Cinobufacin suppresses cell proliferation via miR-494 in BGC- 823 gastric cancer cells

Cinobufacini enhances the therapeutic response of 5-Fluorouracil against gastric cancer by targeting cancer stem cells via AKT/GSK-3β/β-catenin signaling axis

BACKGROUND

Gastric cancer stem cells (GCSCs) play crucial role in the development, recurrence, and resistance of gastric cancer (GC). Cinobufacini, a traditional Chinese medicine, offers significant advantages in improving tumor therapy. However, pre-clinical investigation into the antitumor effect and mechanism of Cinobufacini on GC is still lacking. Additionally, it has not been reported whether Cinobufacini is related to cancer stem cells (CSCs).

METHODS

The CCK-8, clone formation, EdU staining, transwell and wound healing experiments were performed to assess the cell toxicity of Cinobufacini and demonstrate the preventive effects of Cinobufacini on proliferation, invasion, and migration of GC cells. Elucidating the underlying mechanism of Cinobufacini in GC based on the transcriptome sequencing. Flow cytometry assays, sphere formation assays, subcutaneous xenograft model in nude mice, and immunofluorescent staining have been used to investigate whether the anti-GC effect of Cinobufacini is associated with GCSCs and enhancing therapeutic response to 5-Fluorouracil (5-FU).

RESULTS

Cinobufacini exerts minimal impact on normal human gastric epithelium cell GES-1, while significantly suppressing the proliferation, invasion, and migration of GC cell lines. Additionally, Cinobufacini attenuates the stemness of GCSCs by disrupting the AKT/GSK-3β/β-catenin signaling cascade. Moreover, Cinobufacin enhances the anti-tumor effects of 5-FU against GCSCs by reducing in vitro sphere formation and inhibiting subcutaneous graft tumor growth in vivo.

CONCLUSIONS

Cinobufacini enhances the therapeutic response of 5-FU against GC by targeting CSCs via AKT/GSK-3β/β-catenin signaling axis. Our findings offer a crucial insight into the molecular mechanism of Cinobufacini's anticancer activity in GC.

Regulatory Mechanism and Experimental Verification of Patchouli Alcohol on Gastric Cancer Cell Based on Network Pharmacology

Background

Pogostemon cablin is a traditional Chinese medicine (TCM) that is frequently used to treat various gastrointestinal diseases. Patchouli alcohol (PA), a compound extracted from the Pogostemon cablin, has been shown to have anti-tumor efficacy in human colorectal cancer. However, the mechanism of PA’s anticancer effect on gastric cancer (GC) remains unknown.

Methods

We used the public database to obtain the potential targets of PA and genes related to GC. Bioinformatic analyses, such as the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and protein-protein interactions (PPI), were used for analyzing the potential signal pathways and targets. Cell experiments were also conducted to further explain the impact and molecular mechanism of PA on GC, as well as to confirm the findings of network pharmacology.

Results

Using network pharmacological analysis, 161 possible targets were identified for the treatment of GC. Network analysis and functional enrichment analysis show that PA produced a marked effect in the treatment of GC through multi-targets and multi-pathways, especially the MAPK and PI3K/AKT signal pathways. In addition, PA showed the inhibition of GC cell proliferation, migration and invasion in cell experiments. According to our findings, PA could also cause G0/G1 phase arrest and apoptosis in GC cells.

Conclusion

Using network pharmacology, we aim to uncover the possible molecular mechanism of PA on GC treatment in this research. Cell experiments were also conducted to confirm the therapeutic effect of PA on GC.

MiR-494-mediated Effects on the NF-κB Signaling Pathway Regulate Lipopolysaccharide-Induced Acute Kidney Injury in Mice

OBJECTIVE

To explore the effects of miR-494 inhibition through the NF-κB signaling pathway on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) mouse model.

METHODS

The AKI mice induced by LPS were treated with miR-494 antagomir, and the kidney parameters and indicators of oxidative stress were detected. HE and TUNEL staining were performed to observe the kidney histopathology and the apoptosis in renal tubular epithelial cells (RTECs), respectively. The ROS level was measured using dihydroethidium (DHE) staining. In addition, qRT-PCR, western blotting, immunohistochemistry (IHC), and ELISA were also used to detect gene or protein expression.

