CNOT2 Is Critically Involved in Atorvastatin Induced Apoptotic and Autophagic Cell Death in Non-Small Cell Lung Cancers

Anticancer Potential of Indole Phytoalexins and Their Analogues

Indole phytoalexins, found in economically significant Cruciferae family plants, are synthesized in response to pathogen attacks or stress, serving as crucial components of plant defense mechanisms against bacterial and fungal infections. Furthermore, recent research indicates that these compounds hold promise for improving human health, particularly in terms of potential anticancer effects that have been observed in various studies. Since our last comprehensive overview in 2016 focusing on the antiproliferative effects of these substances, brassinin and camalexin have been the most extensively studied. This review analyses the multifaceted pharmacological effects of brassinin and camalexin, highlighting their anticancer potential. In this article, we also provide an overview of the antiproliferative activity of new synthetic analogs of indole phytoalexins, which were synthesized and tested at our university with the aim of enhancing efficacy compared to the parent compound.

Acetylcorynoline Induces Apoptosis and G2/M Phase Arrest through the c-Myc Signaling Pathway in Colon Cancer Cells

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide, and despite advances in treatment, survival rates are still low; therefore, the development of novel drugs is imperative. Acetylcorynoline (ACN) is derived from Corydalis ambigua Cham. et Schltdl tubers. The effect of ACN on colon cancer is still unknown. Therefore, we investigated its potential effects. Our data showed that ACN inhibited cell viability and proliferation. Moreover, ACN induced apoptosis and cell cycle arrest by inhibiting cell growth. In the present study, we hypothesized that ACN regulates c-Myc through CNOT2 or MID1IP1. ACN reduced the protein expression of oncogenic genes, decreased c-Myc half-life, and rapidly inhibited the serum stimulation response. Moreover, knockdown of CNOT2 and MID1IP1 with ACN increased apoptosis and further reduced the expression of oncogenes. In addition, ACN exhibited a synergistic effect with low-dose 5-fluorouracil (5-FU) and doxorubicin (Dox). Collectively, our data demonstrate that ACN inhibited c-Myc expression through CNOT2 and MID1IP1, and induced apoptosis. These findings indicate the potential of ACN as a therapeutic agent against colon cancer.

Gene regulatory Networks Reveal Sex Difference in Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) has been observed to have significant sex differences in incidence, prognosis, and response to therapy. However, the molecular mechanisms responsible for these disparities have not been investigated extensively. Sample-specific gene regulatory network methods were used to analyze RNA sequencing data from non-cancerous human lung samples from The Genotype Tissue Expression Project (GTEx) and lung adenocarcinoma primary tumor samples from The Cancer Genome Atlas (TCGA); results were validated on independent data. We observe that genes associated with key biological pathways including cell proliferation, immune response and drug metabolism are differentially regulated between males and females in both healthy lung tissue, as well as in tumor, and that these regulatory differences are further perturbed by tobacco smoking. We also uncovered significant sex bias in transcription factor targeting patterns of clinically actionable oncogenes and tumor suppressor genes, including AKT2 and KRAS. Using differentially regulated genes between healthy and tumor samples in conjunction with a drug repurposing tool, we identified several small-molecule drugs that might have sex-biased efficacy as cancer therapeutics and further validated this observation using an independent cell line database. These findings underscore the importance of including sex as a biological variable and considering gene regulatory processes in developing strategies for disease prevention and management.

The participation of non-canonical autophagic proteins in the autophagy process and their potential as therapeutic targets

INTRODUCTION

Autophagy is a conserved catabolic process that helps recycle intracellular components to maintain homeostasis. The completion of autophagy requires the synergistic effect of multiple canonical autophagic proteins. Defects in autophagy machinery have been reported to promote diseases, rendering autophagy a bone fide health-modifying agent. However, the clinical implication of canonical pan-autophagic activators or inhibitors has often led to undesirable side effects, making it urgent to find a safer autophagy-related therapeutic target. The discovery of non-canonical autophagic proteins has been found to specifically affect the development of diseases without causing a universal impact on autophagy and has shed light on finding a safer way to utilize autophagy in the therapeutic context.

AREAS COVERED

This review summarizes recently discovered non-canonical autophagic proteins, how these proteins influence autophagy, and their potential therapeutic role in the disease due to their interaction with autophagy.

EXPERT OPINION

Several therapies have been studied thus far and continued research is needed to identify the potential that non-canonical autophagic proteins have for treating certain diseases. In the meantime, continue to uncover new non-canonical autophagic proteins and examine which are likely to have therapeutic implications.

