Vincristine promotes differential levels of apoptosis, mitotic catastrophe, and senescence depending on the genetic background of glioblastoma cells

Cellular senescence in reproduction: a two-edged sword†

Cellular senescence (CS) is the state when cells are no longer capable to divide even after stimulation with grown factors. Cells that begin to undergo CS stop in the cell cycle and enter a suspended state without committing to programmed cell death. These cells assume a specific phenotype and influence their microenvironment by secreting molecules and extracellular vesicles that are part of the so-called senescent cell-associated secretory phenotype (SASP). Cellular senescence is intertwined with physiological and pathological conditions in the human organism. In terms of reproduction, senescent cells are present from reproductive tissues and germ cells to gestational tissues, and participate from fertilization to delivery, going through adverse reproductive outcomes such as pregnancy losses. Furthermore, various SASP molecules are enriched in gestational tissues throughout pregnancy. Thus, the aim of this review is to provide a basis about the features and potential roles played by CS throughout the reproductive process, encompassing its implication in each step of it and proposing a way to manage it in adverse reproductive contexts.

The rational modulation of autophagy sensitizes colorectal cancer cells to 5-fluouracil and oxaliplatin

Colorectal cancer (CRC) is the third most common and deadliest cancer globally. Regimens using 5-fluorouracil (5FU) and Oxaliplatin (OXA) are the first-line treatment for CRC, but tumor recurrence is frequent. It is plausible to hypothesize that differential cellular responses are triggered after treatments depending on the genetic background of CRC cells and that the rational modulation of cell tolerance mechanisms like autophagy may reduce the regrowth of CRC cells. This study proposes investigating the cellular mechanisms triggered by CRC cells exposed to 5FU and OXA using a preclinical experimental design mimicking one cycle of the clinical regimen (i.e., 48 h of treatment repeated every 2 weeks). To test this, we treated CRC human cell lines HCT116 and HT29 with the 5FU and OXA, combined or not, for 48 h, followed by analysis for two additional weeks. Compared to single-drug treatments, the co-treatment reduced tumor cell regrowth, clonogenicity and stemness, phenotypes associated with tumor aggressiveness and poor prognosis in clinics. This effect was exerted by the induction of apoptosis and senescence only in the co-treatment. However, a week after treatment, cells that tolerated the treatment had high levels of autophagy features and restored the proliferative phenotype, resembling tumor recurrence. The pharmacologic suppression of early autophagy during its peak of occurrence, but not concomitant with chemotherapeutics, strongly reduced cell regrowth. Overall, our experimental model provides new insights into the cellular mechanisms that underlie the response and tolerance of CRC cells to 5FU and OXA, suggesting optimized, time-specific autophagy inhibition as a new avenue for improving the efficacy of current treatments.

Perspectives and mechanisms for targeting mitotic catastrophe in cancer treatment

Mitotic catastrophe is distinct from other cell death modes due to unique nuclear alterations characterized as multi and/or micronucleation. Mitotic catastrophe is a common and virtually unavoidable consequence during cancer therapy. However, a comprehensive understanding of mitotic catastrophe remains lacking. Herein, we summarize the anticancer drugs that induce mitotic catastrophe, including microtubule-targeting agents, spindle assembly checkpoint kinase inhibitors, DNA damage agents and DNA damage response inhibitors. Based on the relationships between mitotic catastrophe and other cell death modes, we thoroughly evaluated the roles played by mitotic catastrophe in cancer treatment as well as its advantages and disadvantages. Some strategies for overcoming its shortcomings while fully utilizing its advantages are summarized and proposed in this review. We also review how mitotic catastrophe regulates cancer immunotherapy. These summarized findings suggest that the induction of mitotic catastrophe can serve as a promising new therapeutic approach for overcoming apoptosis resistance and strengthening cancer immunotherapy.

Assessment of cell cycle progression and mitotic slippage by videomicroscopy

Senescence is a state of irreversible cell cycle arrest accompanied by the acquisition of the senescence-associated secretory phenotype (SASP), which is activated in response to a variety of damaging stimuli, including genotoxic therapy. Accumulating evidence indicates that mitotic stress also promotes entry into senescence. This occurs via a mechanism involving defective mitoses and mitotic arrest, followed by abortion of cell division and slippage in the G1 phase. In this process, mitotic slippage leads to the generation of senescent cells characterized by a large cell body and a multinucleated and/or enlarged nuclear size. Here, we provide a detailed protocol for the assessment of cell proliferation and mitotic slippage in colorectal cancer cells upon pharmacological inhibition of the mitotic kinesin KIF11, best known as EG5. This approach can be used for preliminary characterization of senescence induction by therapeutics, but requires validation with standard senescence assays.

Cellular senescence in glioma

INTRODUCTION

Glioma is the most common primary brain tumor and is often associated with treatment resistance and poor prognosis. Standard treatment typically involves radiotherapy and temozolomide-based chemotherapy, both of which induce cellular senescence-a tumor suppression mechanism.

DISCUSSION

Gliomas employ various mechanisms to bypass or escape senescence and remain in a proliferative state. Importantly, senescent cells remain viable and secrete a large number of factors collectively known as the senescence-associated secretory phenotype (SASP) that, paradoxically, also have pro-tumorigenic effects. Furthermore, senescent cells may represent one form of tumor dormancy and play a role in glioma recurrence and progression.

CONCLUSION

In this article, we delineate an overview of senescence in the context of gliomas, including the mechanisms that lead to senescence induction, bypass, and escape. Furthermore, we examine the role of senescent cells in the tumor microenvironment and their role in tumor progression and recurrence. Additionally, we highlight potential therapeutic opportunities for targeting senescence in glioma.

Development of the DNA-based voltammetric biosensor for detection of vincristine as anticancer drug

In the article presented herein, a deoxyribonucleic acid (DNA) biosensor is introduced for Vincristine determination in pharmaceutical preparations based on the modification of screen printed electrode (SPE) with double-stranded DNA (ds-DNA), polypyrrole (PP), peony-like CuO:Tb³⁺ nanostructure (P-L CuO:Tb³⁺ NS). The developed sensor indicated a wide linear response to Vincristine concentration ranged from 1.0 nM to 400.0 μM with a limit of detection as low as .21 nM. The intercalation of Vincristine with DNA guanine led to the response. The optimized parameters for the biosensor performance were ds-DNA/Vincristine interaction time, DNA concentration and type of buffer solution. The docking investigation confirm the minor groove interaction between guanine base at surface of or ds-DNA/PP/P-L CuO:Tb³⁺ NS/SPE and Vincristine. The proposed sensor could successfully determine Vincristine in Vincristine injections and biological fluids, with acceptable obtains.