RESULTS

LPS-induced AKI mice injected with the miR-494 antagomir showed reduced blood urea nitrogen (BUN) and serum creatinine (Cr) with improved kidney histopathology. The expression levels of p-IKKα/β, p-IκBα and p65 NF-κB in the nucleus were increased in kidney tissues from the LPS-induced AKI mice, and they were decreased by the miR-494 antagomir. Moreover, the results of IHC showed that the miR-494 antagomir downregulated p65 NF-κB in kidney tissues from the LPS-induced AKI mice, accompanied by decreased levels of TNF-α, IL-1β, IL-6, MDA, NO, and ROS but increased levels of SOD and GSH. In addition, the LPS-induced AKI mice had increased apoptosis in RTECs, as well as increased Caspase-3 and Bax and decreased Bcl-2, which were reversed by the miR-494 antagomir.

CONCLUSIONS

The inhibition of miR-494 could reduce inflammatory responses and improve oxidative stress in kidney tissues from LPS-induced AKI mice by blocking the NF-κB pathway accompanying by reduced apoptosis in RTECs.

Histone Modifier Differentially Regulates Gene Expression and Unravels Survival Role of MicroRNA-494 in Jurkat Leukemia

BACKGROUND

Although the protein-coding genes are subject to histone hyperacetylation-mediated regulation, it is unclear whether microRNAs are similarly regulated in the T cell leukemia Jurkat.

OBJECTIVE

To determine whether treatment with the histone modifier Trichostatin A could concurrently alter the expression profiles of microRNAs and protein-coding genes.

METHODS

Changes in histone hyperacetylation and viability in response to drug treatment were analyzed, respectively, using western blotting and flow cytometry. Paired global expression profiling of microRNAs and coding genes was performed and highly regulated genes validated by qRT-PCR. The interrelationships between the drug-induced miR-494 upregulation, the expression of putative target genes, and T cell receptor-mediated apoptosis were evaluated using qRT-PCR, flow cytometry, and western blotting following lipid-mediated transfection with specific anti-microRNA inhibitors.

RESULTS

Treatment of Jurkat cells with Trichostatin A resulted in histone hyperacetylation and apoptosis. Global expression profiling indicated prominent upregulation of miR-494 in contrast to differential regulation of many protein-coding and non-coding genes validated by qRT-PCR. Although transfection with synthetic anti-miR-494 inhibitors failed to block drug-induced apoptosis or miR-494 upregulation, it induced the transcriptional repression of the PVRIG gene. Surprisingly, miR-494 inhibition in conjunction with low doses of Trichostatin A enhanced the weak T cell receptor-mediated apoptosis, indicating a subtle pro-survival role of miR-494. Interestingly, this pro-survival effect was overwhelmed by mitogen-mediated T cell activation and higher drug doses, which mediated caspase-dependent apoptosis.

CONCLUSION

Our results unravel a pro-survival function of miR-494 and its putative interaction with the PVRIG gene and the apoptotic machinery in Jurkat cells.

Research Progress in microRNA-Based Therapy for Gastric Cancer

Gastric cancer (GC) is one of the leading causes of tumor-related mortality. In addition to surgery and endoscopic resection, systemic therapy remains the main treatment option for GC, especially for advanced-stage disease and for cases not suitable for surgical therapy. Hence, improving the efficacy of systemic therapy is still an urgent problem to overcome. In the past decade, the essential roles of microRNAs (miRNAs) in tumor treatment have been increasingly recognized. In particular, miRNAs were recently shown to reverse the resistance to chemotherapy drugs such as 5-fluorouracil, cisplatin, and doxorubicin. Synthesized nanoparticles loaded with mimics or inhibitors of miRNAs can directly target tumor cells to suppress their growth. Moreover, exosomes may serve as promising safe carriers for mimics or inhibitors of miRNAs to treat GC. Some miRNAs have also been shown to play roles in the mechanism of action of other anti-tumor drugs. Therefore, in this review, we highlight the research progress on microRNA-based therapy in GC and discuss the challenges and prospects associated with this strategy. We believe that microRNA-based therapy has the potential to offer a clinical benefit to GC patients, and this review would contribute to and motivate further research to promote this field toward this ultimate goal.

