and HT29 cancer cells in the sub-G1 region and an increase in reactive oxygen species in both CRC cell lines. DIQ reduced sphere-forming and self-renewal ability of colon cancer HCT116and HT29 stem/progenitor cells at sub-toxic doses of 1 μmol/L. Mechanistically, DIQ targets CSCs by downregulating the main components of stem cell-related-catenin, AKT, and ERK oncogenic signaling pathways. Potently, DIQ displayed a highly significant decrease in both the count and the size of the organoids derived from colon cancer patients as compared to control and 5-fluorouracil conditions.CONCLUSION This study is the first documentation of the molecular mechanism of the novel anticancer therapeutic DIQ via targeting CSC, a promising compound that needs further investigation.

Drug resistance in metastatic castration-resistant prostate cancer:an update on the status quo

Prostate cancer(PCa)is a leading cause of cancer-related morbidity and mortality in men globally.Despite improvements in the diagnosis and treatment of PCa,a significant proportion of patients with high-risk localized disease and all patients with advanced disease at diagnosis will experience progression to metastatic castration-resistant prostate cancer(mCRPC).Multiple drugs are now approved as the standard of care treatments for patients with mCRPC that have been shown to prolong survival.Although the majority of patients will respond initially,primary and secondary resistance to these therapies make mCRPC an incurable disease.Several molecular mechanisms underlie the development of mCRPC,with the androgen receptor(AR)axis being the main driver as well as the key drug target.Understanding resistance mechanisms is crucial for discovering novel therapeutic strategies to delay or reverse the progression of the disease.In this review,we address the diverse mechanisms of drug resistance in mCRPC.In addition,we shed light on emerging targeted therapies currently being tested in clinical trials with promising potential to overcome mCRPC-drug resistance.