Autophagy induction and antiproliferative effect of a novel curcumin derivative MOMI‐1 on the human lung cancer cells A549

Non-coding transcribed ultraconserved region uc.290 in colon mucosa promotes intestinal fibrosis in chronic active ulcerative colitis

BACKGROUND AND AIMS

TGF-β1 induces epithelial-mesenchymal transition (EMT) and leads to intestinal fibrosis in ulcerative colitis (UC). We aimed to investigate the expression of transcribed ultraconserved region uc.290 in chronic UC and its role in intestinal fibrosis.

METHODS

Colon specimens were taken from thirty chronic active UC, chronic inactive UC and healthy controls respectively. Modified Mayo score, expressions of uc.290, TGF-β1, EMT biomarkers (Vimentin, α-SMA and E-cadherin) and intestinal fibrosis biomarker (collagen Ⅲ) in colon biopsy specimens were determined in human. Expressions of TGF-β1, EMT biomarkers and collagen Ⅲ were determined in uc.290 overexpressed or silenced epithelial colon cells (HT29).

RESULTS

Uc.290, TGF-β1 and collagen Ⅲ were overexpressed, and EMT was prominent in chronic active UC. Uc.290 level had a positive correlation with modified Mayo score in chronic active UC. TGF-β1 and collagen Ⅲ were overexpressed, and EMT was prominent in uc.290 overexpressed HT29 cells.

CONCLUSIONS

Uc.290 was overexpressed in chronic active UC and might promote intestinal fibrosis by TGF-β1/EMT/collagen Ⅲ pathway.

Activation of autophagy promotes the inhibitory effect of curcumin analog EF-24 against MDA-MB-231 cancer cells

Breast cancer is the leading cause of cancer deaths in women worldwide. EF-24, an analog of curcumin, has been shown to possess promising anticancer effects. However, the underlying mechanism remains elusive. In the present study, the inhibitory effect of EF-24 against one breast cancer cell line, MDA-MB-231, and its anti-migration ability were assessed by MTT, wound healing, and Transwell assay. Furthermore, we found that EF-24 could induce initiation of autophagy as evidenced by fluorescence and electron microscope observation. EF-24 also induced mitochondrial apoptosis in MDA-MB-231 cells as detected by Hoechst 33342 staining, flow cytometry analysis, and western blot analysis. In addition, the early autophagy inhibitor 3-MA could reduce the cleavage of PARP protein and protect cells from EF-24-induced apoptosis, while the autophagy inducer (rapamycin) could enhance the anticancer effect of EF-24 in MDA-MB-231 cells, which suggest that EF-24 induces crosstalk between autophagy and apoptosis, which herein participate in the antiproliferative effect of EF-24 in breast cancer cells. Moreover, removal of EF-24-activated ROS with NAC significantly reversed migration ability of MDA-MB-231 cells, indicating that EF-24 exerted an inhibitory effect through a ROS-mediating pathway. These results will help to elucidate the antitumor mechanism of curcumin analogs and to explore future potential clinical applications.

Inhibition of autophagic flux by the curcumin analog EF-24 and its antiproliferative effect on MCF-7 cancer cells

5-Bis[(2-fluorophenyl)methylene]-4-piperidinone (EF-24) is a curcumin analog, which was identified for its physiochemical stability and diverse pharmacological functions. In the present study, EF-24 was added to the breast cancer cell line MCF-7 and its cellular effects were characterized. The results indicated that EF-24 possessed antiproliferative and antimigratory activities on MCF-7 cells as determined by MTT assay, wound healing, and transwell assay, respectively. In addition, the autophagosomal vesicles could be detected by acridine orange staining and electron microscope analysis in EF-24-treated cells. Conversion of LC3-I to LC3-II was also investigated following EF-24 treatment of the cells. However, the expression analysis of p62 and LC3 revealed that EF-24 could inhibit autophagic flux in MCF-7 cells. Confocal microscopy suggested that EF-24 could inhibit the degradation of autophagic vesicles by blocking the fusion of autophagosomes with lysosomes. EF-24 could also induce apoptosis of MCF-7 cells as determined by Hoechst 33342 staining, flow cytometry analysis, and western blot analysis. Moreover, treatment of the cells with the autophagy inhibitor 3-MA enhanced the PARP1 cleavage of EF-24-treated MCF-7 cells, which indicated the crosstalk between autophagy and apoptosis in breast cancer cells. Additional investigation of EF-24 should be performed in future studies to assess its antiproliferation and antimigratory effects on MCF-7 cells. However, the current results provide a solid foundation for the potential in vivo anticancer activity of this compound.

