Resveratrol induces cell cycle arrest in human gastric cancer MGC803 cells via the PTEN-regulated PI3K/Akt signaling pathway

Modulation of the PI3K/Akt signaling pathway by resveratrol in cancer: molecular mechanisms and therapeutic opportunity

The phosphatidylinositol 3-kinase (PI3K)/Akt pathway is a critical intracellular signaling pathway that is pivotal in various cellular functions. It is in senescence, survival, and growth under normal physiological and pathological conditions, including neoplasms. Additionally, this pathway has been recognized as essential for the regulation of the cell cycle. Several previous studies have indicated that the PI3K/Akt signaling pathway can be influenced by various natural products, with resveratrol (3,4',5-trihydroxy-trans-stilbene) being a particularly important phytoalexin polyphenol in this context. This review explores the impact of the PI3K/Akt signaling pathway on the initiation and advancement of various cancerous conditions and the potential of resveratrol to target this signaling mechanism. The review begins by summarizing the anti-tumor capabilities of resveratrol and then emphasizes the significant role of the PI3K/Akt signaling pathway in the progression of multiple malignancies. Finally, we discuss the therapeutic effects of resveratrol on human neoplasms, from brain cancers to gastrointestinal malignancies, through regulation of this signaling cascade.

Natural Products and Altered Metabolism in Cancer: Therapeutic Targets and Mechanisms of Action

Cancer is characterized by uncontrolled cell proliferation and the dysregulation of numerous biological functions, including metabolism. Because of the potential implications of targeted therapies, the metabolic alterations seen in cancer cells, such as the Warburg effect and disruptions in lipid and amino acid metabolism, have gained attention in cancer research. In this review, we delve into recent research examining the influence of natural products on altered cancer metabolism. Natural products were selected based on their ability to target cancer's altered metabolism. We identified the targets and explored the mechanisms of action of these natural products in influencing cellular energetics. Studies discussed in this review provide a solid ground for researchers to consider natural products in cancer treatment alone and in combination with conventional anticancer therapies.

Anticancer properties and metabolomic profiling of Shorea roxburghii extracts toward gastrointestinal cancer cell lines

BACKGROUND

Gastrointestinal cancer (GIC) ranks as the highest cause of cancer-related deaths globally. GIC patients are often diagnosed at advanced stages, limiting effective treatment options. Chemotherapy, the common GIC recommendation, has significant disadvantages such as toxicity and adverse effects. Natural products contain substances with diverse pharmacological characteristics that promise for use in cancer therapeutics. In this study, the flower of renowned Asian medicinal plant, Shorea roxburghii was collected and extracted to investigate its phytochemical contents, antioxidant, and anticancer properties on GIC cells.

METHODS

The phytochemical contents of Shorea roxburghii extract were assessed using suitable methods. Phenolic content was determined through the Folin-Ciocalteu method, while flavonoids were quantified using the aluminum chloride (AlCl3) method. Antioxidant activity was evaluated using the FRAP and DPPH assays. Cytotoxicity was assessed in GIC cell lines via the MTT assay. Additionally, intracellular ROS levels and apoptosis were examined through flow cytometry techniques. The correlation between GIC cell viability and phytochemicals, 1H-NMR analysis was conducted.

RESULTS

Among the four different solvent extracts, ethyl acetate extract had the highest phenolic and flavonoid contents. Water extract exhibited the strongest reducing power and DPPH scavenging activity following by ethyl acetate. Interestingly, ethyl acetate extract demonstrated the highest inhibitory activity against three GIC cell lines (KKU-213B, HepG2, AGS) with IC50 values of 91.60 µg/ml, 39.38 µg/ml, and 35.59 µg/ml, while showing less toxicity to normal fibroblast cells. Ethyl acetate extract induced reactive oxygen species and apoptosis in GIC cell lines by downregulating anti-apoptotic protein Bcl-2. Metabolic profiling-based screening revealed a positive association between reduced GIC cell viability and phytochemicals like cinnamic acid and its derivatives, ferulic acid and coumaric acid.

CONCLUSIONS

This study highlights the potential of natural compounds in Shorea roxburghii in the development of more effective and safer anticancer agents as options for GIC as well as shedding light on new avenues for cancer treatment.

Advances for pharmacological activities of Polygonum cuspidatum - A review

CONTEXT

Polygonum cuspidatum Sieb. et Zucc (Polygonaceae), the root of which is included in the Chinese Pharmcopoeia under the name 'Huzhang', has a long history as a medicinal plant and vegetable. Polygonum cuspidatum has been used in traditional Chinese medicine for the treatment of inflammation, hyperlipemia, etc.

OBJECTIVE

This article reviews the pharmacological action and the clinical applications of Polygonum cuspidatum and its extracts, whether in vivo or in vitro. We also summarized the main phytochemical constituents and pharmacokinetics of Polygonum cuspidatum and its extracts.

METHODS

The data were retrieved from major medical databases, such as CNKI, PubMed, and SinoMed, from 2014 to 2022. Polygonum cuspidatum, pharmacology, toxicity, clinical application, and pharmacokinetics were used as keywords.

RESULTS

The rhizomes, leaves, and flowers of Polygonum cuspidatum have different phytochemical constituents. The plant contains flavonoids, anthraquinones, and stilbenes. Polygonum cuspidatum and the extracts have anti-inflammatory, antioxidation, anticancer, heart protection, and other pharmacological effects. It is used in the clinics to treat dizziness, headaches, traumatic injuries, and water and fire burns.

CONCLUSIONS

Polygonum cuspidatum has the potential to treat many diseases, such as arthritis, ulcerative colitis, asthma, and cardiac hypertrophy. It has a broad range of medicinal applications, but mainly focused on root medication; its aerial parts should receive more attention. Pharmacokinetics also need to be further investigated.

The signaling pathways and targets of natural products from traditional Chinese medicine treating gastric cancer provide new candidate therapeutic strategies

Gastric cancer (GC) is one of the severe malignancies with high incidence and mortality, especially in Eastern Asian countries. Significant advancements have been made in diagnosing and treating GC over the past few decades, resulting in tremendous improvements in patient survival. In recent years, traditional Chinese medicine (TCM) has garnered considerable attention as an alternative therapeutic approach for GC due to its multicomponent and multitarget characteristics. Consequently, natural products found in TCM have attracted researchers' attention, as growing evidence suggests that these natural products can impede GC progression by regulating various biological processes. Nevertheless, their molecular mechanisms are not systematically uncovered. Here, we review the major signaling pathways involved in GC development. Additionally, clinical GC samples were analyzed. Moreover, the anti-GC effects of natural products, their underlying mechanisms and potential targets were summarized. These summaries are intended to facilitate further relevant research, and accelerate the clinical applications of natural products in GC treatment.

