Interplay between apoptosis and autophagy in colorectal cancer

Molecular Mechanism of Radioresponsiveness in Colorectal Cancer: A Systematic Review

Background/Objectives: Colorectal cancer (CRC) is the third most diagnosed cancer globally. Radiotherapy is a common treatment strategy for patients but factors such as gene expressions and molecular mechanism effects may affect tumor radioresponse. The aim of this review is to systematically identify genes suggested to have molecular mechanism effects on the radioresponsiveness of CRC patients. Methods: By following the PRISMA guidelines, a comprehensive literature search was conducted on Pubmed, EMBASE and Cochrane Library. After exclusion and inclusion criteria sorting and critical appraisal for study quality, data were extracted from seven studies. A gene set analysis was conducted on reported genes. Results: From the seven studies, 56 genes were found to have an effect on CRC radioresponsiveness. Gene set analysis show that out of these 56 genes, 24 genes have roles in pathways which could affect cancer radioresponse. These are AKT1, APC, ATM, BRAF, CDKN2A, CTNNB1, EGFR, ERBB2, FLT3, KRAS, MET, mTOR, MYC, NFKB1, KRAS, PDGFRA, PIK3CA, PTEN, PTGS1, PTGS2, RAF1, RET, SMAD4 and TP53. The current project was conducted between the period May 2024 to August 2024. Conclusions: The current review systematically presented 56 genes which have been reported to be related to RT or CRT treatment effectiveness in rectal cancer patients. Gene set analysis shows that nearly half of the genes were involved in apoptosis, DNA damage response and repair, inflammation and cancer metabolism molecular pathways that could affect cancer radioresponse. The gene cohort identified in this study may be used as a foundation for future works focusing on the molecular mechanism of specific pathways contributing to the radioresponse of CRC.

IL-8 and PI3K pathway influence the susceptibility of TRAIL-sensitive colorectal cancer cells to TRAIL-induced cell death

BACKGROUND

Tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is an apoptosis inducer that exhibits an ideal therapeutic safety profile with less adverse effects than conventional chemotherapy. However, the occurrence of TRAIL resistance has been reported in various cancers including colorectal cancer (CRC). Substantial efforts have been channelled towards managing TRAIL resistance including identifying molecular targets. Interleukins (ILs) have been recently shown to play critical roles in modulating TRAIL sensitivity in cancer cells.

METHODS AND RESULTS

This study investigated the roles of two ILs, IL-8 and IL⍺, in TRAIL resistance in CRC. TRAIL-resistant HT-29 and TRAIL-sensitive HCT 116 cells, were treated with human recombinant IL-8 and IL-1⍺. The results indicated that treatment with IL-8 (2.5 ng/mL) significantly protected TRAIL-sensitive HCT 116 cells from TRAIL-induced cell death (p < 0.05). However, IL-1⍺ did not play a role in modulating CRC cells' responses to TRAIL. Data from RT-qPCR and Western blotting revealed the molecular regulations of IL-8 on TRAIL decoy receptor genes (OPG) and autophagy-related genes (BECN1 and LC3B) expression. The activation of the phosphoinositide 3-kinase (PI3K) pathway was shown to counteract TRAIL-induced cell death. By inhibiting its activation with wortmannin, the protective role of IL-8 against TRAIL treatment was reversed, suggesting the involvement of the PI3K pathway.

CONCLUSION

Collectively, findings from this study identified the role of IL-8 and PI3K in modulating CRC cells' sensitivity to TRAIL. Further validation of these two potential molecular targets is warranted to overcome TRAIL resistance in CRC.

2D and 3D in vitro angiogenesis assays highlight different aspects of angiogenesis

In angiogenesis research, scientists need to carefully select appropriate in vitro models to test their hypotheses to minimize the risk for false negative or false positive study results. In this study, we investigate molecular differences between simple two-dimensional and more complex three-dimensional angiogenesis assays and compare them to in vivo data from cancer-associated angiogenesis using an unbiased transcriptomic analysis. Human umbilical vein endothelial cells were treated with VEGF in 2D wound healing and proliferation assays and the 3D spheroid sprouting assay. VEGF-induced transcriptomic shifts were assessed in both settings by bulk RNA sequencing. Immunocytochemistry was used for protein detection. The data was linked to the transcriptomic profile of vascular endothelial cells from a single cell RNA sequencing dataset of various cancer tissue compared to adjacent healthy tissue control. VEGF induced a more diverse transcriptomic shift in vascular endothelial cells in a 3D experimental setting (767 differentially expressed genes) compared to the 2D settings (167 differentially expressed genes). Particularly, VEGF-induced changes in cell-matrix interaction, tip cell formation, and glycolysis were pronounced in the 3D spheroid sprouting experiments. Immunocytochemistry for VCAM1 and CD34 confirmed enhanced expression in response to VEGF-treatment in 3D settings. In vivo, vascular endothelial cells within various cancer tissue were characterized by strong transcriptomic changes in cell-matrix interaction and glycolysis similar to the 3D setting. Consequently, 3D assays may better address certain key aspects of angiogenesis in comparison to fast and scalable 2D assays. This should be taken into consideration within the context of each research question.

The synergistic effect of oxaliplatin and punicalagin on colon cancer cells Caco-2 death

Objectives

The objectives of the study are to investigate the synergistic effect of oxaliplatin (oxa) and punicalagin (pun) on the death of colon cancer cells (Caco-2) by apoptosis and autophagy.

Methods

The effects of the combined treatments (5 μM oxa + 50 μM pun, 5 μM oxa + 75 μM pun, 20 μM oxa + 50 μM pun, and 5 μM oxa + 75 μM pun) were compared with untreated Caco2 cells (control) or cells treated with oxa alone. Apoptosis was detected using an Annex in V FITC flow cytometry assay and poly (ADP-ribose) polymerase cleavage by western blotting. Light chain 3 was detected by western blotting as an autophagy marker.

Results

The combined treatments significantly increased the number of apoptotic cells in comparison to untreated cells or cells treated with oxa alone. By contrast, the combined treatments had no significant effect on autophagy.

Conclusion

The combined treatment significantly promoted cell death through apoptosis while maintaining a basal level of autophagy.

Expression and Clinical Significance of IRE1-XBP1s, p62, and Caspase-3 in Colorectal Cancer Patients

Background

Three main cell signaling pathways including the endoplasmic reticulum stress (ERS) response, autophagy, and apoptosis play critical roles in both cell survival and death. They were found to crosstalk with one another during tumorigenesis and cancer progression. This study aimed to investigate the expression of the spliced form of X-box binding protein 1 (XBP1s), p62, and caspase-3, as the essential biomarkers of ERS, autophagy, and apoptosis in patients with colorectal cancer (CRC), as well as the correlation between their expression and clinicopathological data.

Methods

This retrospective study was conducted on formalin-fixed paraffin-embedded (FFPE) blocks, which were collected from patients and their tumor margins, from the tumor bank of Imam Khomeini Hospital (Tehran, Iran) from 2017 to 2019. Tissue microarray (TMA) was used to measure the XBP1s, p62, and caspase-3 biomarkers. Data were analyzed using SPSS software version 20, and P≤0.05 was considered statistically significant.