Antitumor Effect of Cycloastragenol in Colon Cancer Cells via p53 Activation

Colorectal cancer cell (CRC) is the fourth most common cancer in the world. There are several chemotherapy drugs available for its treatment, though they have side effects. Cycloastragenol (CY) is a compound from Astragalus membranaceus (Fisch.) Bge known to be effective in aging, anti-inflammatory, anticancer, and anti-heart failure treatments. Although many studies have demonstrated the functions of CY in cancer cells, no studies have shown the effects of p53 in colon cancer cells. In this study, we found that CY reduces the viability of colon cancer cells in p53 wild-type cells compared to p53 null cells and HT29. Furthermore, CY induces apoptosis by p53 activation in a dose- and time-dependent manner. And it was confirmed that it affects the L5 gene related to p53. Additionally, CY enhanced p53 expression compared to when either doxorubicin or 5-FU was used alone. Altogether, our findings suggest that CY induces apoptosis via p53 activation and inhibits the proliferation of colon cancer cells. In addition, apoptosis occurs in colon cancer cells due to other factors. Moreover, CY is expected to have a combined effect when used together with existing treatments for colon cancer in the future.

CircRNA.0007127 triggers apoptosis through the miR-513a-5p/CASP8 axis in K-562 cells

BACKGROUND: Circular RNAs (circRNAs) are covalently closed single-stranded RNAs with multiple biological functions. CircRNA.0007127 is derived from the carbon catabolite repression 4-negative on TATA-less (CCR4-NOT) complex subunit 2 (CNOT2), which was found to regulate tumor cell apoptosis through caspase pathway. METHODS: Potential circRNA.0007127 target microRNAs (miRNAs) were analyzed by miRanda, TargetScan, and RNAhybrid software, and the miRNAs with binding sites for apoptosis-related genes were screened. The roles of circRNA.0007127 and its downstream target, microRNA (miR)‍-513a-5p, were validated by quantitative real-time polymerase chain reaction (qPCR), flow cytometry, mitochondrial membrane potential, immunofluorescence, western blot, and caspase-8 (CASP8) protein activity in vitro in H₂O₂-induced K-562 cells. The circRNA.‍0007127‍‒‍miR-513a-5p and CASP8‍‒‍miR-513a-5p interactions were verified by luciferase reporter assays. RESULTS: Silencing circRNA.0007127 decreased cell apoptosis by inhibiting CASP8 pathway activation in K-562 cells. Compared with the control group, the expression of CASP8 was reduced by 50% and the 43-kD fragment of CASP8 protein was significantly reduced (P≤0.05). The luciferase reporting assay showed that circRNA.0007127 combined with miR-513a-5p or CASP8, with extremely significant differences (P≤0.001). The overexpression of miR-513a-5p inhibited the gene expression level of CASP8 in a human myeloid leukemia cell model (75% change) and the level of a 43-kD fragment of CASP8 protein (P≤0.01). The rescue experiment showed that cotransfection with circRNA.0007127 small-interfering RNA (siRNA) and the miR-513a-5p inhibitor increased CASP8 gene expression and the apoptosis rate, suggesting that the miR-513a-5p inhibitor is a circRNA.0007127 siRNA antagonist. CONCLUSIONS: CircRNA.0007127 regulates K-562 cell apoptosis through the miR-513a-5p/CASP8 axis, which can serve as a novel powerful molecular target for K-562 cells.

Pitavastatin Induces Cancer Cell Apoptosis by Blocking Autophagy Flux

Statins, a class of lipid-lowering drugs, are used in drug repositioning for treatment of human cancer. However, the molecular mechanisms underlying statin-induced cancer cell death and autophagy are not clearly defined. In the present study, we showed that pitavastatin could increase apoptosis in a FOXO3a-dependent manner in the oral cancer cell line, SCC15, and the colon cancer cell line, SW480, along with the blockade of autophagy flux. The inhibition of autophagy by silencing the LC3B gene reduced apoptosis, while blockade of autophagy flux using its inhibitor, Bafilomycin A1, further induced apoptosis upon pitavastatin treatment, which suggested that autophagy flux blockage was the cause of apoptosis by pitavastatin. Further, the FOXO3a protein accumulated due to the blockade of autophagy flux which in turn was associated with the induction of ER stress by transcriptional upregulation of PERK-CHOP pathway, subsequently causing apoptosis due to pitavastatin treatment. Taken together, pitavastatin-mediated blockade of autophagy flux caused an accumulation of FOXO3a protein, thereby leading to the induction of PERK, ultimately causing CHOP-mediated apoptosis in cancer cells. Thus, the present study highlighted the additional molecular mechanism underlying the role of autophagy flux blockade in inducing ER stress, eventually leading to apoptosis by pitavastatin.