Metformin enhances anti-cancer properties of resveratrol in MCF-7 breast cancer cells via induction of apoptosis, autophagy and alteration in cell cycle distribution

Breast cancer is the fifth leading cause of death, worldwide affecting both genders. Accumulating evidence suggests that metformin, an oral hypoglycemic agent used in the management of type 2 diabetes, exerts anti-tumor effects in many cancers, including the breast cancer. Resveratrol, a natural product found abundantly in many fruits, exhibits marked cytotoxic and pro-oxidant effects. This study was designed to investigate the effect of metformin in combination with resveratrol and cisplatin in MCF-7 cells. Study groups were as follows: untreated control group, single treatment groups (metformin, resveratrol, and cisplatin), double treatment groups (metformin + resveratrol, metformin + cisplatin, and cisplatin + resveratrol) and triple treatment groups (metformin + resveratrol + cisplatin). Our results indicated that metformin inhibits proliferation of MCF-7 cells, an effect that was associated with ROS production and G0/G1 cell cycle arrest, but not apoptosis. Moreover, resveratrol suppressed the proliferation of MCF-7 cells by induction of apoptosis as well as cell cycle arrest. Notably, a significant inhibitory effect in the co-treatment of metformin, resveratrol, and cisplatin was observed which was attributed to induction of autophagy-mediated cell death and apoptosis along cell cycle arrest. In conclusion, our results advocate the anti-cancer properties of metformin and resveratrol on MCF-7 cell s via induction of cell cycle arrest. Additionally, synergistic anti-cancer effects of metformin in a triple combination with cisplatin and resveratrol was attributed to induction of autophagy-mediated cell death and apoptosis along cell cycle arrest. Based on our findings it is proposed that patients may benefit from addition of a drug with a safe profile to conventional anticancer therapies.

A renewed concept on the MAPK signaling pathway in cancers: Polyphenols as a choice of therapeutics

Abnormalities in the mitogen-activated protein kinase (MAPK) signaling pathway are a key contributor to the carcinogenesis process and have therefore been implicated in several aspects of tumorigenesis, including cell differentiation, proliferation, invasion, angiogenesis, apoptosis, and metastasis. This pathway offers multiple molecular targets that may be modulated for anticancer activity and is of great interest for several malignancies. Polyphenols from various dietary sources have been observed to interfere with certain aspects of this pathway and consequently play a substantial role in the development and progression of cancer by suppressing cell growth, inactivating carcinogens, blocking angiogenesis, causing cell death, and changing immunity. A good number of polyphenolic compounds have shown promising outcomes in numerous pieces of research and are currently being investigated clinically to treat cancer patients. The current study concentrates on the role of the MAPK pathway in the development and metastasis of cancer, with particular emphasis on dietary polyphenolic compounds that influence the different MAPK sub-pathways to obtain an anticancer effect. This study aims to convey an overview of the various aspects of the MAPK pathway in cancer development and invasion, as well as a review of the advances achieved in the development of polyphenols to modulate the MAPK signaling pathway for better treatment of cancer.

Disease-associated regulation of gene expression by resveratrol: Special focus on the PI3K/AKT signaling pathway

Resveratrol (3,5,4′-trihydroxy-trans-stilbene) is a natural phenol that is present in the skin of the grape, blueberry, raspberry, mulberry, and peanut. This substance is synthesized in these plants following injury or exposure to pathogens. Resveratrol is used as a dietary supplement for a long time and its effects have been assessed in animal models of human disorders. It has potential beneficial effects in diverse pathological conditions such as diabetes mellitus, obesity, hypertension, neoplastic conditions, Alzheimer's disease, and cardiovascular disorders. Notably, resveratrol has been found to affect the expression of several genes including cytokine coding genes, caspases, matrix metalloproteinases, adhesion molecules, and growth factors. Moreover, it can modulate the activity of several signaling pathways such as PI3K/AKT, Wnt, NF-κB, and Notch pathways. In the current review, we summarize the results of studies that reported modulatory effects of resveratrol on the expression of genes and the activity of signaling pathways. We explain these results in two distinct sections of non-neoplastic and neoplastic conditions.

Flavonoids Targeting the mTOR Signaling Cascades in Cancer: A Potential Crosstalk in Anti-Breast Cancer Therapy

Cancer is one of the leading causes of death worldwide. Breast cancer is the second leading cause of death in women, with triple-negative breast cancer being the most lethal and aggressive form. Conventional therapies, such as radiation, surgery, hormonal, immune, gene, and chemotherapy, are widely used, but their therapeutic efficacy is limited due to adverse side effects, toxicities, resistance, recurrence, and therapeutic failure. Many molecules have been identified and investigated as potential therapeutic agents for breast cancer, with a focus on various signaling pathways. Flavonoids are a versatile class of phytochemicals that have been used in cancer treatment to overcome issues with traditional therapies. Cell proliferation, growth, apoptosis, autophagy, and survival are all controlled by mammalian target of rapamycin (mTOR) signaling. Flavonoids target mTOR signaling in breast cancer, and when this signaling pathway is regulated or deregulated, various signaling pathways provide potential therapeutic means. The role of various flavonoids as phytochemicals in targeting mTOR signaling pathways in breast cancer is highlighted in this review.

Applications of resveratrol in the treatment of gastrointestinal cancer

Natural product compounds have lately attracted interest in the scientific community as a possible treatment for gastrointestinal (GI) cancer, due to their anti-inflammatory and anticancer properties. There are many preclinical, clinical, and epidemiological studies, suggesting that the consumption of polyphenol compounds, which are abundant in vegetables, grains, fruits, and pulses, may help to prevent various illnesses and disorders from developing, including several GI cancers. The development of GI malignancies follows a well-known path, in which normal gastrointestinal cells acquire abnormalities in their genetic composition, causing the cells to continuously proliferate, and metastasize to other sites, especially the brain and liver. Natural compounds with the ability to affect oncogenic pathways might be possible treatments for GI malignancies, and could easily be tested in clinical trials. Resveratrol is a non-flavonoid polyphenol and a natural stilbene, acting as a phytoestrogen with anti-cancer, cardioprotective, anti-oxidant, and anti-inflammatory properties. Resveratrol has been shown to overcome resistance mechanisms in cancer cells, and when combined with conventional anticancer drugs, could sensitize cancer cells to chemotherapy. Several new resveratrol analogs and nanostructured delivery vehicles with improved anti-GI cancer efficacy, absorption, and pharmacokinetic profiles have already been developed. This present review focuses on the in vitro and in vivo effects of resveratrol on GI cancers, as well as the underlying molecular mechanisms of action.

Resveratrol enhances A1 and hinders A2A adenosine receptors signaling in both HeLa and SH-SY5Y cells: Potential mechanism of its antitumoral action

Despite great efforts, effective treatment against cancer has not yet been found. However, natural compounds such as the polyphenol resveratrol have emerged as promising preventive agent in cancer therapy. The mode of action of resveratrol is still poorly understood, but it can modulate many signaling pathways related to the initiation and progression of cancer. Adenosinergic signaling may be involved in the antitumoral action of resveratrol since resveratrol binds to the orthosteric binding site of adenosine A_2A receptors and acts as a non-selective agonist for adenosine receptors. In the present study, we measured the impact of resveratrol treatment on different adenosinergic pathway components (i.e. adenosine receptors levels, 5'-nucleotidase, adenosine deaminase, and adenylyl cyclase activities, protein kinase A levels, intracellular adenosine and other related metabolites levels) and cell viability and proliferation in HeLa and SH-SY5Y cell lines. Results revealed changes leading to turning off cAMP signaling such as decreased levels of A_2A receptors and reduced adenylyl cyclase activation, increased levels of A₁ receptors and increased adenylyl cyclase inhibition, and lower levels of PKA. All these changes could contribute to the antitumoral action of resveratrol. Interestingly, these effects were almost identical in HeLa and SH-SY5Y cells suggesting that resveratrol enhances A₁ and hinders A_2A adenosine receptors signaling as part of a potential mechanism of antitumoral action.