Results

Evaluating the total of 91 patients, a significant relationship was found between XBP1s expression and TNM stage (P=0.003), primary tumor (pT) (P=0.054), and the degree of differentiation (P=0.006); and between caspase-3 with pT (P=0.004), and lymphovascular invasion (P=0.02). However, no significant correlation was found between p62 and clinicopathological data. Furthermore, a positive relationship between XBP1s and p62 was confirmed (correlation coefficient: 22.2% and P=0.05).

Conclusion

Our findings indicated that XBP1s could be considered as a target for therapy in personalized medicine.

Scoparone induces autophagic cell death via the PAK1/AKT axis in colorectal cancer

Colorectal cancer (CRC) is one of most common malignancies worldwide, yet curative therapy remains a clinical challenge. Here, we demonstrate that scoparone (Scop), a traditional Chinese medicine monomer, inhibits the growth of CRC cells both in vitro and in vivo. Further studies found that Scop treatment induces complete autophagic flux in CRC cells, while inhibition of autophagy markedly represses the antiproliferative activities of Scop, suggesting an antitumour property of Scop-induced autophagy in CRC. Mechanistically, Scop induced autophagy initiation by reducing P21-activated kinase 1 (PAK1) expression and subsequently repressing the AKT/mTOR signaling pathway. Collectively, our study suggests that Scop is a potential anti-CRC therapeutic option and provides an underlying molecular mechanism for its antitumour effect in CRC.

Role of the ER-induced UPR pathway, apoptosis, and autophagy in colorectal cancer

When large amounts of misfolded or unfolded proteins accumulate in the endoplasmic reticulum (ER) in response to stress, a process called unfolded protein response (UPR) is activated. The disruption of this process leads to many diseases including diabetes, neurodegenerative diseases, and many cancers. In the process of UPR in response to stress and unfolded proteins, specific signaling pathways are induced in the endoplasmic reticulum and subsequently transmitted to the nucleus and cytoplasm, causing homeostasis and restoring the cell's normal condition with reducing protein translation and synthesis. The UPR response followed by stress enhancement balances cell survival with death, therefore in this condition cells decide either to survive or have the path of apoptosis ahead. However, in some cases, this balance is disturbed and the UPR pathway is chronically activated or not activated and the cell conditions lead to cancer. This study aimed to briefly investigate the association between ER stress, UPR, apoptosis, and autophagy in colorectal cancer (CRC). Moreover, in current study, we will try to demonstrate canonical ways and methods for the treatment of CRC cells with attenuated ER stress.

Potential of curcumin and niacin-loaded targeted chitosan coated liposomes to activate autophagy in hepatocellular carcinoma cells: An in vitro evaluation in HePG2 cell line

The objective of this study is to activate autophagy in hepatocellular carcinoma for the enhancement of its cellular degradation. Liposomes incorporated chitosan in the core used to improve the stability of lecithin and increase the niacin loading efficiency. Additionally, curcumin as a hydrophobic molecule entrapped into liposomal layers and used as a face layer to minimize the release of niacin in physiological pH 7.2. Folic acid-conjugated chitosan was used to facilitate the delivery of liposomes into a specific location of cancer cells. TEM, UV Visible spectrophotometer, and FTIR confirmed the successful liposomal formation and good encapsulation efficiency. Based on the cellular proliferation of HePG2, the results revealed that there was a significant inhibition of growth rate of HePG2 after 48 h of incubation at a concentration of 100 μg/mL by 91 % ± 1 %, P ≤ 0.002 (pure niacin), 55 % ± 3 %, P ≤ 0.001 (pure curcumin), 83 % ± 1.5 %, P ≤ 0.001 (niacin NPs), and 51 % ± 1.5 % P ≤ 0.0001 (curcumin-niacin NPs) of relative to the control. Increasingly, The expression of mRNA of mTOR was significantly increased by 0.72 ± 0.08 P ≤ 0.001, 1 ± 0.1, 0. P ≤ 0.001, 5 ± 0.07 P ≤ 0.01, and 1.3 ± 0.02 P ≤ 0.001 folds) in pure niacin, pure curcumin, niacin NPs and curcumin -niacin NPs, respectively, relative to the control with an expression of 0.3 ± 0.08. Additionally, the expression of p62 mRNA was significantly increased by 0.92 ± 0.07 P ≤ 0.05, 1.7 ± 0.07 P ≤ 0.0001, 0.72 ± 0.08 P ≤ 0.5, and 2.1 ± 0.1 P ≤ 0.0001 folds relative to that of the control with an expression of 0.72 ± 0.08. The results highlight the efficient therapies of biomaterials derived from natural sources that can be used in cancer therapies instead of traditional chemotherapies.

Sertaconazole nitrate targets IDO1 and regulates the MAPK signaling pathway to induce autophagy and apoptosis in CRC cells

Colorectal cancer (CRC) has become the third most frequently occurring malignant tumor worldwide. It is vital to identify novel, effective targeted treatments while considering side effects and drug resistance in the clinic. Recently, the tryptophan-metabolizing enzyme indole-2, 3-dioxygenase 1 (IDO1) has been widely reported to be overexpressed in CRC, indicating that blocking IDO1 with small-molecule inhibitors may be a promising approach to CRC treatment. In this study, the antifungal drug sertaconazole nitrate (STZ) was repurposed and showed antitumor activity, and therefore, its anticancer effect was further investigated in CRC cells. The SwissTargetPrediction analysis indicated that STZ binding to IDO1 was significantly and highly probable, and STZ was found to downregulate IDO1 in CRC cells in a dose-dependent manner. STZ exhibited considerable antiproliferative activity and induced apoptosis and autophagy in HCT116 and RKO cells. Moreover, based on an RNA-seq analysis, STZ was shown to regulate signal transducer and activator of transcription 3 (STAT3) and the mitogen-activated protein kinase (MAPK) signaling pathways. We discovered that STZ suppressed tumor growth in an HCT116 nude mouse xenograft tumor model without causing evident cytotoxicity. In conclusion, our results reveal that STZ induces antitumor effects in CRC by inhibiting IDO1-modulated autophagy and apoptosis, providing a clue for repurposing STZ as a novel and potentially effective candidate medication for the future treatment of CRC.

Autophagy: Dual roles and perspective for clinical treatment of colorectal cancer

Colorectal cancer (CRC) raises concerns to people because of its high recurrence and metastasis rate, diagnosis challenges, and poor prognosis. Various studies have shown the association of altered autophagy with tumorigenesis, tumor-stroma interactions, and resistance to cancer therapy in CRC. Autophagy is a highly conserved cytosolic catabolic process in eukaryotes that plays distinct roles in CRC occurrence and progression. In early tumorigenesis, autophagy may inhibit tumor growth through diverse mechanisms, whereas it exhibits a tumor promoting function in CRC progression. This different functions of autophagy in CRC occurrence and progression make developing therapies targeting autophagy complicated. In this review, we discuss the classification and process of autophagy as well as its dual roles in CRC, functions in the tumor microenvironment, cross-talk with apoptosis, and potential usefulness as a CRC therapeutic target.