Curcumin and Its Analogs in Non-Small Cell Lung Cancer Treatment: Challenges and Expectations

Researchers have made crucial advances in understanding the pathogenesis and therapeutics of non-small cell lung cancer (NSCLC), improving our understanding of lung tumor biology and progression. Although the survival of NSCLC patients has improved due to chemoradiotherapy, targeted therapy, and immunotherapy, overall NSCLC recovery and survival rates remain low. Thus, there is an urgent need for the continued development of novel NSCLC drugs or combination therapies with less toxicity. Although the anticancer effectiveness of curcumin (Cur) and some Cur analogs has been reported in many studies, the results of clinical trials have been inconsistent. Therefore, in this review, we collected the latest related reports about the anti-NSCLC mechanisms of Cur, its analogs, and Cur in combination with other chemotherapeutic agents via the Pubmed database (accessed on 18 June 2022). Furthermore, we speculated on the interplay of Cur and various molecular targets relevant to NSCLC with discovery studio and collected clinical trials of Cur against NSCLC to clarify the role of Cur and its analogs in NSCLC treatment. Despite their challenges, Cur/Cur analogs may serve as promising therapeutic agents or adjuvants for lung carcinoma treatment.

Antibacterial and Anticancer Activities of Pleurocidin-Amide, a Potent Marine Antimicrobial Peptide Derived from Winter Flounder, Pleuronectes americanus

The extensive use of conventional antibiotics has led to the growing emergence of many resistant strains of pathogenic bacteria. Evidence suggests that cationic antimicrobial peptides (AMPs) have the greatest potential to serve as traditional antibiotic substitutes. Recent studies have also reported that certain AMPs have selective toxicity toward various types of cancer cells. The electrostatic attraction between the negatively charged membrane components and AMPs is believed to play a crucial role in the disruption of bacterial and cancer cell membranes. In the current study, we used a potent AMP called Pleurocidin (Ple) derived from winter flounder Pleuronectes americanus and its C-terminal-amidated derivative Pleurocidin-amide (Ple-a), and evaluated their antibacterial and anticancer activities. Our results indicated that both Ple and Ple-a exhibited significant antibacterial activity against a broad spectrum of Gram-positive and Gram-negative bacteria, especially marine pathogens, with MIC values ranging from 0.25 to 32 μg/mL. These peptides are also potent against several multidrug-resistant (MDR) bacterial strains, with MIC values ranging from 2 to 256 μg/mL. When used in combination with certain antibiotics, they exhibited a synergistic effect against MDR E. coli. Ple and Ple-a also showed notable cytotoxicity toward various cancer cell lines, with IC₅₀ values ranging from 11 to 340 μM, while normal mouse fibroblast 3T3 cells were less susceptible to these peptides. Ple-a was then selected to study its anticancer mechanism toward A549 human lung adenocarcinoma cells. Western blot analysis and confocal microscopy showed that Ple-a could inhibit autophagy of A549 cells, and induce apoptosis 48 h after treatment. Our findings provided support for the future application of Ple-a as potential therapeutic agent for bacterial infections and cancer treatment.

Targeting autophagy in ethnomedicine against human diseases

ETHNOPHARMACOLOGICAL RELEVANCE

In the past five years, ethnopharmacy-based drugs have been increasingly used in clinical practice. It has been reported that hundreds of ethnopharmacy-based drugs can modulate autophagy to regulate physiological and pathological processes, and ethnomedicines also have certain therapeutic effects on illnesses, revealing the important roles of these medicines in regulating autophagy and treating diseases.