Cytotoxic and Proapoptotic Effects of Resveratrol in In Vitro Studies on Selected Types of Gastrointestinal Cancers

Cancer diseases are currently one of the greatest health challenges in clinical medicine worldwide. Classic methods of treatment often lead to numerous side effects, including the development of multidrug resistance. For this reason, increasing hope is being placed on compounds of natural origin, mainly due to their pleiotropic effect on different types of cells, protective effect on normal cells and toxic effect on cancerous ones. The most studied group are the polyphenolic compounds, which include resveratrol. The effectiveness of polyphenols in the treatment and prevention of many diseases, including cancer of various origins, has become the basis of many scientific studies. The anticancer effect of resveratrol has been demonstrated at all stages of the carcinogenesis process. Additionally, whether administered by itself or in combination with cytostatics, it may play a significant role in the process of reversing multidrug resistance. A review of the effects of resveratrol in in vitro conditions proves that it has a stronger or weaker antiproliferative and proapoptotic effect on the cells of certain neoplasms of the gastrointestinal tract. Despite the differences in the effect of this compound on different types of cancer, a similar tendency can be observed especially regarding the correlation between the concentration of the compound and the incubation time on the one hand and the antitumour effect on the other hand. The information included in this review may prove helpful in planning in vivo and clinical studies in the future.

Gastroprotective Effects of Polyphenols against Various Gastro-Intestinal Disorders: A Mini-Review with Special Focus on Clinical Evidence

Polyphenols are classified as an organic chemical with phenolic units that display an array of biological functions. However, polyphenols have very low bioavailability and stability, which make polyphenols a less bioactive compound. Many researchers have indicated that several factors might affect the efficiency and the metabolism (biotransformation) of various polyphenols, which include the gut microbiota, structure, and physical properties as well as its interactions with other dietary nutrients (macromolecules). Hence, this mini-review covers the two-way interaction between polyphenols and gut microbiota (interplay) and how polyphenols are metabolized (biotransformation) to produce various polyphenolic metabolites. Moreover, the protective effects of numerous polyphenols and their metabolites against various gastrointestinal disorders/diseases including gastritis, gastric cancer, colorectal cancer, inflammatory bowel disease (IBD) like ulcerative colitis (UC), Crohn’s disease (CD), and irritable bowel syndrome (IBS) like celiac disease (CED) are discussed. For this review, the authors chose only a few popular polyphenols (green tea polyphenol, curcumin, resveratrol, quercetin), and a discussion of their proposed mechanism underpinning the gastroprotection was elaborated with a special focus on clinical evidence. Overall, this contribution would help the general population and science community to identify a potent polyphenol with strong antioxidant, anti-inflammatory, anti-cancer, prebiotic, and immunomodulatory properties to combat various gut-related diseases or disorders (complementary therapy) along with modified lifestyle pattern and standard gastroprotective drugs. However, the data from clinical trials are much limited and hence many large-scale clinical trials should be performed (with different form/metabolites and dose) to confirm the gastroprotective activity of the above-mentioned polyphenols and their metabolites before recommendation.

Dietary polyphenols suppress chronic inflammation by modulation of multiple inflammation-associated cell signaling pathways

The high failure rate of the reductionist approach to discover effective and safe drugs to treat chronic inflammatory diseases has led scientists to seek alternative ways. Recently, targeting cell signaling pathways has been utilized as an innovative approach to discover drug leads from natural products. Cell signaling mechanisms have been identified playing key role in diverse diseases by inducing proliferation, cell survival and apoptosis. Phytochemicals are known to be able to modulate the cellular and molecular networks which are associated to chronic diseases including cancer-associated inflammation. In this review, the roles of dietary polyphenols (apigenin, kaempferol, quercetin, curcumin, genistein, isoliquiritigenin, resveratrol and gallic acid) in modulating multiple inflammation-associated cell signaling networks are deliberated. Scientific databases on suppressive effects of the polyphenols on chronic inflammation via modulation of the pathways especially in the recent five years are gathered and critically analyzed. The polyphenols are able to modulate several inflammation-associated cell signaling pathways, namely nuclear factor-kappa β, mitogen activated protein kinases, Wnt/β-catenin and phosphatidylinositol 3-kinase and protein kinase B via selective actions on various components of the networks. The suppressive effects of the polyphenols on the multiple cell signaling pathways reveal their potential use in prevention and treatment of chronic inflammatory disorders. Understanding the mechanistic effects involved in modulation of the signaling pathways by the polyphenols is necessary for lead identification and development of future functional foods for prevention and treatment of chronic inflammatory diseases.

Anti-tumor activity of resveratrol against gastric cancer: a review of recent advances with an emphasis on molecular pathways

Gastric cancer (GC) is one of the most common cancers with high malignancy. In spite of the great development in diagnostic tools and application of anti-tumor drugs, we have not witnessed a significant increase in the survival time of patients with GC. Multiple studies have revealed that Wnt, Nrf2, MAPK, and PI3K/Akt signaling pathways are involved in GC invasion. Besides, long non-coding RNAs and microRNAs function as upstream mediators in GC malignancy. GC cells have acquired resistance to currently applied anti-tumor drugs. Besides, combination therapy is associated with higher anti-tumor activity. Resveratrol (Res) is a non-flavonoid polyphenol with high anti-tumor activity used in treatment of various cancers. A number of studies have demonstrated the potential of Res in regulation of molecular pathways involved in cancer malignancy. At the present review, we show that Res targets a variety of signaling pathways to induce apoptotic cell death and simultaneously, to inhibit the migration and metastasis of GC cells.

Resveratrol, curcumin, paclitaxel and miRNAs mediated regulation of PI3K/Akt/mTOR pathway: go four better to treat bladder cancer

Bladder cancer (BC) is a leading cause of death among urothelial malignancies that more commonly affect male population. Poor prognosis and resistance to chemotherapy are the two most important characteristics of this disease. PI3K/Akt/mTOR signaling pathway has been considered pivotal in the regulation of proliferation, migration, invasiveness, and metastasis. Deregulation of PI3K/Akt/mTOR signaling has been found in 40% of bladder cancers. Several microRNAs (miRNAs) have been reported to interact with the PI3K/Akt/mTOR signaling pathway with a different possible role in proliferation and apoptosis in bladder cancer. Thus, miRNAs can be used as potential biomarkers for BC. Natural compounds have been in the spotlight for the past decade due to their effective anti-proliferative capabilities. However, little is known of its possible effects in bladder cancer. The aim of this review is to discuss the interplay between PI3K/Akt/mTOR, miRNAs, and natural compounds and emphasize the importance of miRNAs as biomarkers and resveratrol, curcumin and paclitaxel as a possible therapeutic approach against bladder cancer.