The potential effect of Schisandrin-B combination with panitumumab in wild-type and mutant colorectal cancer cell lines: Role of apoptosis and autophagy

Panitumumab is an approved monoclonal antibody for the treatment of colorectal cancer (CRC); however, mutations in EGFR signaling pathway resulted in poor response. Schisandrin-B (Sch-B) is a phytochemical that was suggested to protect against inflammation, oxidative stress, and cell proliferation. The present study aimed to investigate the potential effect of Sch-B on panitumumab-induced cytotoxicity in wild-type Caco-2, and mutant HCT-116 and HT-29 CRC cell lines, and the possible underlying mechanisms. CRC cell lines were treated with panitumumab, Sch-B, and their combination. The cytotoxic effect of drugs was determined by MTT assay. The apoptotic potential was assessed in-vitro by DNA fragmentation and caspase-3 activity. Additionally, autophagy was investigated via microscopic detection of autophagosomes and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) measurement of Beclin-1, Rubicon, LC3-II, and Bcl-2 expression. The drug pair enhanced panitumumab cytotoxicity in all CRC cell lines where IC50 of panitumumab was decreased in Caco-2 cell line. Apoptosis was induced through caspase-3 activation, DNA fragmentation, and Bcl-2 downregulation. Caco-2 cell line treated with panitumumab showed stained acidic vesicular organelles, contrariwise, all cell lines treated with Sch-B or the drug pair displayed green fluorescence indicating the lack of autophagosomes. qRT-PCR revealed the downregulation of LC3-II in all CRC cell lines, Rubicon in mutant cell lines, and Beclin-1 in HT-29 cell line only. Sch-B at 6.5 µM promoted panitumumab-induced apoptotic cell death, in-vitro, via caspase-3 activation and Bcl-2 downregulation, rather than autophagic cell death. This novel combination therapy against CRC, allows the reduction of panitumumab dose to guard against its adverse effects.

Anti-leukemic effect of menthol, a peppermint compound, on induction of apoptosis and autophagy

Background

Menthol, a natural compound in peppermint leaves, has several biological activities, including antioxidant, anti-inflammatory, antiviral, antibacterial and anticancer properties. This study revealed the anti-leukemic effects and its underlying mechanisms of the menthol related apoptosis signaling pathway and autophagy in both NB4 and Molt-4 leukemic cell lines.

Methods

Both leukemic cells were treated with menthol in various concentration. Cell viability was assessed using MTT assay, whereas apoptosis and autophagy were analyzed by flow cytometry using Annexin V-FITC/PI and anti-LC3/FITC antibodies staining, respectively. Apoptotic and autophagic related gene and protein expression were detected using RT-qPCR and western blot analysis, respectively. Moreover, STITCH database was used to predicts the interaction between menthol and proposed proteins.

Results

Menthol significantly decreased cell viability in NB4 and Molt-4 cell lines in dose dependent manner. In combination of menthol and daunorubicin, synergistic cytotoxic effects were observed in leukemic cells. However, there was a minimal effect found on normal, peripheral blood mononuclear cells (PBMCs). Moreover, menthol significantly induced apoptosis induction via upregulation of caspase-3, BAX, p53 and downregulation of MDM2 mRNA expression. Autophagy was also induced by menthol through upregulating ATG3 and downregulating mTOR mRNA expression. For protein expression, menthol significantly increased caspase-3 whereas decreased mTOR in both leukemic cells. Conclusions. These results suggest that menthol exhibits cytotoxic activities by inhibition of cell proliferation, induction of apoptosis and autophagy through activating the caspase cascade, altering BAX and p53/MDM2, and regulating autophagy via the ATG3/mTOR signaling pathway.

KLF5-mediated aquaporin 3 activated autophagy to facilitate cisplatin resistance of gastric cancer

BACKGROUND

Resistance to chemotherapeutic drugs limits the control of gastric cancer (GC) development. The study intended to probe into the mechanism of aquaporin 3 (AQP3) on the chemoresistance of GC.

METHODS

Cisplatin (CDDP)-resistant cells were constructed. Parental AGS and HGC-27 cells and their respective CDDP-resistant cells were transfected with AQP3 overexpression plasmid, AQP3 short hairpin RNA (sh-AQP3) and sh-Kruppel-like factor 5 (shKLF5). The expressions of AQP3 and factors related to autophagy (LC3 I, LC3 II, Atg5, Beclin-1, p62)/epithelial-mesenchymal transition (EMT; E-cadherin and snail) were assessed by Western blot and qRT-PCR. Cell counting kit-8 assay was adopted to test cell viability and half maximal inhibitory concentration (IC 50) was determined. Transwell assay was used for the examination of cell migration and invasion. The regulatory relationship of AQP3 and KLF5 was tested by chromatin immunoprecipitation (ChIP) and dual luciferase reporter assays.

RESULTS

AQP3 was highly-expressed in GC cells and its level was even higher in CDDP-resistant GC cells. AQP3 silencing inhibited viability, autophagy and EMT in CDDP-resistant GC cells, while AQP3 overexpression had the opposite effect. KLF5 positively modulated AQP3 in GC cells resistant to CDDP. KLF5 knockdown reversed AQP3-induced autophagy, viability, migration, invasion and EMT in CDDP-resistant GC cells.

CONCLUSION

KLF5-modulated AQP3 activated autophagy to facilitate the resistance of GC to CDDP.

Role of autophagy in cholangiocarcinoma: An autophagy-based treatment strategy

Cholangiocarcinomas (CCAs) are diverse biliary epithelial tumours involving the intrahepatic, perihilar and distal parts of the biliary tree. The three entirely variable entities have distinct epidemiology, molecular characteristics, prognosis and strategy for clinical management. However, many cholangiocarcinoma tumor-cells appear to be resistant to current chemotherapeutic agents. The role of autophagy and the therapeutic value of autophagy-based therapy are largely unknown in CCA. The multistep nature of autophagy offers a plethora of regulation points, which are prone to be deregulated and cause different human diseases, including cancer. However, it offers multiple targetable points for designing novel therapeutic strategies. Tumor cells have evolved to use autophagy as an adaptive mechanism for survival under stressful conditions such as energy imbalance and hypoxic region of tumors within the tumor microenvironment, but also to increase invasiveness and resistance to chemotherapy. The purpose of this review is to summarize the current knowledge regarding the interplay between autophagy and cholangiocarcinogenesis, together with some preclinical studies with agents that modulate autophagy in order to induce tumor cell death. Altogether, a combinatorial strategy, which comprises the current anti-cancer agents and autophagy modulators, would represent a positive CCA patient approach.

Dietary Polyphenols: Promising Adjuvants for Colorectal Cancer Therapies

Simple Summary

Colorectal cancer is a leading cause of death worldwide. Despite the development of novel surgical and therapeutic strategies, 50% of patients relapse after treatment. Therapy failure, due to low efficacy, adverse effects and drug resistance, is thus a major concern. The idea of combining standard therapy with non-toxic bioactive natural compounds is a recent topic in cancer research and aims to increase the efficacy of current antitumor therapies while reducing drug toxicity and adverse effects. In recent years, several studies have explored the capacity of polyphenols, dietary bioactive compounds enriched in fruit and vegetables, to act as adjuvants to improve colorectal cancer therapy. In the present review, we discuss these studies, highlighting the mechanisms underlying the adjuvant effect, and bring out the potential of this novel therapeutic approach as well as the critical issues related to clinical application.