Analysis of potential functional significance of microRNA‑3613‑3p in human umbilical vein endothelial cells affected by heat stress

Dysregulation of microRNA‑3613‑3p (miR‑3613‑3p) was previously reported in endothelial cells (ECs) during heat stress. The aim of the present study was to investigate the precise role of miR‑3613‑3p in heat stress. In the present study, potential gene targets of miR‑3613‑3p in heat‑treated ECs were assessed, and the potential effects of miR‑3613‑3p were determined using Gene Ontology enrichment analysis. Kyoto Encyclopedia of Genes and Genomes pathway analysis was used to identify signaling pathways that may be affected by miR‑3613‑3p in heat‑treated cells. Reverse transcription‑quantitative PCR, western blotting and annexin V‑FITC/propidium iodide staining were performed to detect miRNA expression, protein expression and apoptosis, respectively. Luciferase gene reporter assay was performed to evaluate the association between miR‑3613‑3p and mitogen‑activated protein kinase kinase kinase 2 (MAP3K2). Bioinformatics analysis revealed 865 potential gene targets for miR‑3613‑3p and a series of functions and pathways in heat‑treated ECs. 'Negative regulation of apoptotic process' was identified as a potential function of miR‑3613‑3p. In addition, functional analysis confirmed the downregulated expression levels of miR‑3613‑3p in ECs during heat stress, which was accompanied by an increase in apoptosis; restoration of miR‑3613‑3p expression inhibited apoptosis. MAP3K2 protein was demonstrated to be upregulated in heat‑treated ECs, and overexpression of miR‑3613‑3p reduced MAP3K2 expression levels. Additionally, MAP3K2 was targeted by miR‑3613‑3p. These results indicated that miR‑3613‑3p may have complicated roles in ECs under heat stress. miR‑3613‑3p may serve an important role in the apoptosis of heat‑treated ECs, and this effect may be partly achieved by targeting MAP3K2.

Bufothionine exerts anti-cancer activities in gastric cancer through Pim3

AIM

Gastric cancer (GC) is the fourth most common cancer globally. Bufothionine is a major active constituent of Cinobufacini (Huachansu), which is extracted from the skin and parotid venom gland of the toad Bufo bufo gargarizans Cantor. It exhibits anti-cancer activities in vitro. However, whether bufothionine exerts anti-cancer activities against GC is unknown. This study was designed to evaluate the efficacy of bufothionine in vitro and in vivo.

MATERIAL AND METHODS

MKN28 and AGS cells were chosen as cell models to study the anti-cancer effect of bufothionine. Cell viability was determined by CCK-8 assay, while the effect of bufothionine on cell membrane integrity was examined by LDH assay. Cell apoptosis was detected by Hoechst/PI staining and Annexin V-FITC/PI staining followed by flow cytometry analysis. The expression levels of proteins involved were examined using western blotting. I-Traq analysis was conducted to identify the differentially expressed genes in AGS cells following bufothionine treatment. The anti-growth effect of bufothionine was validated in vivo using a GC xenograft model.

KEY FINDINGS

The results revealed that bufothionine prevented the growth, destroyed cell membrane and promoted apoptotic cell death of GC cells. iTRAQ analysis revealed thatPIM3 might be a molecular target responsible for the anti-cancer effects of bufothionine. It was also found that PIM3 knockdown significantly augmented the anti-growth and pro-apoptotic effects of bufothionine in GC cells. In contrast, ectopic PIM3 expression markedly dampened the anti-neoplastic activities of bufothionine. The expression of PIM3 was also suppressed by bufothionine treatment in xenograft tumor tissue.

SIGNIFICANCE

Bufothionine exhibited anti-cancer activities in vitro and in vivo in GC via downregulating PIM3.

miR-494 induces EndMT and promotes the development of HCC (Hepatocellular Carcinoma) by targeting SIRT3/TGF-β/SMAD signaling pathway

