Molecular Mechanism of Resistance to Chemotherapy in Gastric Cancers, the Role of Autophagy

CACNA1H restrains chemotherapy resistance in ovarian clear cell carcinoma cells by repressing autophagy

Ovarian clear cell carcinoma (OCCC) is a subtype of ovarian cancer and is highly malignant with high chemoresistance. CACNA1H is pivotal in tumor development. However, the role of CACNA1H in the acquisition process of chemotherapeutic resistance in OCCC cells is rarely reported. Therefore, this study aimed to explore the role of CACNA1H in chemotherapy resistance of OCCC cells and its related mechanism. Based on bioinformatics analysis, we found that CACNA1H was downregulated in chemoresistant OCCC patients compared to chemosensitive OCCC patients. Comparing DDP-resistant and sensitive OCCC cell lines, the resistant strain showed lower CACNA1H mRNA expression. CACNA1H expression was associated with calcium signaling pathways in chemoresistant OCCC patients. CACNA1H mRNA expression was significantly downregulated in OCCC cells compared to normal ovarian epithelial cells. When CACNA1H was overexpressed, intracellular Ca2+ concentration and protein levels of p-CaMKII and p-Akt were significantly upregulated, while protein levels of LC3-II/LC3-I and Beclin1 were downregulated, indicating a repression of autophagy. The rescue experiment revealed that CACNA1H overexpression in drug-resistant OCCC cells reduced autophagy-induced DDP resistance via CaMKII/Akt signaling. Overall, CACNA1H increased intracellular Ca2+ concentration and activated CaMKII/Akt signaling pathway in OCCC, thereby repressing autophagy to maintain the sensitivity of OCCC cells to DDP.

Asiaticoside promoted ferroptosis and suppressed immune escape in gastric cancer cells by downregulating the Wnt/β-catenin pathway

BACKGROUND

Our previous study has revealed that asiaticoside (AC) promotes endoplasmic reticulum stress and antagonizes proliferation and migration of gastric cancer (GC) via miR-635/HMGA1 axis. However, the effect and mechanism of AC on other progressions of GC, such as ferroptosis and immune escape, are still unknown.

METHODS

AGS and HGC27 cells were incubated with 1, 2 and 4 μM of AC for 24 h. Mice xenografted with AGS cells were intragastrically injected with AC. The effect and mechanism of AC on GC were determined by the measurement of the ferrous iron level, the ROS level and the glutathione peroxidase (GSH) content, flow cytometry, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry and western blotting assays.

RESULTS

AC increased the Fe2+ level and the ROS level, but decreased the expression of GPX4 and SLC7A11 and the GSH level. Besides, AC enhanced the percent of CD8+ T cells and the IFN-γ concentration, but reduced the PD-L1 expression and the IL-10 level. Mechanically, AC downregulated the relative levels of β-catenin, active-β-catenin, p-GSK3β/GSK3β, cyclin D1 and c-Myc in GC cells, which were rescued with the application of LiCl (an activator of Wnt/β-catenin pathway) in AGS cells. Moreover, activation of Wnt/β-catenin pathway by LiCl or the β-catenin overexpression inverted the effect of AC on ferroptosis and immune escape in GC cells. In vivo, AC treatment declined the tumor size and weight, the level of GPX4, SLC7A11, PD-L1 and IFN-γ, and the expression of Wnt/β-catenin pathway.

CONCLUSION

AC enhanced ferroptosis and repressed immune escape by downregulating the Wnt/β-catenin signaling in GC.

Nanotherapeutics targeting autophagy regulation for improved cancer therapy

The clinical efficacy of current cancer therapies falls short, and there is a pressing demand to integrate new targets with conventional therapies. Autophagy, a highly conserved self-degradation process, has received considerable attention as an emerging therapeutic target for cancer. With the rapid development of nanomedicine, nanomaterials have been widely utilized in cancer therapy due to their unrivaled delivery performance. Hence, considering the potential benefits of integrating autophagy and nanotechnology in cancer therapy, we outline the latest advances in autophagy-based nanotherapeutics. Based on a brief background related to autophagy and nanotherapeutics and their impact on tumor progression, the feasibility of autophagy-based nanotherapeutics for cancer treatment is demonstrated. Further, emerging nanotherapeutics developed to modulate autophagy are reviewed from the perspective of cell signaling pathways, including modulation of the mammalian target of rapamycin (mTOR) pathway, autophagy-related (ATG) and its complex expression, reactive oxygen species (ROS) and mitophagy, interference with autophagosome-lysosome fusion, and inhibition of hypoxia-mediated autophagy. In addition, combination therapies in which nano-autophagy modulation is combined with chemotherapy, phototherapy, and immunotherapy are also described. Finally, the prospects and challenges of autophagy-based nanotherapeutics for efficient cancer treatment are envisioned.