Abstract

Colorectal cancer (CRC) is a major cancer type and a leading cause of death worldwide. Despite advances in therapeutic management, the current medical treatments are not sufficient to control metastatic disease. Treatment-related adverse effects and drug resistance strongly contribute to therapy failure and tumor recurrence. Combination therapy, involving cytotoxic treatments and non-toxic natural compounds, is arousing great interest as a promising more effective and safer alternative. Polyphenols, a heterogeneous group of bioactive dietary compounds mainly found in fruit and vegetables, have received great attention for their capacity to modulate various molecular pathways active in cancer cells and to affect host anticancer response. This review provides a summary of the most recent (i.e., since 2016) preclinical and clinical studies using polyphenols as adjuvants for CRC therapies. These studies highlight the beneficial effects of dietary polyphenols in combination with cytotoxic drugs or irradiation on both therapy outcome and drug resistance. Despite substantial preclinical evidence, data from a few pilot clinical trials are available to date with promising but still inconclusive results. Larger randomized controlled studies and polyphenol formulations with improved bioavailability are needed to translate the research progress into clinical applications and definitively prove the added value of these molecules in CRC management.

Rauwolfia vomitoria Extract Represses Colorectal Cancer Cell Autophagy and Promotes Apoptosis

BACKGROUND

Colorectal cancer (CRC) is one of the most frequent digestive tract tumors in the world with an increasing incidence. Currently, surgical resection and chemotherapy are the main therapeutic options; however, their effects are limited by various adverse reactions. Rauwolfia vomitoria extract (Rau) has been shown to repress the progression of multiple human cancers; however, whether Rau plays a role in CRC remains undetermined.

METHODS

Influences of Rau treatment on HCT-116 and LoVo cells were estimated via MTT and colony formation experiments. Flow cytometry analysis was adopted to evaluate the apoptosis rate of HCT-116 and LoVo cells. Apoptosis-related proteins (Bcl-2, Bax, and caspase-3) and autophagy-related proteins (LC3 and P62) were assessed by Western blotting. Effects of Rau on autophagy of HCT-116 and LoVo cell were evaluated through GFP-LC3 analysis. In vivo xenograft tumor assay was conducted to further examine the role of Rau in CRC tumor growth.

RESULTS

Rau remarkably repressed HCT-116 and LoVo cell viability and promoted HCT-116 and LoVo cell apoptosis in vitro in a dose-dependent manner. Rau increased the expression of caspase-3 and Bax and decreased the expression of Bcl-2 in HCT-116 and LoVo cells. Moreover, Rau was demonstrated to decrease the LC3||/LC3| ratio and increase the level of P62 in HCT-116 and LoVo cells. In addition, we found that Rau repressed xenograft tumor growth and also repressed autophagy in vivo.

CONCLUSION

Our findings revealed that Rau repressed CRC cell viability and autophagy in vitro and in vivo, suggesting that Rau might be a potent therapeutic agent of CRC.

A Bioactive Compound from Sanguisorba officinalis L. Inhibits Cell Proliferation and Induces Cell Death in 5-Fluorouracil-Sensitive/Resistant Colorectal Cancer Cells

Colorectal cancer (CRC) is one of the most common cancer in the world. The first line chemotherapeutic agent, 5-fluorouracil (5-FU), plays a predominant role in the clinical treatment of CRC. However, with the wide use of 5-FU, more and more CRC patients have been obtaining drug resistance to 5-FU, which leads to a large amount of treatment failures. One of the effective strategies to overcome this obstacle is to find bioactive natural products from traditional medicine. In our previous work, Sanguisorba officinalis L. was found to exert a strong anti-proliferative activity against 5-FU-senstive/resistant CRC cells. Therefore, several compounds were isolated from this herb and screened for their anti-CRC effects to find promising compounds. Among them, a triterpenoid compound named 3β-[(α-l-arabinopyranosyl) oxy]-urs-12,18(19)-dien-28-oic acid β-d-glucopyranosyl ester (AGE), showed strong activity against both 5-FU-senstive and resistant CRC cells. In order to further study the mechanism of AGE on CRC cells, flow cytometer analysis, mitochondrial membrane potential (MMP) measurement, Western blotting, and RT-PCR assays were performed. Results demonstrated that AGE induced cell death by apoptosis pathway and autophagy, and inhibited cell proliferation via cell cycle arrest in G0-G1 phase mediated by Wnt signaling pathway. Therefore, AGE may be a potential bioactive compound for CRC treatment in clinic.

Colossolactone-G synergizes the anticancer properties of 5-fluorouracil and gemcitabine against colorectal cancer cells

Several terpenoids were isolated from Ganoderma colossum with potential chemotherapeutic properties against different solid tumor cells. Herein, we further assessed the potential chemomodulatory effects of colossolactone-G to gemcitabine (GCB) and 5-fluorouracil (5-FU) against colorectal cancer cells. Colossolactone-G induced moderate cell killing effects against both HT-29 and HCT-116 cells, with IC₅₀'s of 90.5 ± 1.7 µM and 22.3 ± 3.9 µM, respectively. Equitoxic combination demonstrated a synergistic effect between colossolactone-G and GCB, or 5-FU with combination indices ranging from 0.22 to 0.67. Both GCB and 5-FU induced moderate cell cycle arrest at G₀/G₁-phase and S-phase. Despite colossolactone-G's lack of influence on cell cycle distribution, it significantly potentiated GCB- and 5-FU-induced cell cycle arrest. Similarly, colossolactone-G treatment alone did not induce pronounced apoptosis in both cell lines. However, 5-FU and GCB induced significant apoptosis which was further potentiated via combination with colossolactone-G. Furthermore, colossolactone-G significantly increased autophagic cell death response in both HCT-116 and HT-29 cells and potentiated 5-FU- and GCB-induced autophagic cell death. The influence of colossolactone-G alone or in combination with GCB or 5-FU on the apoptosis and autophagy were confirmed by qPCR analysis for the expression of several key apoptosis and autophagy genes such as, TRAIL, TP53INP1, BNIP3, hp62, ATG5, ATG7, Lamp2A and the golden standard for autophagy (LC3-II). In conclusion, a synergistic effect in terms of anticancer properties was observed when colossolactone-G was combined with 5-FU and GCB, where it influenced both apoptosis and autophagic cell death mechanisms.

Role of Stress-Survival Pathways and Transcriptomic Alterations in Progression of Colorectal Cancer: A Health Disparities Perspective

Every year, more than a million individuals are diagnosed with colorectal cancer (CRC) across the world. Certain lifestyle and genetic factors are known to drive the high incidence and mortality rates in some groups of individuals. The presence of enormous amounts of reactive oxygen species is implicated for the on-set and carcinogenesis, and oxidant scavengers are thought to be important in CRC therapy. In this review, we focus on the ethnicity-based CRC disparities in the U.S., the negative effects of oxidative stress and apoptosis, and gene regulation in CRC carcinogenesis. We also highlight the use of antioxidants for CRC treatment, along with screening for certain regulatory genetic elements and oxidative stress indicators as potential biomarkers to determine the CRC risk and progression.