EndMT has an important effect on metastasis and progression of tumor. This work will elucidate the effect of miR-494 on EndMT and development of HCC. Therefore, the differential miRNA expression among non-tumorous, para-tumorous and tumorous tissues was analyzed. Moreover, luciferase activities of SIRT3 3′UTR treated with miR-494 were determined. Then human hepatoma cell lines were dealt with mimics or inhibitors of miR-494, migration and proliferation ability were assessed. The expression of SIRT3 and markers of mesenchymal cell were analyzed. The influences of miR-494 on development of HCC through inducing EndMT by targeting SIRT3 and TGF-β/SMAD signaling pathways in hepatoma cell lines were investigated. Xenograft mice were used to explore the potential roles of miR-494 on EndMT and development of HCC in vivo. Our results showed that, compared with non-tumorous tissues, 17 miRNAs were upregulated and 3 miRNAs were down-regulated in tumor tissues. In tumor tissues, the miR-494 expression level was much more than the expression of para-tumorous and non-tumorous tissues. MiR-494 suppressed SIRT3 expression, additionally enhanced expression of mesenchymal cell markers, while exerted effects on cell proliferation and migration of hepatoma cell lines. Moreover, the antagomir of miR-494 could protect against development process in xenogarft murine model. In conclusions, our work demonstrated that miR-494 targeted to SIRT3, and was a crucial mediator of EndMT and development of HCC through regulating SIRT3/TGF-β/SMAD signaling pathway. It suggested that aim at SIRT3/TGF-β/SMAD signaling pathway through suppressing the miR-494 expression level, was a feasible therapy strategy for HCC.

Cinobufacini Injection Improves the Efficacy of Chemotherapy on Advanced Stage Gastric Cancer: A Systemic Review and Meta-Analysis

Gastric cancer has a high morbidity and mortality. Chemotherapy regimens are routine advanced stage gastric cancer (AGC) treatment protocols, but most of these drugs have side-effects such as myelosuppression and gastrointestinal disorders. Cinobufacini, an extractive from TCM, could suppress cell proliferation and inhibit gastric cancer. In this study, we comprehensively reviewed the literature on the efficacy comparison between Cinobufacini injection combined with chemotherapy and chemotherapy solely used in AGC treatment. We extracted data for from six electronic databases to evaluate the efficacy of Cinobufacini injection on AGC patients. Twelve studies with a total of 853 patients were finally included in our study. The results indicated that Cinobufacini injection could increase response rate and disease control rate of chemotherapy on AGC, improve the life quality of AGC patients, increase leukocytes, improve anemia, improve hand-foot syndrome induced by chemotherapy, and relieve cancer pain. This study has its own limitations that prevented us from drawing a definite conclusion and more well-designed clinical trials of TCM are needed.

miR‑494‑BAG‑1 axis is involved in cinobufacini‑induced cell proliferation and apoptosis in gastric cancer

Cinobufacini is widely used in the treatment of advanced cancers. It has been previously reported that microRNA (miR)‑494 was upregulated in cinobufacini‑treated gastric cancer cells; however, the detailed role of miR‑494 in the anti‑tumor activity of cinobufacini is unclear. The present study aimed to clarify the function of miR‑494 in cinobufacini‑induced cell behavior changes. Cell viability and proliferation ability were investigated using a Cell Counting Kit‑8 assay. Flow cytometry was performed to investigate the apoptosis rate of gastric cancer (GC) cells. The mRNA expression levels of microRNA (miR)‑494 and BCL2 associated athanogene 1 (BAG‑1) were investigated using reverse transcription‑quantitative polymerase chain reaction, and the protein expression level of BAG‑1 was investigated using western blot assays. The results demonstrated that treatment with cinobufacini suppressed proliferation and promoted apoptosis of gastric cancer cells. miR‑494 acts as a tumor suppressor gene in gastric cancer. In cinobufacini‑treated cells, miR‑494 and BAG‑1 exhibited opposing expression trends. Furthermore, knockdown of miR‑494 in cinobufacini‑treated cells upregulated the protein expression level of BAG‑1, promoted cell proliferation and inhibited cell apoptosis. In addition, inhibition of BAG‑1 using small interfering RNA in cinobufacini‑treated cells partially abrogated the effects of miR‑494 inhibitor on cell proliferation and apoptosis. Thus, these results suggest that cinobufacini suppresses GC cells proliferation and promotes apoptosis partially through the regulation of miR‑494‑BAG‑1 axis, which may provide a novel insight into the functional mechanism of cinobufacini.

Which are the best Chinese herbal injections combined with XELOX regimen for gastric cancer?: A PRISMA-compliant network meta-analysis

BACKGROUND

The optimal Chinese herbal injections (CHIs) combined with XELOX regimen for patients with gastric cancer remains elusive. The aim of our network meta-analysis (NMA) is to explore the best options among different CHIs for gastric cancer.