Inflammatory microenvironment in gastric premalignant lesions: implication and application

Gastric precancerous lesions (GPL) are a major health concern worldwide due to their potential to progress to gastric cancer (GC). Understanding the mechanism underlying the transformation from GPL to GC can provide a fresh insight for the early detection of GC. Although chronic inflammation is prevalent in the GPL, how the inflammatory microenvironment monitored the progression of GPL-to-GC are still elusive. Inflammation has been recognized as a key player in the progression of GPL. This review aims to provide an overview of the inflammatory microenvironment in GPL and its implications for disease progression and potential therapeutic applications. We discuss the involvement of inflammation in the progression of GPL, highlighting Helicobacter pylori (H. pylori) as a mediator for inflammatory microenvironment and a key driver to GC progression. We explore the role of immune cells in mediating the progression of GPL, and focus on the regulation of inflammatory molecules in this disease. Furthermore, we discuss the potential of targeting inflammatory pathways for GPL. There are currently no specific drugs for GPL treatment, but traditional Chinese Medicine (TCM) and natural antioxidants, known as antioxidant and anti-inflammatory properties, exhibit promising effects in suppressing or reversing the progression of GPL. Finally, the challenges and future perspectives in the field are proposed. Overall, this review highlights the central role of the inflammatory microenvironment in the progression of GPL, paving the way for innovative therapeutic approaches in the future.

Novel 2-substituted-quinoxaline analogs with potential antiproliferative activity against breast cancer: insights into cell cycle arrest, topoisomerase II, and EGFR activity

Breast cancer is a global health concern, with increasing disease burden and disparities in access to healthcare. Late diagnosis and limited treatment options in underserved areas contribute to poor outcomes. In response to this challenge, we developed a novel family of 2-substituted-quinoxaline analogues, combining coumarin and quinoxaline scaffolds known for their anticancer properties. Through a versatile synthetic approach, we designed, synthesized, and characterized a set of 2-substituted quinoxaline derivatives. The antiproliferative activity of the synthesized compounds was assessed toward the MCF-7 breast cancer cells. Our investigations showed that the synthesized compounds exhibit considerable antiproliferative activity toward MCF-7 cells. Notably, compound 3b, among examined compounds, displayed a superior inhibitory effect (IC50 = 1.85 ± 0.11 μM) toward the growth of MCF-7 cells compared to the conventional anticancer drug staurosporine (IC50 = 6.77 ± 0.41 μM) and showed minimal impact on normal cells (MCF-10A cell lines, IC50 = 33.7 ± 2.04 μM). Mechanistic studies revealed that compound 3b induced cell cycle arrest at the G1 transition and triggered apoptosis in MCF-7 cells, as evidenced by increasing the percentage of cells arrested in the G2/M and pre-G1 phases utilizing flow cytometric analysis and Annexin V-FITC/PI analysis. Moreover, compound 3b was found to substantially suppress topoisomerase enzyme activity in MCF-7 cells. Molecular modeling studies further supported the potential of compound 3b as a therapeutic candidate by demonstrating significant binding affinity to the active sites of both topoisomerase II and EGFR proteins. Taken together, the presented 2-substituted-quinoxaline analogues, especially compound 3b, show promise as potential candidates for the development of effective anti-breast cancer drugs.

Emetine, a small molecule natural product, displays potent anti-gastric cancer activity via regulation of multiple signaling pathways

BACKGROUND

Gastric cancer (GC) is a life-threatening malignant tumor with high incidence rate. Despite great progress, there are still many GC sufferers that cannot benefit from the existing anti-GC treatments. Therefore, it is still necessary to develop novel medicines against GC. Emetine, a natural small molecule isolated from Psychotria ipecacuanha, has been broadly used for medicinal purposes including cancer treatment. Here, we conducted a comprehensive study on the anti-GC effects of emetine and the related mechanisms of action.