Western influenced lifestyle and Kv2.1 association as predicted biomarkers for Tunisian colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third most diagnosed malignancy worldwide. The global burden is expected to increase along with ongoing westernized behaviors and lifestyle. The etiology of CRC remains elusive and most likely combines environmental and genetic factors. The Kv2.1 potassium channel encoded by KCNB1 plays a collection of roles in malignancy of cancer and may be a key factor of CRC susceptibility. Our study provides baseline association between Tunisian CRC and interactions between KCNB1 variants and lifestyle factors.

METHODS

A case-control study involving 300 CRC patients, and 300 controls was conducted Patients were carefully phenotyped and followed till the end of study. KCNB1 genotyping was confirmed by Sanger sequencing. Bivariate and multivariable logistic regression analyses were used to assess the clinical status, lifestyle and study polymorphisms association with CRC.

RESULTS

We noted significant gender association with CRC occurrence. Moreover, CRC risk increases with high meat and fat consumption, alcohol use and physical activity (PA). Carriage of rs1051296 A/G and both rs11468831 ins/del and del/del genotypes (p < 0.001) were significantly associated with CRC risk. Analysis according to gender reveals correlation of rs1051295 A/G, rs11468831 non ins/ins (p = 0.01) with CRC susceptibility regardless of patients' gender while rs3331 T/C (p = 0.012) was associated with females. Stratification study according to malignancy site; Rectal Cancer (RC) and Colon Cancer (CC), reveals increasing RC risk by gender and high meat and fat consumption, alcohol use and PA. However, additional association with high brine consumption was noted for CC. The rs1051295 A/G (p = 0.01) was associated with RC risk. Increased CC risk was associated with carriage of rs1051295 A/G, rs11168831 (del/del) and (ins/del) genotypes.

CONCLUSION

The risk of CRC increases with modifiable factors by Western influences on Tunisian lifestyle such as alcohol use, high fat consumption and possibly inadequate intake of vegetables. In addition, KCNB1 polymorphisms also markedly influence CRC susceptibility. Our study establishes key elements of a baseline characterization of clinical state, Western influenced lifestyle and KCNB1 variants associated with Tunisian CRC.

Contrast effects of autophagy in the treatment of bladder cancer

Bladder cancer is a disease that negatively affects patients' quality of life, but treatment options have remained unchanged for a long time. Although promising results have been achieved with current bladder cancer treatments, cancer recurrence, progression, and therapy resistance are the most severe problems preventing the efficiency of bladder cancer treatments. Autophagy refers to an evolutionarily conserved catabolic process in which proteins, damaged organelles, and cytoplasmic components are degraded by lysosomal enzymes. Autophagy regulates the therapeutic response to the chemotherapy drugs, thus determining the effect of therapy on cancer cells. Autophagy is a stress-induced cell survival mechanism and its excessive stimulation can cause resistance of tumor cells to therapeutic agents. Depending on the conditions, an increase in autophagy may cause treatment resistance or autophagic cell death, and it is related to important anti-cancer mechanisms, such as apoptosis. Therefore, understanding the roles of autophagy under different conditions is important for designing effective anti-cancer agents. The dual role of autophagy in cancer has attracted considerable attention in respect of bladder cancer treatment. In this review, we summarize the basic characteristics of autophagy, including its mechanisms, regulation, and functions, and we present examples from current studies concerning the dual role of autophagy in bladder cancer progression and therapy.

AMPK/mTOR/ULK1 Axis-Mediated Pathway Participates in Apoptosis and Autophagy Induction by Oridonin in Colon Cancer DLD-1 Cells

BACKGROUND

Oridonin has been demonstrated to exert strong antitumor activities in various types of human cancers. Our previous study established that oridonin induced the apoptosis of and exerted an inhibitory effect on colon cancer cells in vitro and in vivo. However, the mechanisms behind the antitumor effects of oridonin on colorectal cancer are not clearly known. This study explored whether autophagy was involved in antitumorigenesis effects caused by the usage of oridonin in colon cancer and examined whether the AMPK/mTOR/ULK1 signaling pathway was involved in this process.

METHODS

Cell viability was determined using CCK-8 assay. The distribution of cell apoptosis was evaluated using flow cytometry. RT-PCR and Western blotting analysis were conducted to identify the key target genes and proteins involved in the AMPK/mTOR cascade. AMPK siRNA was used to disturb AMPK expression. A DLD-1 cell orthotopic transplantation tumor model was established to explore the anti-cancer effects in vivo.

RESULTS

Oridonin exhibited a suppressive effect on DLD-1 cells in a concentration- and time-dependent manner. Additionally, in a dose-dependent manner, oridonin induced cell apoptosis via inducing the protein expression levels of cleaved caspase-3, cleaved PARP and stimulated autophagy by increasing protein expression levels of Becin1, LC3-II, decreasing protein expression levels of LC3-I, p62, which were respectively attenuated and elevated by autophagy inhibitor 3-MA. Furthermore, oridonin upregulated the expression level of p-AMPK and downregulated the expression levels of p-mTOR, p-ULK1 in the DLD-1 cells in a dose-dependent manner. Moreover, knockdown of AMPK by a specific siRNA reversed the expression levels of proteins involved in the AMPK/mTOR pathway, autophagy and apoptosis. In addition, outcomes from the in vivo experiments also showed that oridonin treatment significantly repressed tumorigenic growth of DLD-1 cells without any side effects, which was accompanied by the upregulation of p-AMPK, LC3-II, active caspase-3 protein expression levels and the downregulation of p-mTOR and p-ULK1 protein expression levels.

CONCLUSION

This study demonstrated that oridonin induced apoptosis and autophagy of colon cancer DLD-1 cells via regulating the AMPK/mTOR/ULK1 pathway, which indicated that oridonin may be used as a novel therapeutic intervention for patients with colorectal cancer.

Hsa-miR-425-5p promotes tumor growth and metastasis by activating the CTNND1-mediated β-catenin pathway and EMT in colorectal cancer

Colorectal cancer (CRC) is a common malignancy with high mortality. However, the roles of miR-425-5p and its underlying mechanism in CRC remain unknown. Here, RT-qPCR confirmed that miR-425-5p expression was increased by miR-425-5p mimic in SW480 cells and decreased by miR-425-5p inhibitor in LOVO cells. CCK-8, flow cytometry, wound healing and transwell assays revealed that the increased miR-425-5p promoted cell viability, cell cycle entry, migration and invasion in CRC. Besides, miR-425-5p overexpression induced epithelial-mesenchymal transition (EMT) with upregulation of Fibronectin, N-cadherin, Vimentin, and downregulation of E-cadherin. Moreover, miR-425-5p overexpression induced c-myc, Cyclin D1 and MMP7 levels, and promoted β-catenin translocation to the nucleus. Knockdown of miR-425-5p exerted opposite effects. Luciferase reporter assay indicated that miR-425-5p directly targeted CTNND1. Overexpression of miR-425-5p repressed CTNND1 expression at mRNA and protein levels. Silencing of CTNND1 had the inhibitory effect of miR-425-5p inhibitor on cell proliferation, migration, invasion, EMT, and the activation of β-catenin signaling pathway. Furthermore, miR-425-5p promoted tumor growth and metastasis in vivo. In conclusion, miR-425-5p may promote tumorigenesis and metastasis through activating CTNND1-mediated β-catenin pathway, which may provide therapeutic targets for human CRC.

