Stilbene 5c, a microtubule poison with vascular disrupting properties that induces multiple modes of growth arrest and cell death

Non-Canonical Programmed Cell Death in Colon Cancer

Simple Summary

Non-canonical PCD is an important player in colon cancer cell suicide. It influences colon cancer in many ways, such as through tumorigenesis, treatment, and prognosis. In this review, we present the mechanism, application, and prospect of different types of non-canonical PCD in colon cancer.

Abstract

Programmed cell death (PCD) is an evolutionarily conserved process of cell suicide that is regulated by various genes and the interaction of multiple signal pathways. Non-canonical programmed cell death (PCD) represents different signaling excluding apoptosis. Colon cancer is the third most incident and the fourth most mortal worldwide. Multiple factors such as alcohol, obesity, and genetic and epigenetic alternations contribute to the carcinogenesis of colon cancer. In recent years, emerging evidence has suggested that diverse types of non-canonical programmed cell death are involved in the initiation and development of colon cancer, including mitotic catastrophe, ferroptosis, pyroptosis, necroptosis, parthanatos, oxeiptosis, NETosis, PANoptosis, and entosis. In this review, we summarized the association of different types of non-canonical PCD with tumorigenesis, progression, prevention, treatments, and prognosis of colon cancer. In addition, the prospect of drug-resistant colon cancer therapy related to non-canonical PCD, and the interaction between different types of non-canonical PCD, was systemically reviewed.

The resveratrol analogue, 3,4,5,4'‑trans-tetramethoxystilbene, inhibits the growth of A375 melanoma cells through multiple anticancer modes of action

Resveratrol is a natural dietary product that has demonstrated multifaceted anticancer activity. Several analogues of resveratrol have been synthesized in an effort to enhance the pharmacological potency and improve the pharmacokinetic properties of the compound. 3,4,5,4'‑trans‑tetramethoxystilbene (3,4,5,4'‑TMS) is a methoxylated analogue of resveratrol that has demonstrated anti-proliferative activity in vitro (in cancer cell lines) and in vivo (in xenograft models). In the present study, the anticancer effects of 3,4,5,4'‑TMS in A375 human melanoma cells were examined. 3,4,5,4'‑TMS markedly inhibited the proliferation of A375 cells (IC50=0.7 µM), via a mechanism involving mitotic arrest at the prometaphase stage of cell division. This effect was accompanied by the upregulation of the expression of the mitogen activated protein kinases, JNK and p38, and the concomitant activation of p38, that was verified by the nuclear translocation of the phoshorylated form of the protein. The pharmacological inhibition of p38 by SB203580 (4 µM) attenuated the effects of 3,4,5,4'‑TMS, as demonstrated by decreased cell cycle progression at the mitotic phase. Furthermore, 3,4,5,4'‑TMS increased the total levels of Aurora A, while it inhibited the localization of the protein to the spindle poles. Finally, 3,4,5,4'‑TMS exhibited anti-metastatic activity, inhibiting A375 cell migration and the attachment of the cells to a collagen type IV-coated surface. Collectively, the data suggest that 3,4,5,4'‑TMS is an effective chemotherapeutic drug for the treatment of human melanoma and that it exerts its effects through multiple anticancer modes of action.

Colchicine induces autophagy and senescence in lung cancer cells at clinically admissible concentration: potential use of colchicine in combination with autophagy inhibitor in cancer therapy

Colchicine is a well-known and potent microtubule targeting agent, but the therapeutic value of colchicine against cancer is limited by its toxicity against normal cells. But, there is no report of its cytotoxic potential against lung cancer cell, at clinically permissible or lower concentrations, minimally toxic to non-cancerous cells. Hence, in the present study, we investigated the possible mechanism by which the efficacy of colchicine against lung cancer cells at less toxic dose could be enhanced. Colchicine at clinically admissible concentration of 2.5 nM had no cytotoxic effect and caused no G2/M arrest in A549 cells. However, at this concentration, colchicine strongly hindered the reformation of cold depolymerised interphase and spindle microtubule. Colchicine induced senescence and reactive oxygen species mediated autophagy in A549 cells at this concentration. Autophagy inhibitor 3-methyladenine (3-MA) sensitised the cytotoxicity of colchicine in A549 cells by switching senescence to apoptotic death, and this combination had reduced cytotoxicity to normal lung fibroblast cells (WI38). Together, these findings indicated the possible use of colchicine at clinically relevant dose along with autophagy inhibitor in cancer therapy.

Viriditoxin regulates apoptosis and autophagy via mitotic catastrophe and microtubule formation in human prostate cancer cells

Microtubule targeting chemicals are considered excellent antitumor drugs through their binding to tubulin, which affects the instability of microtubules resulting in arrest of cancer cells. The present study was designed to investigate the antitumor effects of viriditoxin (VDT) against human prostate cancer cells. VDT, isolated from Paecilomyces variotii fungus, which was derived from the jellyfish Nemopilema nomurai, offers a new approach for controlling resistant bacterial infections by blocking bacterial cell division proteins. VDT produced dose-dependent cytotoxicity against human prostate cancer cells. Treatment with VDT promoted both apoptosis and autophagy in LNCaP cells. Annexin V/FITC staining indicated that apoptosis occurred in VDT-treated LNCaP cells. DAPI staining revealed morphological changes in the cell nuclei indicative of mitotic catastrophe in LNCaP cells. VDT caused cell growth inhibition via G2/M phase arrest. Moreover, VDT also increased autophagic cell death in LNCaP cells by induction of several autophagy-related proteins such as LC3 II, Atg5, Atg7 and beclin-1 protein, which are essential for autophagy induction. These results were also confirmed by acridine orange staining. This study indicates that VDT could potentially be effective against prostate cancer by promoting multiple modes of growth arrest and cell death coupled with apoptosis and autophagy.

Dynamic bioluminescence and fluorescence imaging of the effects of the antivascular agent Combretastatin-A4P (CA4P) on brain tumor xenografts

Combretastatin A-4 (CA4) is a natural product isolated from Combretum caffrum that inhibits tubulin polymerization by binding to the colchicine-binding site. A corresponding water soluble pro-drug (referred to as CA4P), has undergone extensive clinical trials and has been evaluated in pre-clinical studies using multiple modalities. We previously reported a novel assay based on dynamic bioluminescent imaging to assess tumor vascular disruption and now present its application to assessing multiple tumors simultaneously. The current study evaluated the vascular-disrupting activity of CA4P on subcutaneous 9L rat brain tumor xenografts in mice using dynamic bioluminescence imaging. A single dose of CA4P (120 mg/kg, intraperitoneally) induced rapid, temporary tumor vascular shutdown revealed by a rapid and reproducible decrease of light emission from luciferase-expressing 9L tumors following administration of luciferin as a substrate. A time-dependent reduction of tumor perfusion after CA4P treatment was confirmed by immunohistological assessment of the perfusion marker Hoechst 33342 and the tumor vasculature marker CD31. The vasculature showed distinct recovery within 24 h post therapy. Multiple tumors behaved similarly, although a size dependent vascular inhibition was observed. In conclusion, CA4P caused rapid, temporary tumor vascular shutdown and led to reduction of tumor perfusion in rat brain tumor xenografts and the multiple tumor approach should lead to more efficient studies requiring fewer animals and greater consistency.