METHODS

The cell viability was evaluated by MTT and colony formation assay. Cellular proliferation and apoptosis were analyzed by edu incorporation assay and Annexin V-PI staining, respectively. Moreover, wound healing assay and transwell invasion assay were conducted to detect cell migration and invasion after treatment with emetine. To elucidate the molecular mechanism involved in the anti-GC effects of emetine, RNA sequencing and functional enrichment analysis were carried out on MGC803 cells. Then, the western blot analysis was performed to further verify the anti-GC mechanism of emetine. In vivo anti-tumor efficacy of emetine was evaluated in the MGC803 xenograft model.

RESULTS

MTT and colony formation assay exhibited a strong potency of emetine against GC cell growth, with IC₅₀ values of 0.0497 μM and 0.0244 μM on MGC803 and HGC-27 cells, respectively. Further pharmacodynamic studies revealed that emetine restrained the growth of GC cells mainly via proliferation inhibition and apoptosis induction. Meanwhile, emetine also had the ability to block GC cell migration and invasion. The results of RNA sequencing and western blot showed that emetine acted through regulating multiple signaling pathways, including not only MAPKs and Wnt/β-catenin signaling axes, but also PI3K/AKT and Hippo/YAP signaling cascades that were not found in other tumor types. Notably, the antitumor efficacy of emetine could also be observed in MGC803 xenograft models.

CONCLUSION

Our data demonstrate that emetine is a promising lead compound and even a potential drug candidate for GC treatment, deserving further structural optimization and development.

Evaluating the Magnolol Anticancer Potential in MKN-45 Gastric Cancer Cells

Background and Objectives: Combination therapy improves the effect of chemotherapy on tumor cells. Magnolol, used in treating gastrointestinal disorders, has been shown to have anti-cancer properties. We investigated the synergistic effect of cisplatin and magnolol on the viability and maintenance of MKN-45 gastric cancer cells. Materials and Methods: The toxicity of magnolol and/or cisplatin was determined using the MTT technique. The trypan blue method was used to test magnolol and/or cisplatin's effect on MKN-45 cell growth. Crystal violet staining was used to assess the treated cells' tendency for colony formation. The expression of genes linked to apoptosis, cell cycle arrest, and cell migration was examined using the qPCR method. Results: According to MTT data, using magnolol and/or cisplatin significantly reduced cell viability. The ability of the treated cells to proliferate and form colonies was also reduced considerably. Magnolol and/or cisplatin treatment resulted in a considerable elevation in Bax expression. However, the level of Bcl2 expression was dramatically reduced. p21 and p53 expression levels were significantly increased in the treated cells, while MMP-9 expression was significantly reduced. Conclusions: These findings show that magnolol has a remarkable anti-tumor effect on MKN-45 cells. In combination with cisplatin, magnolol may be utilized to overcome cisplatin resistance in gastric cancer cells.

ERK inhibitor: A candidate enhancing therapeutic effects of conventional chemo-radiotherapy in esophageal squamous cell carcinoma

For patients with esophageal squamous cell carcinoma (ESCC), standard therapeutic methods (cisplatin and radiotherapy) have been found to be ineffective and severely toxic. Targeted therapy emerges as a promising solution for this dilemma. It has been reported that targeted therapies are applied alone or in combination with standard conventional therapies for the treatment of a variety of cancers. To the best of our knowledge, in patients with ESCC, the combinational methods containing standard therapy and ERK-targeted therapy have yet to be explored. To analyze the prognostic role of p-ERK in ESCC patients, the Kaplan-Meier analysis and Cox regression model were used. To assess the effects of ERK-targeted therapy (GDC0994) on ESCC cells, in vitro studies including CCK-8 assay, colony formation assay, and scratch wound healing assay were conducted. In addition, the changes in cell cycle distribution and apoptosis were analyzed by flow cytometry. Besides, to assess the efficacy of different therapies in vivo, the xenograft tumor models were established by subcutaneously inoculating tumor cells into the flank/leg of mice. In patients with ESCC, a strong correlation between the high expression level of p-ERK and the poor prognosis (p < 0.01, Log-Rank test) has been identified. By analyzing the results from CCK-8 and scratch wound healing assays, we demonstrated that the ERK inhibitor repressed the viability and migration of ESCC cells. In addition, following the treatment of GDC0994, the volumes of xenograft tumors significantly decreased (p < 0.001, one-way ANOVA). Furthermore, blocking the mitogen-activated protein kinase (MAPK/ERK) pathway enhanced the therapeutic efficacy of both cisplatin and radiotherapy (p < 0.05). These findings imply the role of p-ERK in the prognosis of ESCC patients and the therapeutic value of ERK inhibitors in ESCC.