Regulation of Autophagy by Non-Steroidal Anti-Inflammatory Drugs in Cancer

Cancer is the leading cause of death, placing a substantial global health burden. The development of the most effective treatment regimen is the unmet clinical need for cancer. Inflammation plays a role in tumorigenesis and progression, and anti-inflammation may be a promising option for cancer management and prevention. Emerging studies have shown that non-steroidal anti-inflammatory drugs (NSAIDs) display anticarcinogenic and chemopreventive properties through the regulation of autophagy in certain types of cancer. In this review, we summarize the pharmacological functions and side effects of NSAIDs as chemotherapeutic agents, and focus on its mode of action on autophagy regulation, which increases our knowledge of NSAIDs and cancer-related inflammation, and contributes to a putative addition of NSAIDs in the chemoprevention and treatment of cancer.

KCNB1 gene polymorphisms and related indel as predictor biomarkers of treatment response for colorectal cancer - toward a personalized medicine

The KCNB1 gene variants were differentially associated with cancers. However, their association with colorectal cancer has not yet been explored. We investigated the contribution of the KCNB1 gene variants rs3331, rs1051295, and indel (insertion/deletion) rs11468831 Polymorphism as predictors of the treatment response in colorectal cancer patients. A retrospective study, which involved 291 Tunisian colorectal cancer patients (aged 60.0 ± 13.1 years), who were stratified into responder and non-responder groups, according to TNM stages and their responsiveness to chemotherapy based on fluorouracil. KCNB1 genotyping was performed with amplification-refractory mutation system-polymerase chain reaction, and was confirmed by Sanger sequencing. Sex-specific response was found and colorectal cancer females are less likely to achieve a positive response during the chemotherapy strategy, compared to males. Weight and body mass index, tumor size, and tumor localization are considered as predictive factors to treatment responsiveness. Carriage of rs11468831 Ins allele was significantly associated with successful therapy achievement (p adjusted < 0.001). Stratification of colorectal cancer patients' response according to tumor localization and TNM stages reveals negative association of rs3331 Major allele to treatment response among the patients with advanced cancer stages (subgroup G2). The presence of rs3331 (homozygous minor) C/C genotype was positively associated with decline in carcino-embryonic antigen (p = 0.043) and CA19-9 (p = 0.014) serum levels. On the other hand, the presence of rs1051295 (homozygous minor) A/A genotype was correlated with marked decline in CA19-9 serum levels. KCNB1 haplotype did not reveal any association between haplotypes and treatment response. The results obtained suggest that gender-specific strategies for screening treatment and prevention protocols as well as KCNB1 variants may constitute an effective model for ongoing personalization medicine.

Autophagy-related Proteins as a Prognostic Factor of Patients With Colorectal Cancer

Supplemental Digital Content is available in the text.

Autophagy plays a dual role in tumorigenesis. In the initial stages, it promotes cell survival and suppresses carcinogenesis, whereas in cancer development, it induces cancer cell survival. In this study, we investigate the role of autophagy as a protective or tumor suppressor mechanism in colorectal cancer (CRC) cell lines and evaluate its role as a potential biomarker in human tumor samples.

Camellia nitidissima Chi Extract Potentiates the Sensitivity of Gastric Cancer Cells to Paclitaxel via the Induction of Autophagy and Apoptosis

Background

Camellia nitidissima Chi (CNC) has been applied as a traditional folk medicine for the effective treatment of various diseases. However, there is little research regarding the mechanism of CNC on pharmaceutical function including anticancer effect.

Materials and methods

JHC-4 is a n-butanol extract from CNC. The anti-proliferation effect was evaluated by MTT assays. Monodansylcadaverine (MDC) staining, Western blotting and autophagy inhibitors (CQ and BafA1) were applied to determine whether JHC-4 induced autophagy. The synergistic anticancer effect was evaluated by MTT assays, flow cytometry, Western blotting and autophagy inhibitors. Western blotting was used to explore the influence of PI3K/Akt/mTOR signaling pathway induced by drug treatment.

Results

JHC-4 caused significant growth inhibition and induced autophagy in human gastric cancer cells. Moreover, JHC-4 as an autophagy agonist synergistically potentiated the sensitivity of gastric cancer cells to paclitaxel. Meanwhile, JHC-4 could significantly enhance the growth inhibition effect of paclitaxel by the induction of autophagy and apoptosis. Finally, we demonstrated that the PI3K/Akt/mTOR signaling pathway was involved in the synergistic anti-proliferation effect of JHC-4 and paclitaxel.

Conclusion

All these data indicated that JHC-4 was a novel autophagy inducer when combination with paclitaxel for gastric cancer, which provided the scientific evidence for the use of this Chinese traditional medicine against cancer.

Wheat Bran for Colon Cancer Prevention: The Synergy between Phytochemical Alkylresorcinol C21 and Intestinal Microbial Metabolite Butyrate

There is convincing evidence that consuming whole grains (WGs) may decrease the risk of colorectal cancer (CRC). Wheat bran (WB) is a rich source of dietary fiber and phytochemicals with health-promoting properties. However, the active components especially the interaction between different components in WG wheat have not been fully explored. Here, we investigated whether one of the major WB phytochemicals, alkylresorcinol (AR) C21, and the major active intestinal microbial metabolite of fiber, butyrate, could synergistically suppress human colon cancer cells. Our results demonstrated for the first time that the combination of C21 and butyrate synergistically inhibited the growth of human colon cancer cells and induced apoptosis. Further mechanistic studies demonstrated that the cotreatment of C21 and butyrate induced significant up-regulations in cleaved Poly(ADP-ribose) polymerase (PARP), cleaved caspase 3, p53 upregulated modulator of apoptosis (PUMA), cytochrome C, lipid-conjugated membrane-bound form of microtubule-associated protein 1A/1B-light chain 3 (LC3-II), and C/EBP homologous protein (CHOP) expressions, indicating the synergistic anticancer effects of C21 and butyrate were associated with induction of apoptosis, autophagy, and ER stress pathways. Notably, the C21 concentrations in the large intestinal tract of mice treated with human relevant doses of C21, were from 0.86 to 1.78 μmol/g, suggesting the C21 doses used in vitro may be achievable after daily WG wheat intake. These results provide novel insights into the dietary prevention of CRC regarding the potential interaction of bioactive WG wheat phytochemicals and the microbial metabolites of fiber.