PTEN, a Barrier for Proliferation and Metastasis of Gastric Cancer Cells: From Molecular Pathways to Targeting and Regulation

Cancer is one of the life-threatening disorders that, in spite of excellent advances in medicine and technology, there is no effective cure for. Surgery, chemotherapy, and radiotherapy are extensively applied in cancer therapy, but their efficacy in eradication of cancer cells, suppressing metastasis, and improving overall survival of patients is low. This is due to uncontrolled proliferation of cancer cells and their high migratory ability. Finding molecular pathways involved in malignant behavior of cancer cells can pave the road to effective cancer therapy. In the present review, we focus on phosphatase and tensin homolog (PTEN) signaling as a tumor-suppressor molecular pathway in gastric cancer (GC). PTEN inhibits the PI3K/Akt pathway from interfering with the migration and growth of GC cells. Its activation leads to better survival of patients with GC. Different upstream mediators of PTEN in GC have been identified that can regulate PTEN in suppressing growth and invasion of GC cells, such as microRNAs, long non-coding RNAs, and circular RNAs. It seems that antitumor agents enhance the expression of PTEN in overcoming GC. This review focuses on aforementioned topics to provide a new insight into involvement of PTEN and its downstream and upstream mediators in GC. This will direct further studies for evaluation of novel signaling networks and their targeting for suppressing GC progression.

Gastric-cancer-derived mesenchymal stem cells: a promising target for resveratrol in the suppression of gastric cancer metastasis

The tumor microenvironment (TM) is an essential factor of tumor progression. Mesenchymal stem cells (MSCs) are important components of the TM and play critical roles in cancer metastasis. Resveratrol (RES) is a potential antitumor drug that has attracted extensive attention. However, it remains unclear whether RES can exert its antitumor activity by targeting MSCs located in the TM. In this study, we demonstrated that the conditioned medium of gastric-cancer-derived MSCs (GC-MSCs) promoted gastric cancer (GC) metastasis and facilitated the progression of epithelialmesenchymal transition (EMT) of GC cells. However, after pretreatment with RES, the prometastatic effect of GC-MSCs on GC cells was reversed. Furthermore, RES reduced GC-MSC (IL-6, IL-8, MCP-1, VEGF) gene expression and protein secretion, and counteracted the activation of the GC-MSC-induced Wnt/β-catenin signaling of GC cells, with less β-catenin nuclear transport and declined expression of β-catenin, CD44, and CyclinD3 in GC cells. Re-expression of β-catenin impaired the inhibitory effect of RES on GC cells. In conclusion, RES restricted the mobility increase of GC cells and reversed the progress of EMT induced by GC-MSCs by inactivating the Wnt/β-catenin signaling. GC-MSCs are promising target for RES in the inhibition of GC metastasis.

Mechanisms of resveratrol in the prevention and treatment of gastrointestinal cancer

Gastrointestinal (GI) cancer is one of the leading causes of cancer-related deaths worldwide. According to the Global Cancer Statistics, colorectal cancer is the second leading cause of cancer-related mortality, closely followed by gastric cancer (GC). Environmental, dietary, and lifestyle factors including cigarette smoking, alcohol intake, and genetics are the most important risk factors for GI cancer. Furthermore, infections caused by Helicobacter pylori are a major cause of GC initiation. Despite improvements in conventional therapies, including surgery, chemotherapy, and radiotherapy, the length or quality of life of patients with advanced GI cancer is still poor because of delayed diagnosis, recurrence and side effect. Resveratrol (3, 4, 5-trihydroxy-trans-stilbene; Res), a natural polyphenolic compound, reportedly has various pharmacologic functions including anti-oxidant, anti-inflammatory, anti-cancer, and cardioprotective functions. Many studies have demonstrated that Res also exerts a chemopreventive effect on GI cancer. Research investigating the anti-cancer mechanism of Res for the prevention and treatment of GI cancer has implicated multiple pathways including oxidative stress, cell proliferation, and apoptosis. Therefore, this paper provides a review of the function and molecular mechanisms of Res in the prevention and treatment of GI cancer.

Experimental Study on the Effect of a Weifufang on Human Gastric Adenocarcinoma Cell Line BGC-823 Xenografts and PTEN Gene Expression in Nude Mice

Background: This study aims at investigating the effect of the Weifufang, an effective prescription for the treatment of gastric cancer developed by the Traditional Chinese Medicine (TCM)/Combination of TCM and Western Medicine Department of the Hunan Cancer Hospital, on gastric cancer xenografts in nude mice and its effect on the PTEN gene; it also aims at exploring the possible tumor suppression mechanism. Methods: Nude mice with xenografts were treated with different concentrations of the Weifufang for 2 weeks, and changes in tumor volume were observed. The histopathology of the tumor was detected by hematoxylin and eosin staining; PTEN gene expression in tumor tissues was detected by immunohistochemistry (IHC) and western blot. Results: After 2 weeks of treatment, tumor inhibition rates in the 5-flourouracil (5-FU) group, and in the Weifufang low-, middle-, and high-dose groups were 30.67%, 19%, 49.52%, and 29.36%, respectively. The IOD of the PTEN gene was detected by IHC. The values in the water group, the 5-FU group, and the Weifufang low-, middle-, and high-dose groups were 0.013 ± 0.004, 0.085 ± 0.062, 0.041 ± 0.024, 0.128 ± 0.032, and 0.061 ± 0.052, respectively. Except for the 5-FU group, the differences between the gastric compound middle dose-group and the other groups were statistically significant (p < 0.05). Results of PTEN expression detection by western blot: The expression levels in the water group, 5-FU group, and the Weifufang low-, middle-, and high-dose groups were 0.2240 ± 0.0172, 0.4200 ± 0.0228, 0.2760 ± 0.0163, 0.3840 ± 0.0133, and 0.3040 ± 0.0211, respectively. Except for the 5-FU group, differences between the Weifufang middle-dose group and the other groups were statistically significant (p < 0.05). Conclusion: The Weifufang may inhibit the growth of gastric cancer xenografts by upregulating PTEN gene expression. The middle-dose group had the best effect.

Hyperhomocysteinemia inhibits tibial fracture healing in rats through PI3K/AKT signaling pathway

To explore the influence of hyperhomocysteinemia (hHcys) on the tibial fracture healing in rats and its effect on the phosphatidylinositol 3-hydroxy kinase (PI3K)/protein kinase B (AKT) signaling pathway. A total of 36 Sprague-Dawley rats were randomly divided into sham group (n=12), tibial fracture group (n=12) and hHcys + fracture group (n=12). The rats in tibial fracture group underwent the tibial fracture surgery, while the model of tibial fracture and hHcys was established in hHcys + fracture group. The level of plasma homocysteine (Hcy) in each group was analyzed using the full-automatic biochemical analyzer, the fracture stress biomechanical measurement was performed, and the ultimate bending strength and torque were calculated. Moreover, the protein expressions of PI3K and phosphorylated (p)-AKT in tibial tissues were detected using western blotting, the messenger ribonucleic acid (mRNA) levels of Bcl-2 associated X protein (Bax) and caspase-3 were detected using quantitative polymerase chain reaction (qPCR), the apoptosis was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, and the expressions of inflammatory factors were detected via immunohistochemistry. Compared with sham group, tibial fracture group and hHcys + fracture group had a significantly increased level of plasma Hcy, significantly decreased ultimate bending strength and torque, obviously decreased relative protein expressions of PI3K and p-AKT, increased mRNA levels of Bax and caspase-3 and an increased expression of pro-inflammatory factor tumor necrosis factor-α (TNF-α). Compared with tibial fracture group, hHcys + fracture group had a higher level of plasma Hcy, lower ultimate bending strength and torque, lower relative protein expressions of PI3K and p-AKT, higher mRNA levels of Bax and caspase-3, a higher apoptosis rate and a higher expression of TNF-α. hHcys blocks the downstream apoptotic signal transduction, promotes apoptosis and inflammatory response, and affects fracture healing through affecting the PI3K/AKT signaling pathway.