Exosomal circ_0091741 promotes gastric cancer cell autophagy and chemoresistance via the miR-330-3p/TRIM14/Dvl2/Wnt/β-catenin axis

The importance of cancer cell-released exosomes in the treatment of various cancers has been well-characterized. The current study aims to examine the potential biological functions of gastric cancer (GC) cell-released exosomes delivering a novel circRNA circ_0091741 in GC and the underlying molecular mechanism. Expression of circ_0091741 was examined in the GC cells, (OXA)-resistant HGC-27 (HGC-27/OXA) cells, and isolated exosomes, after which its downstream miRNA was analyzed. The role and mechanism of the circ_0091741 transmitted by GC cells-derived exosomes in GC cell autophagy and chemoresistance were assessed using various molecular biological methods. A mouse tumor xenograft model was prepared to discern the effect of circ_0091741 on tumorigenesis in vivo. GC cells and their exosomes were characterized by upregulated circ_0091741 expression. circ_0091741 transferred by GC cell-derived exosomes induced the autophagy and OXA resistance of GC cells. circ_0091741 obstructed the binding of miR-330-3p to TRIM14 and increased the expression of TRIM14. TRIM14 could cause activation of the Wnt/β-catenin signaling pathway by stabilizing Dvl2. By this mechanism, the autophagy and OXA resistance of GC cells were augmented. In vivo assay unfolded that orthotopic implantation of exosomal circ_0091741 overexpressed GC cells into nude mice enhanced tumorigenesis. In conclusion, our study emphasized the promotive role of exosomal circ_0091741 in autophagy and chemoresistance of GC cells, thus laying the basis for the development of novel therapeutic targets for GC treatment.

Probe-Based Confocal Laser Endomicroscopy versus White-Light Endoscopy with Narrow-Band Imaging for Predicting and Collecting Residual Cancer Tissue in Patients with Gastric Cancer Receiving Chemotherapy

Simple Summary

Collecting appropriate gastric cancer (GC) tissues is critical for molecular biology research or the development of new target drugs for cases resistant to chemotherapy. Chemotherapy may reduce or alter the distribution of GC tissue on the surface, making the detection of GC tissue during upper endoscopy challenging. Our study showed that probe-based confocal laser endomicroscopy (pCLE) is superior to white-light endoscopy (WLE) with magnifying narrow-band imaging (M-NBI) in terms of accuracy for diagnosing residual cancer in GC patients receiving chemotherapy. pCLE might be considered when it is necessary to confirm the presence of residual cancer and get tissue samples from GC patients receiving chemotherapy.

Abstract

In cases of progression despite chemotherapy, collecting gastric cancer (GC) tissues might be helpful for molecular biology research or the development of new target drugs for treating cases that are refractory to chemotherapy. Chemotherapy, however, may reduce or alter the distribution of GC tissue on the surface, making the detection of GC tissue during upper endoscopy challenging. Probe-based confocal laser endomicroscopy (pCLE) is a new technology that enables histological diagnosis by magnifying the mucous membrane to a microscopic level. Here, we evaluated whether pCLE could increase the yield of endoscopic biopsy for GC compared to white-light endoscopy (WLE) with magnifying narrow-band imaging (M-NBI) in GC patients receiving chemotherapy with its powerful imaging technique. Patients underwent WLE/M-NBI and pCLE for the detection of residual GC for the purpose of response evaluation or clinical trial registration. After WLE/M-NBI and pCLE, each residual GC lesion was biopsied for histological analysis. A total of 23 patients were enrolled between January 2018 and June 2020. Overall, pCLE showed significantly higher sensitivity and negative predictive value than WLE/M-NBI. The accuracy of pCLE was superior to that of WLE/M-NBI. Moreover, pCLE showed better predictive ability for residual GC than WLE/M-NBI, while WLE/M-NBI and pCLE showed inconsistent results. pCLE diagnosed residual GC more accurately than WLE/M-NBI, which resulted in an increased number of GC tissues collected during the endoscopic biopsy.

