Design, synthesis and pharmacological evaluation of β-carboline derivatives as potential antitumor agent via targeting autophagy

Design, synthesis of combretastatin A-4 piperazine derivatives as potential antitumor agents by inhibiting tubulin polymerization and inducing autophagy in HCT116 cells

A series of combretastatin A-4 (CA-4) derivatives were designed and synthesized, which contain stilbene core structure with different linker, predominantly piperazine derivatives. These compounds were evaluated for their cytotoxic activities against four cancer cell lines, HCT116, A549, AGS, and SK-MES-1. Among them, compound 13 displayed the best effectiveness with IC50 values of 0.227 μM and 0.253 μM against HCT116 and A549 cells, respectively, showing low toxicity to normal cells. Mechanistic studies showed that 13 inhibited HCT116 proliferation via arresting cell cycle at the G2/M phase through disrupting the microtubule network and inducing autophagy in HCT116 cells by regulating the expression levels of autophagy-related proteins. In addition, 13 displayed antiproliferative activities against A549 cells through blocking the cell cycle and inducing A549 cells apoptosis. Because of the poor water solubility of 13, four carbohydrate conjugates were synthesized which exhibited better water solubility. Further investigations revealed that 13 showed positive effects in vivo anticancer study with HCT116 xenograft models. These data suggest that 13 could be served as a promising lead compound for further development of anti-colon carcinoma agent.

Dual role of autophagy for advancements from conventional to new delivery systems in cancer

Autophagy, a programmed cell-lysis mechanism, holds significant promise in the prevention and treatment of a wide range of conditions, including cancer, Alzheimer's, and Parkinson's disease. The successful utilization of autophagy modulation for therapeutic purposes hinges upon accurately determining the role of autophagy in disease progression, whether it acts as a cytotoxic or cytoprotective factor. This critical knowledge empowers scientists to effectively manipulate tumor sensitivity to anti-cancer therapies through autophagy modulation, while also circumventing drug resistance. However, conventional therapies face limitations such as low bioavailability, poor solubility, and a lack of controlled release mechanisms, hindering their clinical applicability. In this regard, innovative nanoplatforms including organic and inorganic systems have emerged as promising solutions to offer stimuli-responsive, theranostic-controlled drug delivery systems with active targeting and improved solubility. The review article explores a variety of organic nanoplatforms, such as lipid-based, polymer-based, and DNA-based systems, which incorporate autophagy-inhibiting drugs like hydroxychloroquine. By inhibiting the glycolytic pathway and depriving cells of essential nutrients, these platforms exhibit tumor-suppressive effects in advanced forms of cancer such as leukemia, colon cancer, and glioblastoma. Furthermore, metal-based, metal-oxide-based, silica-based, and quantum dot-based nanoplatforms selectively induce autophagy in tumors, leading to extensive cancer cell destruction. Additionally, this article discusses the current clinical status of autophagy-modulating drugs for cancer therapy with valuable insights of progress and potential of such approaches.

Design, Synthesis and Antiproliferative Evaluation of Bis-Indole Derivatives with a Phenyl Linker: Focus on Autophagy

This work deals with the study of the synthesis of new bis-indole analogues with a phenyl linker derived from indole phytoalexins. Synthesis of target bis-indole thiourea linked by a phenyl linker was achieved by the reaction of [1-(tert-butoxycarbonyl)indol-3-yl]methyl isothiocyanate with p-phenylenediamine. By replacing the sulfur of the thiocarbonyl group in bis-indole thiourea with oxygen using mesityl nitrile oxide, a bis-indole homodimer with a urea group was obtained. A cyclization protocol utilizing bis-indole thiourea and methyl bromoacetate was applied to synthesize a bis-indole homodimer with a thiazolidin-4-one moiety. Bis-indole homodimers derived from 1-methoxyspirobrassinol methyl ether were prepared by bromospirocyclization methodology. Among the synthesized analogues, compound 49 was selected for further study. To evaluate the mode of the mechanism of action, we used flow cytometry, Western blot, and spectroscopic analyses. Compound 49 significantly inhibited the proliferation of lung cancer cell line A549 with minimal effects on the non-cancer cells. We also demonstrated that compound 49 induced autophagy through the upregulation of Beclin-1, LC3A/B, Atg7 and AMPK and ULK1. Furthermore, chloroquine (CQ; an autophagy inhibitor) in combination with compound 49 decreased cell proliferation and induced G1 cell cycle arrest and apoptosis. Compound 49 also caused GSH depletion and significantly potentiated the antiproliferative effect of cis-platin.