METHODS

PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure Database (CNKI), Wan-fang Database, Cqvip Database (VIP), China Biology Medicine disc (CBMdisc) were searched to identify RCTs which focused on CHIs against gastric cancer. The quality assessment of included randomized controlled trials (RCTs) was conducted by the Cochrane risk of bias tool. Standard pair-wise and Bayesian NMAs were performed to compare the efficacy and safety of different CHIs combined with the XELOX regimen via Stata 13.0 and WinBUGS1.4 software.

RESULTS

A total of 2316 records were searched, the network of evidence included 26 eligible RCTs involving 13 types of CHIs and 2154 patients. The results suggested that Shenqifuzheng+ XELOX, Huachansu+ XELOX, Kangai+ XELOX, Javanica oil emulsion+ XELOX, Aidi injection+ XELOX might be the optimal treatment for gastric cancer in improving the performance status than using XELOX regimen single, with odds ratios (OR) and 95% confidence intervals (CIs) of 2.74 (1.24, 6.17), 8.27 (1.74, 42.43), 4.28 (1.80, 10.48), 5.14 (1.87, 16.28), 0.20 (0.090, 0.44). At the aspects of ADRs (adverse reactions), Compound Kushen+ XELOX, Lentinan+ XELOX, Xiaoaiping injection+ XELOX could obviously relieve leukopenia than only receiving XELOX regimen, and their ORs and 95% CIs were 5.62 (1.41, 36.24), 8.16 (2.25, 29.43), 5.69 (1.85, 15.77). Furthermore, Disodium cantharidinate and vitamin B6+ XELOX, Shenqifuzheng+ XELOX, Kangai+ XELOX, Lentinan+ XELOX could obviously relieve the nausea and vomiting than receiving the XELOX regimen alone, with ORs and 95% CIs of 5.29 (1.30, 23.96), 2.50 (1.16, 5.26), 2.42 (1.06, 5.63), 9.04 (3.24, 26.73). Nevertheless, CHIs combined with XELOX regimen did not confer higher better clinical effectiveness rate over receiving XELOX regimen alone, with nonstatistically significant between-group differences.

CONCLUSIONS

As the available evidence suggested that CHIs combined with XELOX regimen could provide treatment benefits for patients with gastric cancer. Among 13 types of CHIs, Javanica oil emulsion and Compound Kushen injection is the optimal treatment in improving the clinical effectiveness rate and performance status, and Lentinan injection was superior in relieving ADRs.

miR-494 inhibits cervical cancer cell proliferation through upregulation of SOCS6 expression

It is unclear how microRNA (miR)-494 inhibits the proliferation of cervical cancer cells by altering the expression of SOCS6. Therefore, the present study aimed to investigate the molecular mechanism underlying miR-494 regulation of suppressor of cytokine signaling 6 (SOCS6) in human cervical cancer samples and the human cervical cancer HeLa cell line. The expression of miR-494 was determined using reverse transcription-quantitative polymerase chain reaction. In addition, TargetScan was used to predict miR-494 target genes and the luciferase reporter assay was used to determine whether SOCS6 was a direct target of miR-494. The results of the present study demonstrated that compared with the cervical intraepithelial neoplasia and normal cervical tissues, the miR-494 expression level in cervical cancer samples was significantly decreased (P<0.01). In addition, compared with normal cervical tissue, miR-494 expression level was significantly decreased in cervical intraepithelial lesions (P<0.05). Furthermore, the expression of miR-494 was associated with patients with or without lymph node metastasis, clinical stage and depth of stromal invasion (P<0.01); however, miR-494 expression was not identified to be associated with age, tumor size and menopausal status (P>0.05). Transfection of a miR-494 mimic significantly increased the expression level of miR-494 in HeLa cells (P<0.01), and anti-miR-494 transfection decreased the expression of miR-494 (P<0.01). An MTT proliferation assay and Boyden chamber invasion ability assay revealed that miR-494 mimic transfection significantly inhibited the proliferation, and invasion ability of HeLa cells (P<0.01), whereas anti-miR-494 transfection significantly increased the proliferation and invasion ability (P<0.05). SOCS6 was predicted, using bioinformatics, to be the target gene of miR-494 and this was validated using a luciferase reporter assay. Western blot analysis revealed that transfection of miR-494 significantly increased the expression of SOCS6 in HeLa cells, and transfection of anti-miR-494 significantly decreased the expression of SOCS6. Therefore, the results of the present study demonstrated that miR-494 expression in cervical cancer was significantly decreased. Exhibiting a decreased expression level of miR-494 may result in enhanced proliferative and invasive abilities of HeLa cell, thus contributing to the occurrence, and development of cervical cancer.