LC3B, mTOR, AMPK Are Molecular Targets for Neoadjuvant Chemotherapy in Gastric Cancers

Autophagy plays a dual role in oncogenesis processes. On one hand, autophagy enhances the cell resistance to oncogenic factors, and on the other hand, it participates in the tumor progression. The aim of the study was to find the associations between the effectiveness of the FLOT regimen in resectable gastric cancers (GCs) with the key autophagy-related proteins. Materials and Methods: The study included 34 patients with morphologically verified gastric cancer. All patients had FLOT neoadjunvant chemotherapy (NACT) (fluorouracil, leucovorin, oxaliplatin, and docetaxel) followed by gastrectomy. The studied tissue material was the non-transformed and tumor tissues obtained during diagnostic video gastroscopy in patients before the start of the combined treatment and after surgical treatment, frozen after collection. The LC3B, mTOR, and AMPK expression was determined by real-time PCR. The content of the LC3B protein was determined by Western blotting analysis. Results: The mRNA level and the content of the LC3B protein were associated with the tumor stage and the presence of signet ring cells. The AMPK mRNA level was increased in patients with the T4N0-2M0 stage by 37.7 and 7.33 times, which was consequently compared with patients with the T2N0M0 and T3N0-1M0 stages. The opposite changes in the mTOR and AMPK in the GCs before anti-cancer therapy were noted. The tumor size and regional lymph node affections were associated with a decrease in the mTOR mRNA level. A decrease in the mTOR expression was accompanied by an increase in the AMPK expression in the GCs. The mTOR expression was reduced in patients with a cancer spreading; in contrast, AMPK grew with the tumor size. There was an increase in the LC3B expression, which can probably determine the response to therapy. An increase in LC3B mRNA before the start of treatment and the protein content in cancers after NACT with a decrease in therapy effectiveness was recorded. There was an increase in the protein level in patients with partial regression and stabilization by 3.65 and 5.78 times, respectively, when compared with patients with complete tumor regression was noted. Conclusions: The anticancer effectiveness in GCS is down to the LC3B, mTOR, and AMPK expression. These were found to be entire molecular targets affecting the cancer progression and metastasis as well as the NACT effectiveness.

Single-cell RNA-seq dissecting heterogeneity of tumor cells and comprehensive dynamics in tumor microenvironment during lymph nodes metastasis in gastric cancer

Lymph node metastasis is the common metastasis route of gastric cancer. However, until now, heterogeneities of tumor cells and tumor microenvironment in primary tumors (PT) and metastatic lymph nodes (MLN) of gastric cancer (GC) remains uncharacterized. In this study, scRNA-seq was performed on tissues from PT and MLN of gastric cancer. Trajectory analysis and function enrichment analyses were conducted to decode the underlying mechanisms contributing to LN metastasis of gastric cancer. Heterogeneous composition of immune cells and distant intercellular interactions in PT and MLN were analyzed. Based on the generated single cell transcriptome profiles, dynamics of gene expressions in cancer cells between PT and MLN were characterized. Moreover, we reconstructed the developmental trajectory of GC cells' metastasis to LN and identified two sub-types of GC cells with distinct potentials of having malignant biological behaviors. We characterized the repression of neutrophil polarization associated genes, like LCN2, which would contribute to LN metastasis, and histochemistry experiments validated our findings. Additionally, heterogeneity in neutrophils, rather than macrophages, was characterized. Immune checkpoint associated interaction of SPP1 was found active in MLN. In conclusion, we decode the dynamics of tumor cells during LN metastasis in GC and to identify a sub-type of GC cells with potentials of LN metastasis. Our data indicated that the disordering the neutrophils polarization and maturation and the activation of immune checkpoint SPP1 might contribute to LN metastasis in GC, providing a novel insight on the mechanism and potential therapeutic targets of LN metastasis in GC. This article is protected by copyright. All rights reserved.