Babao Dan induces gastric cancer cell apoptosis via regulating MAPK and NF-κB signaling pathways

OBJECTIVE

The objective was to further investigate apoptosis induction by Babao Dan (BBD), which supports its anti-tumor mechanisms, using two human gastric cancer cell lines (AGS and MGC80-3).

METHODS

After treatment with various BBD concentrations, cell viability and cytotoxic effects were investigated using methyl thiazolyl tetrazolium (MTT) and lactate dehydrogenase (LDH) assays, respectively. The following indicators of cell apoptosis were evaluated: Annexin V-APC staining, caspase-3/-8/-9 activation, and mitochondrial membrane potential loss. Apoptosis-related protein levels (including Bcl-2-associated X protein [Bax], B-cell CLL/lymphoma 2 [Bcl-2], factor associated suicide [Fas], and Fas ligand [FasL]) were determined by western blot. The following multi-pathway factors were also assessed: p-ERK1/2, p-JNK, p-p38, and p-NF-κB.

RESULTS

The MTT and LDH assays both demonstrated increased BBD cytotoxicity. BBD induced cell apoptosis by stimulating caspase-3/-8/-9 activity and destroying the mitochondrial membrane potential. BBD also regulated key factor expression levels including Bcl-2, Bax, Fas, and FasL and down-regulated protein phosphorylation via the MAPK and NF-κB pathway.

CONCLUSIONS

The possible anti-tumor mechanism is that BBD induces apoptosis via the MAPK and NF-κB signaling pathways.

Modulation of cancer signalling pathway(s) in two -stage mouse skin tumorigenesis by annonacin

Background

Annonacin, an annonaceous acetogenin isolated from Annona muricata has been reported to be strongly cytotoxic against various cell lines, in vitro. Nevertheless, its effect against in vivo tumor promoting activity has not been reported yet. Therefore, this study was aimed to investigate antitumor-promoting activity of annonacin via in vivo two-stage mouse skin tumorigenesis model and its molecular pathways involved.

Methods

Mice were initiated with single dose of 7,12-dimethylbenz[α]anthracene (DMBA) (390 nmol/100 μL) followed by, in subsequent week, repeated promotion (twice weekly; 22 weeks) with 12-O-tetradecanoylphorbol-13-acetate (TPA) (1.7 nmol/100 μL). Annonacin (85 nM) and curcumin (10 mg/kg; reference) were, respectively, applied topically to DMBA/TPA-induced mice 30 min before each TPA application for 22 weeks. Upon termination, histopathological examination of skin, liver and kidney as well as genes and proteins expression analysis were conducted to elucidate the potential mechanism of annonacin.

Results

With comparison to the carcinogen control, Annonacin significantly increased the tumor latency period and reduced the tumor incidence, tumor burden and tumor volume, respectively. In addition, it also suppressed tumorigenesis manifested by significant reduction of hyperkeratosis, dermal papillae and number of keratin pearls on skin tissues. Annonacin also appeared to be non-toxic to liver and kidney. Significant modulation of both AKT, ERK, mTOR, p38, PTEN and Src genes and proteins were also observed in annonacin-targeted signaling pathway(s) against tumorigenesis.

Conclusions

Collectively, results of this study indicate that annonacin is a potential therapeutic compound targeting tumor promoting stage in skin tumorigenesis by modulating multiple gene and protein in cancer signaling pathways without apparent toxicity.

Electronic supplementary material

The online version of this article (10.1186/s12906-019-2650-1) contains supplementary material, which is available to authorized users.

Resveratrol inhibits STAT5 activation through the induction of SHP-1 and SHP-2 tyrosine phosphatases in chronic myelogenous leukemia cells

STAT5 is an important transcription factor that is constitutively activated in various types of malignancies, including chronic myelogenous leukemia (CML). Whether the antitumor effects of resveratrol (RES) are linked to its capability to inhibit STAT5 activation in CML cells was investigated. We found that RES inhibited STAT5 activation in K562 and KU812 cell lines; RES also reduced the STAT5 concentration in the nucleus of K562 and KU812 cells. Protein tyrosine phosphatase (PTP) inhibitor, sodium pervanadate, reversed the RES-induced downregulation of STAT5, suggesting the involvement of a PTP. Indeed, we observed that RES decreased the expression of tyrosine phosphatase SHP-1 and SHP-2; moreover, the deletion of SHP-1 and SHP-2 genes by siRNA abolished the ability of RES to inhibit STAT5 activation, which suggested the critical role of both SHP-1 and SHP-2 in its possible mechanism of action. RES downregulated the expression of STAT5-regulated gene products such as Bcl-xL, Bcl-2, Cyclin D1, and Mcl-1, and increased the expression of Bax. This correlated with the suppression of proliferation and induction of apoptosis. Overall, our results suggest that RES is a blocker of STAT5 activation and thus may be potentially useful for the treatment of CML.

Formaldehyde induces the apoptosis of BMCs of BALB/c mice via the PTEN/PI3K/Akt signal transduction pathway

The International Agency for Research on Cancer has classified formaldehyde (FA) as a leukemogen to humans in 2012; however, the underlying mechanism remains unclear. Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) is a tumor‑suppressor gene and can negatively regulate the phosphoinositide 3‑kinase (PI3K)/protein kinase B (Akt) signal transduction pathway, which is associated with cell proliferation, apoptosis and carcinogenesis. To determine the association between FA and the PTEN/PI3K/Akt signal transduction pathway, flow cytometry, reverse transcription‑quantitative polymerase chain reaction, western blotting and immunohistochemical analysis were conducted. Bone marrow cells were obtained from BALB/c mice, divided into the control (untreated cells) and FA groups, which were treated with various doses of FA (50, 100 and 200 µmol/l). Following treatment with FA for 24 h, cell viability, the cell cycle, apoptosis, and the expression of PTEN, PI3K and Akt, as well as the protein expression of B‑cell lymphoma 2 (Bcl‑2), Bcl‑2‑associated X (Bax), and Caspases‑3 and ‑9 were examined. Furthermore, 10 µmol/PI3K inhibitor (LY294002) was applied to inhibit the PTEN/PI3K/Akt signal transduction pathway and 100 µmol/l FA was selected for treatment; alteration in the cell cycle were analyzed. The results demonstrated that FA could suppress cell viability, and downregulate PTEN and Bcl‑2; the expression of PI3K, Akt, Bax, and Caspases‑3 and ‑9 were upregulated. Additionally, FA was reported to induce cell cycle arrest at the G0/G1 phase and apoptosis. Following the application of LY294002 to inhibit the PTEN/PI3K/Akt signal transduction pathway, the numbers of cells arrested in the G0/G1 phase were significantly increased in the PI3K inhibitor group compared with the control (P<0.01); however, no significant change in the number of G0/G1 cells compared with FA group was observed (P>0.05). The results of the present study suggested that the PTEN/PI3K/Akt signal transduction pathway served an important role in the process of FA‑induced apoptosis, which may be associated with regulating the cell cycle; thus, cell proliferation may be affected.