AIM OF THE STUDY

This study reviews the regulatory effects of natural products on autophagy in recent years, and discusses their pharmacological effects and clinical applications in the process of diseases. It provides a preliminary literature basis and reference for the research of plant drugs in the regulation of autophagy.

MATERIALS AND METHODS

A comprehensive systematic review in the fields of relationship between autophagy and ethnomedicine in treating diseases from PubMed electronic database was performed. Information was obtained from documentary sources.

RESULTS

We recorded some illnesses associated with autophagy, then classified them into different categories reasonably. Based on the uses of these substances in different researches of diseases, a total of 80 active ingredients or compound preparations of natural drugs were searched. The autophagy mechanisms of these substances in the treatments of divers diseases have been summarized for the first time, we also looked forward to the clinical application of some of them.

CONCLUSIONS

Autophagy plays a key function in lots of illnesses, the regulation of autophagy has become one of the important means to prevent and treat these diseases. About 80 compounds and preparations involved in this review have been proved to have therapeutic effects on related diseases through the mechanism of autophagy. Experiments in vivo and in vitro showed that these compounds and preparations could treat these diseases by regulating autophagy. The typical natural products curcumin and tripterine have powerful roles in regulating autophagy and show good and diversified curative effects.

Recent Advances in Curcumin Treated Non-Small Cell Lung Cancers: An Impetus of Pleiotropic Traits and Nanocarrier Aided Delive ry

Characterized by the abysmal 18% five year survival chances, non-small cell lung cancers (NSCLCs) claim more than half of their sufferers within the first year of being diagnosed. Advances in biomedical engineering and molecular characterization have reduced the NSCLC diagnosis via timid screening of altered gene expressions and impaired cellular responses. While targeted chemotherapy remains a major option for NSCLCs complications, delayed diagnosis, and concurrent multi-drug resistance remain potent hurdles in regaining normalcy, ultimately resulting in relapse. Curcumin administration presents a benign resolve herein, via simultaneous interception of distinctly expressed pathological markers through its pleiotropic attributes and enhanced tumor cell internalization of chemotherapeutic drugs. Studies on NSCLC cell lines and related xenograft models have revealed a consistent decline in tumor progression owing to enhanced chemotherapeutics cellular internalization via co-delivery with curcumin. This presents an optimum readiness for screening the corresponding effectiveness in clinical subjects. Curcumin is delivered to NSCLC cells either (i) alone, (ii) in stoichiometrically optimal combination with chemotherapeutic drugs, (iii) through nanocarriers, and (iv) nanocarrier co-delivered curcumin and chemotherapeutic drugs. Nanocarriers protect the encapsulated drug from accidental and non-specific spillage. A unanimous trait of all nanocarriers is their moderate drug-interactions, whereby native structural expressions are not tampered. With such insights, this article focuses on the implicit NSCLC curative mechanisms viz-a-viz, free curcumin, nanocarrier delivered curcumin, curcumin + chemotherapeutic drug and nanocarrier assisted curcumin + chemotherapeutic drug delivery.

Antiproliferative effect and autophagy induction of curcumin derivative ZYX02-Na on the human lung cancer cells A549

At present, a large number of curcumin derivatives had been produced and identified aiming to replace the curcumin in view of its low bioavailability and stability. Here, a novel curcumin derivative ZYX02-Na was first used to reduce the cell viability of human non-small cell lung cells A549, which was confirmed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometry and Western blot analysis showed that ZYX02-Na could lead to cell cycle arrest in G0/G1 phase, which demonstrated that ZYX02-Na inhibited the proliferation of A549 cells. Furthermore, the AMPK/mTOR/4E-BP1 signaling pathway was activated in ZYX02-Na-treated A549 cells. Besides, wounding healing and transwell experiments showed that ZYX02-Na could also inhibited the migration ability of A549 cells. Moreover, we also found that ZYX02-Na could induce autophagy of A549 cells by acridine orange staining, GFP-LC3 subcellular localization observation and Western blotting analysis, respectively. In short, our current studies indicated that ZYX02-Na possessed the antiproliferation effect and autophagy induction on A549 cells, while in vivo anticancer study of ZYX02-Na needs to be done in future.