Potential Therapeutic Action of Autophagy in Gastric Cancer Managements: Novel Treatment Strategies and Pharmacological Interventions

Gastric cancer (GC), second most leading cause of cancer-associated mortality globally, is the cancer of gastrointestinal tract in which malignant cells form in lining of the stomach, resulting in indigestion, pain, and stomach discomfort. Autophagy is an intracellular system in which misfolded, aggregated, and damaged proteins, as well as organelles, are degraded by the lysosomal pathway, and avoiding abnormal accumulation of huge quantities of harmful cellular constituents. However, the exact molecular mechanism of autophagy-mediated GC management has not been clearly elucidated. Here, we emphasized the role of autophagy in the modulation and development of GC transformation in addition to underlying the molecular mechanisms of autophagy-mediated regulation of GC. Accumulating evidences have revealed that targeting autophagy by small molecule activators or inhibitors has become one of the greatest auspicious approaches for GC managements. Particularly, it has been verified that phytochemicals play an important role in treatment as well as prevention of GC. However, use of combination therapies of autophagy modulators in order to overcome the drug resistance through GC treatment will provide novel opportunities to develop promising GC therapeutic approaches. In addition, investigations of the pathophysiological mechanism of GC with potential challenges are urgently needed, as well as limitations of the modulation of autophagy-mediated therapeutic strategies. Therefore, in this review, we would like to deliver an existing standard molecular treatment strategy focusing on the relationship between chemotherapeutic drugs and autophagy, which will help to improve the current treatments of GC patients.

Targeting regulated cell death in tumor nanomedicines

Nanomedicines hold great potential in anticancer therapy by modulating the biodistribution of nanomaterials and initiating targeted oxidative stress damage, but they are also limited by the inherent self-protection mechanism and the evolutionary treatment resistance of cancer cells. New emerging explorations of regulated cell death (RCD), including processes related to autophagy, ferroptosis, pyroptosis, and necroptosis, substantially contribute to the augmented therapeutic efficiency of tumors by increasing the sensitivity of cancer cells to apoptosis. Herein, paradigmatic studies of RCD-mediated synergistic tumor nanotherapeutics are introduced, such as regulating autophagy-enhanced photodynamic therapy (PDT), targeting ferroptosis-sensitized sonodynamic therapy (SDT), inducing necroptosis-augmented photothermal therapy (PTT), and initiating pyroptosis-collaborative chemodynamic therapy (CDT), and the coordination mechanisms are discussed in detail. Multiangle analyses addressing the present challenges and upcoming prospects of RCD-based nanomedicines have also been highlighted and prospected for their further strengthening and the broadening of their application scope. It is believed that up-and-coming coadjutant therapeutic methodologies based on RCDs will considerably impact precision nanomedicine for cancer.

Expression and Content of Protein LC3B in Gastric Cancer Tissue, Relationship with Expression of mTOR, AMPK in Gastric Cancer Tissue and HER2 and PD-L1 Status of the Tumor

Analysis of HER2 status of the tumor and expression of mTOR, AMPK showed a decrease in mTOR mRNA level in HER2⁺ tumors in comparison with HER- status. The appearance of PD-L1⁺ transformed cells in the tumor was associated with increased expression of the LC3B gene and elevated content of the corresponding protein measured after treatment.

WITHDRAWN: FOXC1 modulates stem-like cell properties and chemoresistance through hedgehog and EMT signaling in gastric adenocarcinoma

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Rutin attenuates Sorafenib-induced Chemoresistance and Autophagy in Hepatocellular Carcinoma by regulating BANCR/miRNA-590-5P/OLR1 Axis

Rutin, the main component of Potentilla discolor Bunge, was proven to exhibit anti-tumor properties. Sorafenib (SO) is conventionally used in chemotherapy against hepatocellular carcinoma (HCC), but acquired resistance developed during long-term therapy limits its benefits. This study aimed to explore the molecular mechanism of rutin in SO-induced autophagy and chemoresistance in HCC. Sixty-eight paired HCC patients who received the same chemotherapy treatment were obtained. We also established two SO resistance cell lines and then utilized high-throughput RNA sequencing to explore their long non-coding RNA (lncRNA) expression profiles. The target microRNA (miRNA) and downstream mRNA were also explored. Our results indicated that rutin treatment attenuates autophagy and BANCR expression in SO resistance cells. Transmission electron microscopy clearly showed a significantly decreased number of autophagosomes after rutin-treated HepG2/SO and HCCLM3/SO cells. BANCR knockdown promotes the sensitivity of SO resistance cells to SO. Further study found that BANCR acts as a molecular sponge of miR-590-5P to sequester miR-590-5P away from oxidized low-density lipoprotein receptor 1 (OLR1) in HCC cells. Furthermore, in vivo study demonstrated that rutin could inhibit autophagy through the BANCR/miRNA-590-5P/OLR1 axis. Our findings suggest that rutin could regulate autophagy by regulating BANCR/miRNA-590-5P/OLR1 axis.