Resveratrol Action on Lipid Metabolism in Cancer

Cancer diseases have the leading position in human mortality nowadays. The age of oncologic patients is still decreasing, and the entire scientific society is eager for new ways to fight against cancer. One of the most discussed issues is prevention by means of natural substances. Resveratrol is a naturally occurring plant polyphenol with proven antioxidant, anti-inflammatory, and anticancer effects. Tumor cells display specific changes in the metabolism of various lipids. Resveratrol alters lipid metabolism in cancer, thereby affecting storage of energy, cell signaling, proliferation, progression, and invasiveness of cancer cells. At the whole organism level, it contributes to the optimal metabolism extent with respect to the demands of the organism. Thus, resveratrol could be used as a preventive and anticancer agent. In this review, we focus on some of the plethora of lipid pathways and signal molecules which are affected by resveratrol during carcinogenesis.

Increased CDKL3 expression predicts poor prognosis and enhances malignant phenotypes in esophageal squamous cell carcinoma

BACKGROUND

Cyclin-dependent kinase-like 3 (CDKL3) is a putative protein serine kinase and plays an important role in the regulation of cell growth and/or differentiation. However, studies on the function of CDKL3 in esophageal squamous cell carcinoma (ESCC) is limited. In our study, we explored the role and prognosis of CDKL3 in ESCC and underlying mechanism.

MATERIALS AND METHODS

The expression of CDKL3 was investigated by quantitative reverse transcription polymerase chain reaction and immunohistochemical staining. CDKL3 expression was downregulated by the RNAi-mediated knockdown. The functions of CDKL3 on cell growth were assessed by Celigo image cytometry, MTT assay, cell-cycle analysis, Annexin V assay, and caspase-3/7 activity analysis. The effect of CDKL3 on cellular invasive was investigated by the Transwell assay. Pathscan Stress Signaling Antibody Array was used to study the underlying mechanism. Additionally, the association between the survival and CDKL3 expression in ESCC were evaluated based on the TCGA data.

RESULTS

CDKL3 was highly expressed in ESCC tissues and cell lines. TE-1 cells transfected with CDKL3-shRNA-lentivirus significantly decreased CDKL3 expression and resulted in inhibiting cell proliferation, inducing the S-phase cell-cycle arrest, attenuating cellular invasive and increasing cell apoptosis. The expression of pERK1/2, p-Akt, p-Smad2, p-p38 mitogen-activated protein kinase, cleaved caspase-7, and phospho-Chk1 were significantly decreased by CDKL3 knockdown. In addition, high expression of CDKL3 was associated with shorter overall survival.

CONCLUSION

Our findings suggest that higher expression of CDKL3 is correlated with poor prognosis in patients with ESCC and play a vital role in the malignant phenotype of ESCC cell lines, which indicating that CDKL3 may be as a new therapeutic target in ESCC.

AKT as a Therapeutic Target for Cancer

Many cellular processes in cancer are attributed to kinase signaling networks. V-akt murine thymoma viral oncogene homolog (AKT) plays a major role in the PI3K/AKT signaling pathways. AKT is activated by PI3K or phosphoinositide-dependent kinases (PDK) as well as growth factors, inflammation, and DNA damage. Signal transduction occurs through downstream effectors such as mTOR, glycogen synthase kinase 3 beta (GSK3β), or forkhead box protein O1 (FOXO1). The abnormal overexpression or activation of AKT has been observed in many cancers, including ovarian, lung, and pancreatic cancers, and is associated with increased cancer cell proliferation and survival. Therefore, targeting AKT could provide an important approach for cancer prevention and therapy. In this review, we discuss the rationale for targeting AKT and also provide details regarding synthetic and natural AKT-targeting compounds and their associated studies.

Resveratrol suppresses the invasion and migration of human gastric cancer cells via inhibition of MALAT1-mediated epithelial-to-mesenchymal transition

Resveratrol, a natural polyphenolic phytoalexin, was reported to exert multiple anticancer effects as a traditional Chinese medicine. However, research regarding the anticancer mechanism of resveratrol for the treatment and prevention of gastric cancer has reported conflicting results. In the present study, it was determined that resveratrol inhibited cell viability in a dose-dependent manner in the human gastric cancer cell line BGC823. Cell migration and invasion were suppressed significantly following treatment with 200 µM resveratrol. Additionally, resveratrol inhibited metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) expression, which was overexpressed in gastric cancer cells. Further experiments revealed that MALAT1 knockdown suppressed cell viability, migration, invasion and epithelial-to-mesenchymal transition in BGC823 cells. The present study indicated that resveratrol inhibited migration and invasion in human gastric cancer cells via suppressing MALAT1-mediated epithelial-to-mesenchymal transition, providing novel evidence for understanding the anticancer mechanism of resveratrol.

Crosstalk between Phosphoinositide 3-kinase/Akt signaling pathway with DNA damage response and oxidative stress in cancer

The phosphatidylinositol 3-kinases (PI3K)/Akt signaling pathway is one of the well-characterized and most important signaling pathways activated in response to DNA damage. This review discusses the most recent discoveries on the involvement of PI3K/Akt signaling pathway in cancer development, as well as stimulation of some important signaling networks involved in the maintenance of cellular homeostasis upon DNA damage, with an exploration of how PI3K/Akt signaling pathway contributes to the regulation of modulators and effectors underlying DNA damage response, the intricate, protein-based signal transduction network, which decides between cell cycle arrest, DNA repair, and apoptosis, the elimination of irreparably damaged cells to maintain homeostasis. The review continues by looking at the interplay between cell cycle checkpoints, checking the repair of damage inflicted to the DNA before entering DNA replication to facilitate DNA synthesis, and PI3K/Akt signaling pathway. We then investigate the challenges the cells overcome to ameliorate damages induced by oxidative activities, for example, the recruitment of many pathways and factors to maintain integrity and hemostasis. Finally, the review provides a discussion of how cells use the PI3K/Akt signaling pathway to regulate the balance between these networks.

MIIP is downregulated in gastric cancer and its forced expression inhibits proliferation and invasion of gastric cancer cells in vitro and in vivo

Background

MIIP is associated with cancer progression in various cancers. However, its expression pattern, and associated molecular mechanisms in gastric cancer (GC) progression are still mysterious. We aimed to explore the role of MIIP in proliferation and invasion of GC.

Materials and methods

MIIP expression was evaluated in human GC tissues and cell lines. Public clinical database of GC patients was used to probe the correlation between MIIP expression and prognosis of patients. The effects of forced MIIP expression on GC cells were determined by MTT, cell cycle distribution, colony formation, wound-healing and Transwell assays in vitro, as well as in vivo growth of subcutaneous tumor xenografts and metastasis of xenografted tumors to the lungs in mice. The expressions of GC progression-associated genes, including HOTAIR, MALAT1, HDAC6, AC-tubulin, and cyclin D1, were assessed by Western blotting or qRT-PCR.