Polyphenol-Mediated Autophagy in Cancer: Evidence of In Vitro and In Vivo Studies

One of the hallmarks of cellular transformation is the altered mechanism of cell death. There are three main types of cell death, characterized by different morphological and biochemical features, namely apoptosis (type I), autophagic cell death (type II) and necrosis (type III). Autophagy, or self-eating, is a tightly regulated process involved in stress responses, and it is a lysosomal degradation process. The role of autophagy in cancer is controversial and has been associated with both the induction and the inhibition of tumor growth. Autophagy can exert tumor suppression through the degradation of oncogenic proteins, suppression of inflammation, chronic tissue damage and ultimately by preventing mutations and genetic instability. On the other hand, tumor cells activate autophagy for survival in cellular stress conditions. Thus, autophagy modulation could represent a promising therapeutic strategy for cancer. Several studies have shown that polyphenols, natural compounds found in foods and beverages of plant origin, can efficiently modulate autophagy in several types of cancer. In this review, we summarize the current knowledge on the effects of polyphenols on autophagy, highlighting the conceptual benefits or drawbacks and subtle cell-specific effects of polyphenols for envisioning future therapies employing polyphenols as chemoadjuvants.

Versatile role of curcumin and its derivatives in lung cancer therapy

Lung cancer is a main cause of death all over the world with a high incidence rate. Metastasis into neighboring and distant tissues as well as resistance of cancer cells to chemotherapy demand novel strategies in lung cancer therapy. Curcumin is a naturally occurring nutraceutical compound derived from Curcuma longa (turmeric) that has great pharmacological effects, such as anti-inflammatory, neuroprotective, and antidiabetic. The excellent antitumor activity of curcumin has led to its extensive application in the treatment of various cancers. In the present review, we describe the antitumor activity of curcumin against lung cancer. Curcumin affects different molecular pathways such as vascular endothelial growth factors, nuclear factor-κB (NF-κB), mammalian target of rapamycin, PI3/Akt, microRNAs, and long noncoding RNAs in treatment of lung cancer. Curcumin also can induce autophagy, apoptosis, and cell cycle arrest to reduce the viability and proliferation of lung cancer cells. Notably, curcumin supplementation sensitizes cancer cells to chemotherapy and enhances chemotherapy-mediated apoptosis. Curcumin can elevate the efficacy of radiotherapy in lung cancer therapy by targeting various signaling pathways, such as epidermal growth factor receptor and NF-κB. Curcumin-loaded nanocarriers enhance the bioavailability, cellular uptake, and antitumor activity of curcumin. The aforementioned effects are comprehensively discussed in the current review to further direct studies for applying curcumin in lung cancer therapy.

Resveratrol suppresses melanoma growth by promoting autophagy through inhibiting the PI3K/AKT/mTOR signaling pathway

Resveratrol (RV) is a natural polyphenolic phytoalexin derived from peanuts, red grape skins and red wine, and has been demonstrated to alleviate multiple types of malignancies. However, how RV achieves this in melanoma is unknown. The aim of present study was to investigate the role of RV in melanoma, using Cell Counting Kit-8, flow cytometry and western blot analysis. RV inhibited melanoma cell viability, migration and invasion counteracting melanoma progression. In addition, proteins associated with autophagy, including Beclin 1 and microtubule-associated protein 1A/1B-light chain 3 (LC3)-II/I, were upregulated, whereas p62 expression was downregulated in RV-treated cells. The number of LC3+ puncta, which can be applied to represent autophagosome formation, increased following RV treatment, suggesting that RV may trigger autophagy in melanoma cells. Treatment with the autophagy inhibitor, 3-methyladenine, reversed the RV-dependent inhibition of viability, migration and invasion of melanoma cells. RV treatment also reduced the ratios of phosphorylated (p)-AKT/AKT and p-mTOR/mTOR in melanoma cells. In conclusion, these findings suggested that RV may inhibit the viability and migration of melanoma cells through inhibiting the AKT/mTOR pathway, thus triggering autophagy. This indicated that RV may serve as an innovative therapeutic for melanoma treatment.