Design and Characterization of Atorvastatin Dry Powder Formulation as a potential Lung Cancer Treatment

Lung cancer is the leading cause of cancer death. Many studies have shown the beneficial effects of Atorvastatin in decreasing the mortality risk and improving survival among patients with lung cancer. This research paper focuses on improving AVT cytotoxic activity and cellular uptake by developing mannitol microcarriers as a promising drug delivery system for lung cancer treatment and, studying the impact of improving inhalation deposition on the delivery and Dry Powder formulations efficiency. The AVT loaded mannitol (AM) microparticles (AVT-AM) formulation was prepared by spray drying and characterized for its physicochemical properties and aerodynamic deposition. The results revealed that the AVT-AM formulation has good flow properties and aerosol deposition with a particle size of 3418 nm ± 26.86. The formulation was also assessed in vitro for cytotoxicity effects (proliferation, apoptosis, and cell cycle progression) on A549 human lung adenocarcinoma. Compared with free AVT, the AVT-AM formulation has significantly higher cellular uptake and anti-cancer properties by disrupting cell cycle progression via either apoptosis or cell cycle arrest in the G2/M phase. This study shows that AVT loaded mannitol microcarriers may provide a potentially effective and sustained pulmonary drug delivery for lung cancer treatment.

Inhibition of CNOT2 Induces Apoptosis via MID1IP1 in Colorectal Cancer Cells by Activating p53

CCR4-NOT transcription complex subunit 2 (CNOT2), a subunit of the CCR4-NOT complex, has been described in cancer progression. The CNOT complex plays an important role in multiple cellular functions. Recent studies in our laboratory showed that CNOT2 promotes breast cancer cell proliferation and angiogenesis. In addition, CNOT2 signals are critically related to apoptosis induced by atorvastatin in lung cancer cells. Furthermore, depletion of CNOT2 was shown to enhance the antitumor effect of midline 1 interacting protein 1 (MID1IP1) depletion, thus inhibiting c-Myc expression in liver cancer cells. However, the molecular mechanisms related to its oncogenic role remain unclear. Herein, for the first time, we report that CNOT2 inhibition can induce apoptosis in colorectal cancer cells by activating p53. Inhibition of CNOT2 markedly induced apoptosis in various cancer cells like that of the wild-type p53. Furthermore, inhibition of CNOT2 elongated p53 s half-life. Previously, our laboratory demonstrated that MID1IP1 promoted colocalization with c-Myc mediated by CNOT2. Interestingly, inhibition of CNOT2 cannot induce p53 expression without MID1IP1 or apoptosis in cancer cells. In conclusion, our results demonstrate that CNOT2 inhibition induces apoptosis through MID1IP1 by activating p53.

Autophagy-related signaling pathways are involved in cancer (Review)

Autophagy is a self-digestion process in cells that can maintain energy homeostasis under normal circumstances. However, misfolded proteins, damaged mitochondria and other unwanted components in cells can be decomposed and reused via autophagy in some specific cases (including hypoxic stress, low energy states or nutrient deprivation). Therefore, autophagy serves a positive role in cell survival and growth. However, excessive autophagy may lead to apoptosis. Furthermore, abnormal autophagy may lead to carcinogenesis and promote tumorigenesis in normal cells. In tumor cells, autophagy may provide the energy required for excessive proliferation, promote the growth of cancer cells, and evade apoptosis caused by certain treatments, including radiotherapy and chemotherapy, resulting in increased treatment resistance and drug resistance. On the other hand, autophagy leads to an insufficient nutrient supply in cancer cells and the destruction of energy homeostasis, thereby inducing cancer cell apoptosis. Therefore, understanding the mechanism of the double-edged sword of autophagy is crucial for the treatment of cancer. The present review summarizes the signaling pathways and key factors involved in autophagy and cancer to provide possible strategies for treating tumors.