Results

Both GC tissues and GC cell lines had lower MIIP expression. Higher level of MIIP in GC tissues predicts better survival in patients. Ectopic expression of MIIP in GC cell lines BGC823 and HGC27 induced G₀/G₁ cell cycle arrest and inhibited cell proliferation, colony formation, migration and invasion in vitro, as well as the growth of GC xenografts and metastasis of tumors in vivo. Furthermore, overexpression of MIIP suppressed mRNA expressions of HOTAIR and MALAT1, decreased protein expression of HDAC6 and cyclin D1, and elevated AC-tubulin protein expression.

Conclusion

MIIP is a suppressor for GC progression and is a potential therapeutic target for treating GC.

Pectolinarigenin inhibits non‑small cell lung cancer progression by regulating the PTEN/PI3K/AKT signaling pathway

Lung cancer is the principal cause of cancer-associated mortality. Pectolinarigenin (Pec) reportedly has effective antitumor activity against certain cancer types. Phosphatase and tensin homolog (PTEN) is a well-known tumor suppressor and serves a vital role in cancer progression. However, the effect of Pec on non-small cell lung cancer (NSCLC) cell proliferation and metastasis, and the underlying mechanism, has not yet been elucidated. In the present study, it was demonstrated that Pec inhibited the proliferation of A549 and Calu-3 cells in dose- and time-dependent manners. The apoptosis rate significantly increased with increasing doses of Pec. Apoptosis-associated protein expression was additionally altered by Pec exposure. Pec was able to suppress the metastasis of NSCLC cells; it upregulated the mRNA and protein expression levels of E-cadherin, and downregulated the mRNA and protein expression levels of vimentin. Additionally, Pec was able to activate PTEN and subsequently downregulate the PI3K/protein kinase B (AKT) signaling pathway. In summary, Pec was able to inhibit cell proliferation, promote apoptosis and suppress metastasis in NSCLC cells through the PTEN/PI3K/AKT signaling pathway, indicating that Pec is a potential agent for NSCLC therapy.

Acquired Resilience: An Evolved System of Tissue Protection in Mammals

This review brings together observations on the stress-induced regulation of resilience mechanisms in body tissues. It is argued that the stresses that induce tissue resilience in mammals arise from everyday sources: sunlight, food, lack of food, hypoxia and physical stresses. At low levels, these stresses induce an organised protective response in probably all tissues; and, at some higher level, cause tissue destruction. This pattern of response to stress is well known to toxicologists, who have termed it hormesis. The phenotypes of resilience are diverse and reports of stress-induced resilience are to be found in journals of neuroscience, sports medicine, cancer, healthy ageing, dementia, parkinsonism, ophthalmology and more. This diversity makes the proposing of a general concept of induced resilience a significant task, which this review attempts. We suggest that a system of stress-induced tissue resilience has evolved to enhance the survival of animals. By analogy with acquired immunity, we term this system 'acquired resilience'. Evidence is reviewed that acquired resilience, like acquired immunity, fades with age. This fading is, we suggest, a major component of ageing. Understanding of acquired resilience may, we argue, open pathways for the maintenance of good health in the later decades of human life.

Fresh red raspberry phytochemicals suppress the growth of hepatocellular carcinoma cells by PTEN/AKT pathway

The red raspberry (Rubus idaeus L.) is a common fruit worldwide and its extract has been found to inhibit the growth of many types of tumors, mainly because it is rich in bioactive phytochemicals. However, the mechanism underlying its anticancer activity in hepatocellular carcinoma (HCC) is not well understood. Herein, the aim of this study was to determine the effects of red raspberry phytochemicals on the proliferation of hepatocellular carcinoma cells and to elucidate its biochemical and molecular targets. CCK8 and colony formation, as well as flow cytometry assays, were employed to determine the effects of red raspberry extract (RRE) on cell proliferation and cell cycle distribution in HCC cells. Our results showed that RRE significantly inhibited cell proliferation and arrested cell cycle progression at the S phase in HCC cells. RRE increased the expression of phosphatase and tensin homologue deleted on chromosome 10 (PTEN) by reducing the methylation status of the PTEN gene promoter and inhibiting DNMT1 expression and regulated AKT signaling pathway. These findings show that red raspberry phytochemicals inhibit the proliferation of HCC cells by regulating PTEN/AKT signaling pathway, providing evidence that RRE may be used as a potential auxiliary therapy for patients with HCC.

Resveratrol inhibits the proliferation of A549 cells by inhibiting the expression of COX-2

Purpose

The aim was to investigate resveratrol effects on A549 cells proliferation.

Methods

A total of 104 lung adenocarcinoma tissues and nontumor tissues were collected. BEAS-2B cells were cultured in RPMI 1640 medium (group A). A549 cells were treated with RPMI 1640 medium containing different resveratrol concentrations. A549 cells were transfected and grouped as follows: blank group, siRNA-negative control group, siRNA-COX-2 group and resveratrol + siRNA-COX-2 group. qRT-PCR and Western blot were conducted to detect COX-2 expression. MTT assay, soft agar clone assay and flow cytometry were performed to assess proliferation and cell cycle.

Results

The relative expression of COX-2 mRNA was significantly increased in lung adenocarcinoma tissues (P<0.01) and it was closely related with clinical stages. Resveratrol at 60 μmol/L significantly inhibited A549 cells proliferation, S phase cells proportion and COX-2 expression (P<0.01). COX-2 expression in siRNA-COX-2 group was significantly lower than that in blank group and siRNA-negative control group (P<0.01). OD₅₇₀ values, colony formation rate and S phase cells proportion of resveratrol + siRNA-COX-2 group were much lower than those of other groups (P<0.01).

Conclusion

Resveratrol inhibits A549 cells proliferation by inhibiting COX-2 expression.

Matrine inhibits the invasive and migratory properties of human hepatocellular carcinoma by regulating epithelial‑mesenchymal transition

Matrine has been reported to be an effective anti-tumor therapy; however, the anti-metastatic effects of matrine on hepatocellular carcinoma (HCC) and the molecular mechanism(s) involved remain unclear. Therefore, the aims of the present study were to evaluate the effects of matrine on hepatoma and to determine the associated mechanism(s) involved. In the present study, matrine was confirmed to prevent the proliferation of HCC cells and it was observed that matrine also inhibited the migratory, and invasive capabilities of HCC at non-toxic concentrations. Additionally, matrine increased epithelial-cadherin expression and decreased the expression levels of vimentin, matrix metalloproteinase (MMP)2, MMP9, zinc finger protein SNAI1 and zinc finger protein SNAI2. These results indicate that the anti-metastatic effect of matrine may be associated with epithelial-mesenchymal transition (EMT). Furthermore, matrine can increase phosphatidylinositol 3,4,5-trisphosphate 3-phosphatase and dual-specificity protein phosphatase PTEN (PTEN) expression and reduce phosphorylated-protein kinase B (Akt) levels. In conclusion, these results suggested that matrine is a potential therapeutic agent that can suppress cancer-associated invasion and migration via PTEN/Akt-dependent inhibition of EMT.