MEG2 is regulated by miR-181a-5p and functions as a tumour suppressor gene to suppress the proliferation and migration of gastric cancer cells

BACKGROUND

Protein-tyrosine phosphatase MEG2 (MEG2) is a classic tyrosine-specific protein tyrosine phosphatase (PTP). It has been reported that MEG2 participates in the carcinogenesis of the breast and liver. However, functions of MEG2 in gastric cancer remain poorly understood.

METHODS

We examined the expression of MEG2 protein by western blotting and that of miR-181a-5p by qRT-PCR. We used bioinformatic analyses to search for miRNAs that potentially target MEG2. We performed a luciferase reporter assay to investigate the interaction between miR-181a-5p and MEG2. In addition, we assessed the effects of MEG2 and miR-181a-5p on gastric cancer cells in vitro and in vivo.

RESULTS

We found that MEG2 is downregulated in human gastric cancer and that miR-181a-5p is predicted to be a potential regulator of MEG2. We also observed that expression of MEG2 is reversely correlated with that of miR-181a-5p in gastric cancer. Moreover, we observed that MEG2 regulation by miR-181a-5p significantly suppresses the proliferation and migration of gastric cancer cells in vitro and decelerates tumour growth in vivo.

CONCLUSIONS

Our results revealed that MEG2 is a tumour suppressor gene and negatively regulated by miR-181a-5p in gastric cancer.

Overexpression of miR-15b-5p promotes gastric cancer metastasis by regulating PAQR3

Gastric cancer (GC) is the fifth most common cancer in the world, with 952,000 new cases diagnosed in 2012. Tumor metastasis is the major cause of cancer recurrence and death. miR-15b-5p has been reported to be dysregulated in numerous types of cancers. However, the role of miR-15b-5p in GC metastasis remains unclear. An miRNA microarray was adopted to analyze the miRNA expression profile. By employing quantitative real-time polymerase chain reaction (qRT-PCR), miR-15b-5p expression levels were detected in GC cell lines, tissues and plasma samples. In addition, the effects of miR-15b-5p on cell proliferation, migration and invasion were studied by applying gain-of-function approaches. Moreover, the target of miR-15b-5p was assessed by dual-luciferase assay, and the mechanism underlying the regulation of GC metastasis by miR-15b-5p was assessed by rescue experiments. The results revealed that miR-15b-5p was upregulated in GC cell lines, tissues and plasma samples. A high plasma level of miR-15b-5p was correlated with distant tumor metastasis. In addition, overexpression of miR‑15b-5p in GC cells promoted cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT). Moreover, progestin and adipoQ receptor family member 3 (PAQR3) was found to be a direct target of miR-15b-5p and re-expression of PAQR3 in miR-15b-5p-overexpressing GC cells partly attenuated the proliferation, migration and invasion. These findings revealed that miR-15b-5p promotes the metastasis of GC cells through PAQR3 and may represent a potential biomarker of GC.

Reversal of P-gp-mediated multidrug resistance in colon cancer by cinobufagin

Cinobufagin (CBF) is isolated from the skin and posterior auricular glands of the Asiatic toad (Bufo gargarizans). This study investigated the reversal effect of CBF on P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) in colon cancer. The effect of CBF on the cytotoxicity of anticancer drugs in P-gp overexpressing LoVo/ADR, HCT116/L, Cao-2/ADR cells and their parental cells was determined using CCK-8 assay. Apoptosis of anti-cancer drugs and accumulation of doxorubicin (DOX) and Rhodamine 123 (Rho123) in P-gp overexpressing cells were evaluated by flow cytometry. Results indicated that CBF significantly enhanced the sensitivity of P-gp substrate drugs on P-gp overexpressing cells, but had no effect on their parental cells. CBF enhanced the effect of DOX against P-gp-overexpressing LoVo/ADR cell xenografts in nude mice. Moreover, CBF also increased cell apoptosis of chemotherapy agents and intracellular accumulation of DOX and Rho123 in the MDR cells. Further research on the mechanisms revealed non-competitive inhibition of P-gp ATPase activity, but without altering the expression of P-gp. These findings demonstrated that CBF could be further developed into a safe and potent P-gp modulator for combination use with anticancer drugs in cancer chemotherapy.