Diverse functions of deadenylases in DNA damage response and genomic integrity

DNA damage response (DDR) is a coordinated network of diverse cellular processes including the detection, signaling, and repair of DNA lesions, the adjustment of metabolic network and cell fate determination. To deal with the unavoidable DNA damage caused by either endogenous or exogenous stresses, the cells need to reshape the gene expression profile to allow efficient transcription and translation of DDR-responsive messenger RNAs (mRNAs) and to repress the nonessential mRNAs. A predominant method to adjust RNA fate is achieved by modulating the 3'-end oligo(A) or poly(A) length via the opposing actions of polyadenylation and deadenylation. Poly(A)-specific ribonuclease (PARN) and the carbon catabolite repressor 4 (CCR4)-Not complex, the major executors of deadenylation, are indispensable to DDR and genomic integrity in eukaryotic cells. PARN modulates cell cycle progression by regulating the stabilities of mRNAs and microRNA (miRNAs) involved in the p53 pathway and contributes to genomic stability by affecting the biogenesis of noncoding RNAs including miRNAs and telomeric RNA. The CCR4-Not complex is involved in diverse pathways of DDR including transcriptional regulation, signaling pathways, mRNA stabilities, translation regulation, and protein degradation. The RNA targets of deadenylases are tuned by the DDR signaling pathways, while in turn the deadenylases can regulate the levels of DNA damage-responsive proteins. The mutual feedback between deadenylases and the DDR signaling pathways allows the cells to precisely control DDR by dynamically adjusting the levels of sensors and effectors of the DDR signaling pathways. Here, the diverse functions of deadenylases in DDR are summarized and the underlying mechanisms are proposed according to recent findings. This article is categorized under: RNA Processing > 3' End Processing RNA in Disease and Development > RNA in Disease RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms.

Colocalization of MID1IP1 and c-Myc is Critically Involved in Liver Cancer Growth via Regulation of Ribosomal Protein L5 and L11 and CNOT2

Though midline1 interacting protein 1 (MID1IP1) was known as one of the glucose-responsive genes regulated by carbohydrate response element binding protein (ChREBP), the underlying mechanisms for its oncogenic role were never explored. Thus, in the present study, the underlying molecular mechanism of MID1P1 was elucidated mainly in HepG2 and Huh7 hepatocellular carcinoma cells (HCCs). MID1IP1 was highly expressed in HepG2, Huh7, SK-Hep1, PLC/PRF5, and immortalized hepatocyte LX-2 cells more than in normal hepatocyte AML-12 cells. MID1IP1 depletion reduced the viability and the number of colonies and also increased sub G1 population and the number of TUNEL-positive cells in HepG2 and Huh7 cells. Consistently, MID1IP1 depletion attenuated pro-poly (ADP-ribose) polymerase (pro-PARP), c-Myc and activated p21, while MID1IP1 overexpression activated c-Myc and reduced p21. Furthermore, MID1IP1 depletion synergistically attenuated c-Myc stability in HepG2 and Huh7 cells. Of note, MID1IP1 depletion upregulated the expression of ribosomal protein L5 or L11, while loss of L5 or L11 rescued c-Myc in MID1IP1 depleted HepG2 and Huh7 cells. Interestingly, tissue array showed that the overexpression of MID1IP1 was colocalized with c-Myc in human HCC tissues, which was verified in HepG2 and Huh7 cells by Immunofluorescence. Notably, depletion of CCR4-NOT2 (CNOT2) with adipogenic activity enhanced the antitumor effect of MID1IP1 depletion to reduce c-Myc, procaspase 3 and pro-PARP in HepG2, Huh7 and HCT116 cells. Overall, these findings provide novel insight that MID1IP1 promotes the growth of liver cancer via colocalization with c-Myc mediated by ribosomal proteins L5 and L11 and CNOT2 as a potent oncogenic molecule.

CCR4‑NOT transcription complex subunit 2 regulates TRAIL sensitivity in non‑small‑cell lung cancer cells via the STAT3 pathway

TRAIL is an attractive candidate for anticancer therapy in a variety of tumors since it targets only tumors and not normal tissue. However, a remaining major hurdle is that the majority of tumors exhibit a resistance mechanism against the effects of TRAIL via the induction of anti-apoptotic signaling pathways. In this study, we aimed to evaluate whether the modulation of CCR4-NOT transcription complex subunit 2 (CNOT2) function can promote TRAIL sensitivity in non-small-cell lung cancer (NSCLC) cells. CNOT2 depletion partially decreased colony numbers and the proliferation of NSCLC cells. When combined with TRAIL, the suppression of CNOT2 expression markedly decreased the survival rate and increased apoptosis, as compared with TRAIL treatment alone in TRAIL-resistant NSCLC cells. Of note, CNOT2 overexpression in TRAIL-sensitive H460 cells enhanced the survival rate and decreased apoptosis when compared with TRAIL treatment alone. Gene expression analysis indicated that genes involved in the signal transducer and activator of transcription 3 (STAT3) signaling pathway were dominantly altered in the CNOT2-depleted A549 cells. Under this condition, Src homology region 2 domain containing phosphatase-1 (SHP1) was significantly upregulated and subsequently increased apoptosis. On the whole, the findings of this study demonstrate that CNOT2 participates in TRAIL sensitivity in NSCLC cells via the regulation of the STAT3 signaling pathway, and suggest that combination therapy with CNOT2 depletion and TRAIL treatment may prove to be a useful strategy for overcoming TRAIL resistance in NSCLC.