Resveratrol induced apoptosis in human gastric carcinoma SGC-7901 cells via activation of mitochondrial pathway

BACKGROUND

Resveratrol is a natural polyphenolic compound and its anticancer effect has been receiving considerable attention. Previous studies showed that resveratrol could inhibited the growth of human gastric carcinoma cells and apoptosis induction was an important mechanism. However, whether mitochondrial pathway was involved in resveratrol-induced apoptosis in human gastric cancer was not very clear.

METHODS

The cells were examined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, Annexin V/PI staining assay, mitochondrial membrane depolarization, cell morphological assessment, cytochrome c release assay, and Western blotting assay.

RESULTS

In this study, we found that resveratrol induced apoptosis in human gastric carcinoma SGC-7901 cells. Cleaved PARP was observed and caspase-3 was activated by resveratrol. Next, the mitochondrial membrane potential of cells dissipated after the cells were treated by resveratrol. Moreover, we found that pro-caspase 9 was downregulated and cytochrome c released from mitochondrial to the cytosol. We also found that the expression ratio of Bax/Bcl-2 was increased in the treated cells. We finally showed that resveratrol inhibited the proliferation of SGC-7901 xerograph in vivo.

CONCLUSIONS

Collectively, our findings demonstrate that resveratrol triggers apoptosis via mitochondrial pathway in SGC-7901 cells, which provide more basis for resveratrol acting as antitumor agents in cancer therapy.

MicroRNA-28 promotes cell proliferation and invasion in gastric cancer via the PTEN/PI3K/AKT signalling pathway

Gastric cancer is the fourth most common malignant disease and second leading cause of cancer‑associated mortalities worldwide. Previous studies revealed aberrantly expressed microRNAs (miRNAs) in various types of human cancer; these miRNAs play important roles in tumourigenesis and tumour development. miRNAs present a considerable potential for novel therapeutic approaches for treating human cancer. Therefore, the investigation of novel miRNAs involved in gastric cancer progression provides an opportunity to improve the prognosis of patients with gastric cancer. miRNA‑28 (miR‑28) has been investigated with regards to its expression and biological functions in many types of human cancer. However, previous studies have not discussed the expression patterns, roles and associated molecular mechanisms of miR‑28 in gastric cancer. In the present study, miR‑28 expression was identified to be upregulated in gastric cancer tissues and cell lines. miR‑28 inhibition functionally inhibited cell proliferation and invasion in gastric cancer in vitro. Using bioinformatics analysis, luciferase reporter assay, reverse transcription‑quantitative polymerase chain reaction and western blot analysis, phosphatase and tensin homolog (PTEN) was mechanically identified as a direct target of miR‑28 in gastric cancer. PTEN was downregulated in gastric cancer and negatively correlated with miR‑28 levels. Inhibition of PTEN restored the biological effects of miR‑28 downregulation on the proliferation and invasion of gastric cancer cells. Notably, the downregulation of miR‑28 results in the regulation of the phosphatidylinositol 3‑kinase/protein kinase B signaling pathway in gastric cancer. These results suggested that miR‑28 may be targeted for the development of novel treatments for gastric cancer in the future.

Phytochemicals and PI3K Inhibitors in Cancer-An Insight

In today's world of modern medicine and novel therapies, cancer still remains to be one of the prime contributor to the death of people worldwide. The modern therapies improve condition of cancer patients and are effective in early stages of cancer but the advanced metastasized stage of cancer remains untreatable. Also most of the cancer therapies are expensive and are associated with adverse side effects. Thus, considering the current status of cancer treatment there is scope to search for efficient therapies which are cost-effective and are associated with lesser and milder side effects. Phytochemicals have been utilized for many decades to prevent and cure various ailments and current evidences indicate use of phytochemicals as an effective treatment for cancer. Hyperactivation of phosphoinositide 3-kinase (PI3K) signaling cascades is a common phenomenon in most types of cancers. Thus, natural substances targeting PI3K pathway can be of great therapeutic potential in the treatment of cancer patients. This chapter summarizes the updated research on plant-derived substances targeting PI3K pathway and the current status of their preclinical studies and clinical trials.

Resveratrol-mediated apoptosis in renal cell carcinoma via the p53/AMP‑activated protein kinase/mammalian target of rapamycin autophagy signaling pathway

Resveratrol, known as phytoalexin, is a natural compound. Clinical studies have revealed that resveratrol has a variety of effects including anti‑inflammatory, antivirus and tumor suppressor activities. It has been reported that it may serve an important role in renal cell carcinoma (RCC) however, the molecular mechanism underlying resveratrol‑induced apoptosis in RCC is still unclear. The aim of the present study was to determine whether resveratrol could suppress RCC progression. Analysis of apoptosis demonstrated that resveratrol may act as a RCC suppressor in a dose‑ and time‑dependent manner. In addition, the results of the MTT and cell migration experiments revealed that resveratrol significantly decreased cell viability and migration. In addition, the expression of the anti‑apoptosis gene B‑cell lymphoma 2 (Bcl‑2) was downregulated by resveratrol, and the expression of pro‑apoptosis gene Bcl‑2‑associated X was upregulated at the mRNA and protein levels. Resveratrol also promoted the expression of p53 and activated phospho‑AMP‑activated protein kinase (AMPK). The phosphorylation of mammalian target of rapamycin (mTOR) was inhibited and the autophagy‑associated genes, light chain 3, autophagy related (ATG)5 and ATG7, were upregulated at the mRNA and protein levels. In conclusion, resveratrol suppressed RCC viability and migration, and promoted RCC apoptosis via the p53/AMPK/mTOR‑induced autophagy signaling pathway.

Downregulation of MicroRNA-147 Inhibits Cell Proliferation and Increases the Chemosensitivity of Gastric Cancer Cells to 5-Fluorouracil by Directly Targeting PTEN

Gastric cancer is the fourth most common malignancy and the third leading cause of cancer-related deaths worldwide. This study aimed to investigate the expression patterns, biological roles, and underlying mechanisms of microRNA-147 (miR-147) in gastric cancer. The present study demonstrated that miR-147 was significantly upregulated in gastric cancer tissues and cell lines. Downregulation of miR-147 decreased cell proliferation and enhanced the chemosensitivity of gastric cancer cells to 5-fluorouracil (5-FU) through the cell apoptosis pathway. In addition, phosphatase and tensin homolog (PTEN) was mechanically identified as the direct target of miR-147 in gastric cancer. PTEN knockdown reversed the effects of miR-147 downregulation on the proliferation, chemosensitivity, and 5-FU-induced apoptosis of gastric cancer cells. Moreover, miR-147 regulated the PI3K/AKT signaling pathway in gastric cancer by targeting PTEN. In conclusion, miR-147 suppressed the proliferation and enhanced the chemosensitivity of gastric cancer cells to 5-FU by promoting cell apoptosis through directly targeting PTEN and regulating the PI3K/AKT signaling pathway. This study provides important insight into the molecular mechanism that underlies the chemoresistance of gastric cancer cells. The results of this study could aid the development of a novel therapeutic strategy for gastric cancer.