Pseudo-ginsenoside Rh2 Induces Protective Autophagy in Hepatocellular Carcinoma HepG2 Cells

BACKGROUND

Pseudo-ginsenoside-Rh2 (pseudo-G-Rh2), a novel derivative of ginsenoside Rh2, is reported to exert a pro-apoptotic effect on various malignancies. However, whether this anti-cancer action of pseudo-G-Rh2 involves autophagy remains to be determined and explored.

OBJECTIVES

Investigation of pseudo-G-Rh2-induced apoptosis and autophagy and the underlying mechanism.

METHODS

In the present study, the MTT assay was used for evaluating cell viability and the lactate dehydrogenase (LDH) assay was performed to assess cell toxicity. Autophagy evaluation was performed using monodansylcadaverine (MDC) staining and transmission electron microscopy (TEM). The levels of autophagy-associated and apoptosis-associated proteins were determined using Western blotting. The Annexin V FITC/propidium iodide (PI) assay was used to assess apoptosis.

RESULTS

The Annexin V FITC/PI assay revealed that the percentage of apoptotic cells in HepG2 cells at concentrations 0, 20, 40, and 60 μM was 3.75%±1.37%, 5.70%±1.04%, 12.30%±2.10%, and 34.26%±4.73%, respectively. Pseudo-G-Rh2 was observed to significantly increase the expressions of BAX, cleaved-caspase-3, and cleaved-caspase-9, while it decreased the Bcl-2 expression. MDC and TEM analyses revealed that pseudo-G-Rh2 at concentrations 20, 40, and 60 μM significantly facilitated the accumulation of autophagosomes and autolysosomes within the HepG2 cells. Moreover, pseudo-G-Rh2 significantly increased the expressions of LC3 Ⅱ/LC3 Ⅰ, and Beclin-1 and decreased the expression of p62. The Annexin V FITC/PI assay also revealed that in comparison to the pseudo-G-Rh2 group, the concurrent treatment with pseudo-G-Rh2 and an autophagy inhibitor (CQ or 3-MA) significantly induced distinct apoptosis. In addition, pseudo-G-Rh2 activated AMPK and inhibited the PI3K/Akt/mTOR pathway in a concentration-dependent manner. Pseudo-G-Rh2 is similar to the current patents, which enhanced its anti-cancer activity by combining with autophagy inhibitors.

CONCLUSION

Pseudo-G-Rh2 could induce protective autophagy in HepG2 cells, at least in part, via AMPK and the PI3K/Akt/mTOR pathway.

Molecular and cellular basis of the anticancer activity of the prenylated flavonoid icaritin in hepatocellular carcinoma

The prenylated flavonoid icaritin (ICT) is currently undergoing phase 3 clinical trial for the treatment of advanced hepatocellular carcinoma (HCC), based on a solid array of preclinical and clinical data. The antitumor activity originates from the capacity of the drug to modulate several signaling effectors in cancer cells, mainly the estrogen receptor splice variant ERα36, the transcription factors STAT3 and NFκB, and the chemokine receptor CXCR4. Recent studies have implicated additional components, including different microRNAs, the generation of reactive oxygen species and the targeting of sphingosine kinase-1. ICT also engages the RAGE-HMGB1 signaling route and modulates the apoptosis/autophagy crosstalk to promote its anticancer activity. In addition, ICT exerts profound changes on the tumor microenvironment to favor an immune-response. Collectively, these multiple biochemical and cellular characteristics confer to ICT a robust activity profile which can be exploited to treat HCC, as well as other cancers, including glioblastoma and onco-hematological diseases such as chronic myeloid leukemia. This review provides an update of the pharmacological properties of ICT and its metabolic characteristics. It also addresses the design of derivatives, including both natural products and synthetic molecules, such as SNG1153 also in clinical trial. The prenylated flavonoid ICT deserves attention as a multifunctional natural product potentially useful to improve the treatment of advanced hepatocellular carcinoma.