Soyasapogenol B Attenuates Laryngeal Carcinoma Progression through Inducing Apoptotic and Autophagic Cell Death

Soyasapogenol B (Soy B), a constituent of soybean, has been shown to exhibit antitumor activities against different types of cancers. However, to our knowledge, no studies so far have investigated the effect of Soy B in human laryngeal carcinoma. This study, therefore, aimed to determine the effect of Soy B in human laryngeal carcinoma cell lines HeP-2 and TU212 and to elucidate the possible underlying mechanisms by which Soy B can induce its antitumor effects. The results showed that Soy B effectively attenuated the cell growth by causing G0/G1 phase cell cycle arrest in laryngeal carcinoma cell lines. Moreover, the percentage of apoptotic and autophagic cells dramatically increased upon exposure to Soy B. Western blotting results confirmed that Soy B can alter the expression levels of established markers of apoptosis and autophagy. Interestingly, both apoptosis inhibitor (ZVAD-fmk) and autophagy inhibitor (3-MA) could partially reverse the effect of Soy B, while blocking autophagy did not cause obvious alteration in the percentage of apoptotic cells. Similarly, in vivo studies validated that Soy B could effectively reduce the size of the tumor and induce apoptosis and autophagy in tumor tissues. Collectively, these results suggested that Soy B can exert anticancer activities against laryngeal carcinoma through inducing apoptotic and autophagic cell death. Our study highlighted the potential role of Soy B as a chemotherapeutic agent for laryngeal carcinoma. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:1851-1858, 2020. © 2019 American Association for Anatomy.

MCT1 relieves osimertinib-induced CRC suppression by promoting autophagy through the LKB1/AMPK signaling

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers worldwide. Development of novel chemotherapeutics is still required to enable successful treatment and improve survival for CRC patients. Here, we found that osimertinib (OSI) exhibits potent anti-CRC effects by inducing apoptosis, independent of its selective inhibitory activity targeting the EGFR T790M mutation. Intriguingly, OSI treatment triggers autophagic flux in CRC cells. Inhibition of autophagy markedly augments OSI-induced apoptosis and growth inhibition in CRC cells, suggesting a protective role of autophagy in response to OSI treatment. Mechanistically, OSI upregulates the expression of monocarboxylate transporter 1 (MCT1) and subsequently activates LKB1/AMPK signaling, leading to autophagy induction in CRC cells. Notably, OSI significantly exaggerates the sensitivity of CRC cells to the first-line drugs 5-fluorouracil or oxaliplatin. Taken together, our study unravels a novel mechanism of OSI-mediated protective autophagy involving MCT1/LKB1/AMPK signaling, and suggests the use of OSI as a potential agent for clinical CRC treatment.

Grape seed procyanidin B2 promotes the autophagy and apoptosis in colorectal cancer cells via regulating PI3K/Akt signaling pathway

Aim: Colorectal cancer (CRC) is a major malignancy in China, which is the critical risk of people health. Many natural herbs extracts have been found to exhibit good therapeutic effect on CRC. Our previous study found that grape seed procyanidins B2 (PB2) would induce CRC cell death. However, the molecular mechanism underlying its anti-tumor effect on CRC remains unclear. Thereby, this study aimed to investigate the anti-tumor mechanism of PB2 on CRC.

Methods: CCK-8, western blotting, flow cytometry, qRT-PCR and animal study were used in the current study.

Results: The in vitro and in vivo data demonstrated that PB2 could promote the apoptosis of CRC cells in a dose-dependent manner, which was significantly reversed by caspase 3 inhibitor. Meanwhile, PB2 dose-dependently induced autophagy in CRC cells, which was markedly attenuated by autophagy inhibitor 3-MA. In addition, PB2 dose-dependently inhibited the expressions of p-PI3K, p-Akt and p-mTOR in the cells.

Conclusion: PB2 dose-dependently induced apoptosis and autophagy in CRC cells via downregulation of PI3K/Akt pathway. This study provided the experimental basis for further development of PB2 as a new effective anticancer drug for the patients with CRC.

The Interplay of Autophagy and Tumor Microenvironment in Colorectal Cancer-Ways of Enhancing Immunotherapy Action

Autophagy as a primary homeostatic and catabolic process is responsible for the degradation and recycling of proteins and cellular components. The mechanism of autophagy has a crucial role in several cellular functions and its dysregulation is associated with tumorigenesis, tumor-stroma interactions, and resistance to cancer therapy. A growing body of evidence suggests that autophagy is also a key regulator of the tumor microenvironment and cellular immune response in different types of cancer, including colorectal cancer (CRC). Furthermore, autophagy is responsible for initiating the immune response especially when it precedes cell death. However, the role of autophagy in CRC and the tumor microenvironment remains controversial. In this review, we identify the role of autophagy in tumor microenvironment regulation and the specific mechanism by which autophagy is implicated in immune responses during CRC tumorigenesis and the context of anticancer therapy.

α-hederin induces autophagic cell death in colorectal cancer cells through reactive oxygen species dependent AMPK/mTOR signaling pathway activation

α-hederin, a monodesmosidic triterpenoid saponin, had previously demonstrated strong anticancer effects. In the current study, the pharmacological mechanism of autophagic cell death induced by α-hederin was investigated in human colorectal cancer cells. First, through cell counting kit-8 and colony formation assays, it was demonstrated that α-hederin could inhibit the proliferation of HCT116 and HCT8 cell. Results of flow cytometry using fluorescein isothiocyanate Annexin V/propidium iodide and Hoechst 33258 staining indicated that α-hederin could induce apoptosis. Western blotting demonstrated that α-hederin could activate mitochondrial apoptosis signal pathway. Then, using light chain 3 lentiviral and electron microscope assay, it was demonstrated that α-hederin could induce autophagy in colorectal cancer cells. In addition, immunohistochemistry results from in vivo experiments also demonstrated that α-hederin could induce autophagy. AMP-activated protein kinase (AMPK)/mechanistic target of rapamycin (mTOR) signaling was demonstrated to be activated by α-hederin, which could be blocked by reactive oxygen species (ROS) inhibitor NAC. Furthermore, NAC could inhibit apoptosis and autophagy induced by α-hederin. Finally, 3-MA (autophagy inhibitor) reduced the inhibition of α-hederin on cell activity, but it had no significant effect on apoptosis. In conclusion, α-hederin triggered apoptosis through ROS-activated mitochondrial signaling pathway and autophagic cell death through ROS dependent AMPK/mTOR signaling pathway activation in colorectal cancer cells.