18β-glycyrrhetinic acid suppresses gastric cancer by activation of miR-149-3p-Wnt-1 signaling

18β-glycyrrhetinic acid (GRA) exerts anti-tumor effects on various types of cancer. In the present study, we found that GRA attenuated the severity of gastritis and suppressed gastric tumorigenesis in transgenic mice. We also discovered that miR-149-3p was downregulated in gastric cancer tissues and cell lines as compared to normal gastric tissues and epithelial cells, but was upregulated by GRA. miR-149-3p expression also correlated negatively with lymphnode metastasis. Our functional assays showed that miR-149-3p overexpression inhibited cell proliferation and cell cycle progression while inducing apoptosis, while inhibition of miR-149-3p had the opposite effects. In addition, we identified Wnt-1 as a direct target of miR-149-3p. These data suggest that GRA inhibits the initiation and progression of gastric tumors by ameliorating the inflammatory microenvironment through downregulation of COX-2 expression and by inhibiting Wnt-1 expression through the upregulation of tumor suppressor miR-149-3p. GRA may thus have the potential to serve as a useful therapeutic agent for the prevention and treatment of gastric cancer.

Identification and functional characterization of the miRNA-gene regulatory network in chronic myeloid leukemia lineage negative cells

Chronic myeloid leukemia (CML) is maintained by leukemic stem cells (LSCs) which are resistant to the existing TKI therapy. Hence a better understanding of the CML LSCs is necessary to eradicate these cells and achieve complete cure. Using the miRNA-gene interaction networks from the CML lin(-) cells we identified a set of up/down-regulated miRNAs and corresponding target genes. Association studies (Pearson correlation) from the miRNA and gene expression data showed that miR-1469 and miR-1972 have significantly higher number of target genes, 75 and 50 respectively. We observed that miR-1972 induces G2-M cell cycle arrest and miR-1469 moderately arrested G1 cell cycle when overexpressed in KCL22 cells. We have earlier shown that a combination of imatinib and JAK inhibitor I can significantly bring down the proliferation of CML lineage negative cells. Here we observed that imatinib and JAK inhibitor I combination restored the expression pattern of the down-regulated miRNAs in primary CML lin(-) cells. Thus effective manipulation of the deregulated miRNAs can restore the miRNA-mRNA networks that can efficiently inhibit CML stem and progenitor cells and alleviate the disease.

Risk Factors and Epidemiology of Gastric Cancer in Pakistan

Gastric cancer is the 2nd most common cause of death among all cancers and is the 4th most common cancer in the world. The number of deaths due to gastric cancer is about 800,000 annually. Gastric cancer is more common in men as compared to women and is 3rd most common cancer after colorectal and breast cancers in women. A progressive rise in the incidence rate has been observed in females over the last 5 years. The highest incidence of stomach cancer is in China, South America and Eastern Europe. The incidence of gastric cancer has 20 fold variation worldwide. Global variation is linked by two factors which play important role in developing gastric cancer. One is infection with Helicobacter pylori and the 2nd is diet. South Asia is a region with low risk, despite a high prevalence of H.pylori. Gastric carcinoma is common in southern region of India. Gastric cancer is more readily treated if diagnosed early. This study aims to provide awareness about gastric cancer as well as an updated knowledge about risk factors and epidemiology of gastric cancer in Pakistan.

Therapeutic Potential of miR-494 in Thrombosis and Other Diseases: A Review

Functional nucleic acids, such as microRNAs (miRNAs), have been implicated in the pathophysiology of many diseases. The miRNA expression profiles of various cancers including haematological malignancies are well defined, but the role of miRNAs in haemostasis and the regulation of coagulation is poorly understood. We identified that miR-494 is oestrogen responsive and directly targets the anticoagulant protein, Protein S, as a mechanism for acquiring Protein S deficiency under high oestrogenic conditions such as during pregnancy and oral contraceptive use. Furthermore, previous studies have also characterised miR-494 to be involved in many biological processes. This paper reviews the current knowledge in the role of miRNAs in regulating haemostatic proteins and the known biological functions of miR-494, highlighting miR-494 as an emerging therapeutic target, with an overview of the strategy we have employed in identifying functional nucleic acids such as miRNAs that target haemostatic factors and the therapeutic potential of miR-494-directed therapy for the treatment of thrombotic disorders.