Non‑covalent proteasome inhibitor PI‑1840 induces apoptosis and autophagy in osteosarcoma cells

Osteosarcoma (OS) is the predominant form of primary bone malignancy in children and adolescents. Although the combination of chemotherapy and modified surgical therapy leads to marked improvements in the survival rate, the therapeutic outcomes remain unsatisfactory. Therefore, the identification of novel drugs with higher efficacy and fewer side‑effects is urgently required. Proteasome inhibitors have been approved by the Food and Drug Administration (FDA) for the treatment of certain cancers, although none of them are directed against OS. Non‑covalent proteasome inhibitors, such as PI‑1840, are superior to covalent ones in numerous respects in view of their chemical structure; however, to date, no studies have been published on the effects of non‑covalent proteasome inhibitors on OS cells. In the present study, the antineoplastic effects of PI‑1840 were systematically evaluated in the OS cell lines, MG‑63 and U2‑OS. Cell viability and morphological changes were assessed by Cell Counting Kit‑8 (CCK‑8) and live/dead assays. The cell cycle was analyzed using flow cytometry (FCM) and western blot analysis (assessing the levels of the proteins p21, p27, and the tyrosine kinase, WEE1). The extent of cell apoptosis and autophagy were assessed by FCM, western blot analysis [of the apoptosis‑associated proteins, microtubule‑associated protein 1 light chain 3 α (LC3) and Beclin1], and mRFP‑GFP‑LC3 adenovirus transfection assay. Transwell and wound healing assays, and western blot analysis of the matrix metalloproteinases (MMPs)2 and 9 were performed to preliminarily evaluate the migration and invasion capability of the cells. In the present study, our results revealed that PI‑1840 inhibited the proliferation of OS cells and induced apoptosis, partly due to attenuation of the nuclear factor‑κB (NF‑κB) pathway. In addition, PI‑1840‑induced autophagy was detected, and inhibiting the autophagy of the OS cells led to an increase in the survival rate of the U2‑OS cells rather than of the MG‑63 cells. Furthermore, PI‑1840 attenuated the migration and invasion capabilities of the OS cells. In conclusion, the present study revealed PI‑1840 to be a promising drug for the treatment of OS.

Selected Aspects of Chemoresistance Mechanisms in Colorectal Carcinoma-A Focus on Epithelial-to-Mesenchymal Transition, Autophagy, and Apoptosis

Chemoresistance has been found in all malignant tumors including colorectal carcinoma (CRC). Nowadays chemoresistance is understood as a major reason for therapy failure, with consequent tumor growth and spreading leading ultimately to the patient's premature death. The chemotherapy-related resistance of malignant colonocytes may be manifested in diverse mechanisms that may exist both prior to the onset of the therapy or after it. The ultimate function of this chemoresistance is to ensure the survival of malignant cells through continuing adaptation within an organism, therefore, the nature and spectrum of cell-survival strategies in CRC represent a highly significant target of scientific inquiry. Among these survival strategies employed by CRC cells, three unique but significantly linked phenomena stand out-epithelial-to-mesenchymal transition (EMT), autophagy, and cell death. In this mini-review, current knowledge concerning all three mechanisms including their emergence, timeline, regulation, and mutual relationships will be presented and discussed.

Upgraded role of autophagy in colorectal carcinomas

Autophagy is a basic catabolic process closely associated with degradation of cellular components. The role of autophagy in colorectal cancer (CRC) remains controversial. The mechanism of autophagy has been identified as protecting mechanism against tumorigenesis by isolation of damaged organelles or as cytoprotective provides energy in hypoxic regions of CRC tumors. Mutations in proto-oncogenes, such as RAS and BRAF, have been associated with autophagy initiation through signaling pathways of BRAF/MEK/ERK and PI3K/AKT/mTOR. A combination therapy of chemotherapeutic agents and autophagy inhibitors such as hydroxychloroquine or immunotherapy might represent a major step that could be evaluated as a putative novel therapeutic strategy in CRC patients.

Sodium butyrate induces autophagy in colorectal cancer cells through LKB1/AMPK signaling

Butyrate is produced by the fermentation of undigested dietary fibers and acts as the promising candidate for cancer treatment. However, the mechanism underlying sodium butyrate (NaB)-induced autophagy in colorectal cancer is not yet completely understood. The expressions of LC3-II protein and mRNA were detected by western blot and quantitative RT-PCR in colorectal cancer (CRC) cell lines HCT-116 and HT-29, respectively. Autolysosome formation was observed by transmission electron microscope. AMPK and LKB1 were inhibited by chemical inhibitor or siRNAs and confirmed by western blot. NaB elevated the protein and mRNA expressions of LC3 in a dose-dependent manner. NaB treatment increased the formation of autolysosome and expression of phosphorylated liver kinase B1 (LKB1), AMP-activated protein kinase (AMPK), and acetyl-CoA carboxylase (ACC). Treatment with compound C (an inhibitor of AMPK) and siRNA-mediated knockdown of AMPK and LKB1 significantly attenuated NaB-induced autophagy in CRC cells. Collectively, these findings indicated that LKB1 and AMPK are critical for NaB-mediated autophagy and may act as the novel targets for colorectal cancer therapy in the future.

Identifying autophagy gene-associated module biomarkers through construction and analysis of an autophagy-mediated ceRNA‑ceRNA interaction network in colorectal cancer

Autophagy is crucial in cellular homeostasis and has been implicated in the development of malignant tumors. However, the regulatory function of autophagy in cancer remains to be fully elucidated. In the present study, the autophagy-mediated competing endogenous RNA (ceRNA)-ceRNA interaction networks in colorectal cancer (CRC) were constructed by integrating systematically expression profiles of long non-coding RNAs and mRNAs. It was found that a large proportion of autophagy genes were inclined to target hub nodes, including a fraction of autophagy genes, by comparing with other genes within ceRNA networks, and showed preferential interaction with themselves. The present study also revealed that autophagy genes may be used as prognostic markers for cancer therapy. A risk score model based on multivariable Cox regression analysis was then used to capture novel biomarkers in connection with lncRNA for the prognosis of CRC. These biomarkers were confirmed in the test dataset and an additional independent dataset. Furthermore, the prognostic value of biomarkers is independent of conventional clinical factors. These results provide improved understanding of autophagy-mediated ceRNA regulatory mechanisms in CRC and provide novel potential molecular therapeutic targets for the diagnosis and treatment of CRC.

Coronarin D induces reactive oxygen species-mediated cell death in human nasopharyngeal cancer cells through inhibition of p38 MAPK and activation of JNK

Background and Purpose

Nasopharyngeal carcinoma (NPC) belongs to squamous cell carcinoma that occurs in the epithelial lining of the nasopharynx. Because of the anatomical position close to the cervical lymph node, some patients have a distant metastasis at the time of diagnosis that leads to treatment failure. Although early stages have a high curability and excellent prognosis, advanced NPC urgently requires new drugs developed to reinforce the effectiveness of therapy without noticeable side effects.

Experimental approach

Coronarin D (CD), a natural product extracted from the rhizomes of Hedychium coronarium, has been reported to possess anticancer potential. The aim of the present study was to determine the anticancer activity of CD and further elucidate the underlying molecular mechanisms.

Key Results

In this study, we first demonstrated that CD potently suppressed cell viability in various NPC cell lines. Treatment of cells with CD induced G2/M arrest, apoptosis, and autophagy. Further studies showed that CD increased the production of reactive oxygen species and subsequently activated both autophagy and apoptosis. Moreover, we found that CD-induced activation of p38 and JNK constituted major mechanisms involved in the apoptosis and autophagy triggered by CD. In particular, inhibition of autophagy could strengthen the cytotoxicity of CD, implying that autophagy seems to play a valuable survival and protective role in cancer cells.

Conclusions & Implications

These findings provide a promise for the use of CD in combination with autophagy inhibitors for treatment of human NPC cell lines.