TRAIL based therapy: overview of mesenchymal stem cell based delivery and miRNA controlled expression of TRAIL

Rapidly increasing number of outstanding developments in the field of TRAIL mediated signaling have revolutionized our current information about inducing and maximizing TRAIL mediated apoptosis in resistant cancer cells. Data obtained with high-throughput technologies have provided finer resolution of tumor biology and now it is known that a complex structure containing malignant cells strictly coupled with a large variety of surrounding cells constitutes the tumor stroma. Utility of mesenchymal stem cells (MSCs) as cellular vehicles has added new layers of information. There is sufficient experimental evidence substantiating efficient gene deliveries into MSCs by retroviral, lentiviral and adenoviral vectors. Moreover, there is a paradigm shift in molecular oncology and recent high impact research has shown controlled expression of TRAIL in cancer cells on insertion of complementary sequences for frequently downregulated miRNAs. In this review we have attempted to provide an overview of utility of TRAIL engineered MSCs for effective killing of tumor and potential of using miRNA response elements as rheostat like switch to control expression of TRAIL in cancer cells.

MiRNA-494 inhibits metastasis of cervical cancer through Pttg1

Many cervical cancer (CC) patients experience early cancer metastasis, resulting in poor therapeutic outcome after resection of primary cancer. Hence, there is a compelling requirement for understanding of the molecular mechanisms underlying the invasiveness control of CC. Pituitary tumor-transforming gene 1 (Pttg1) has been recently reported to promote cancer cell growth and metastasis in a number of various tumors. However, its regulation by microRNAs (miRNAs) as well as its role in CC have not been clarified. Here, we reported significantly higher levels of Pttg1 and significantly lower levels of miR-494 in the resected CC tissue, compared with the adjacent normal cervical tissue from the same patient. Interestingly, Pttg1 levels inversely correlated with miR-494 levels. In vitro, Pttg1 levels determined CC cell invasiveness and were inhibited by miR-494 levels. However, miR-494 levels were not affected by Pttg1 levels. Furthermore, miR-494 inhibited Pttg1 expression in CC cells, through directly binding and inhibition on 3'-UTR of Pttg1 mRNA. Together, our data suggest that Pttg1 may increase CC cell metastasis, which is negatively regulated by miR-494. Our work thus highlights a novel molecular regulatory machinery in metastasis of CC.

Bag-1L is a stress-withstand molecule prevents the downregulation of Mcl-1 and c-Raf under control of heat shock proteins in cisplatin treated HeLa cervix cancer cells

BACKGROUND

Cisplatin, a DNA damaging agent, induces apoptosis through increasing DNA fragmentation. However, identification of intrinsic resistance molecules against Cisplatin is vital to estimate the success of therapy. Bag-1 (Bcl-2-associated anthanogene) is one anti-apoptotic protein involved in drug resistance impacting on therapeutic efficiency. Elevated levels of this protein are related with increase cell proliferation rates, motility and also cancer development. For this reason, we aimed to understand the role of Bag-1 expression in Cisplatin- induced apoptosis in HeLa cervix cancer cells. Cisplatin decreased cell viability in time- and dose-dependent manner in wt and Bag-1L+HeLa cells. Although, 10 μM Cisplatin treatment induced cell death within 24h by activating caspases in wt cells, Bag-1L stable transfection protected cells against Cisplatin treatment. To assess the potential protective role of Bag-1, we first checked the expression profile of interacting anti-apoptotic partners of Bag-1. We found that forced Bag-1L expression prevented Cisplatin-induced apoptosis through acting on Mcl-1 expression, which was reduced after Cisplatin treatment in wt HeLa cells. This mechanism was also supported by the regulation of heat shock protein (Hsp) family members, Hsp90 and Hsp40, which were involved in the regulation Bag-1 interactome including several anti-apoptotic Bcl-2 family members and c-Raf.

Anti-proliferation effects and molecular mechanisms of action of tetramethypyrazine on human SGC-7901 gastric carcinoma cells

AIM

To investigate the effects of tetramethypyrazine (TMP) on proliferation and apoptosis of the human gastric carcinoma cell line 7901 and its possible mechanism of action.

METHODS

The viability of TMP-treated 7901 cells was measured with a 3-(4, 5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and cell apoptosis was analyzed by flow cytometry. The distribution of cells in different phases of cell cycle after exposure of TMPs was analyzed with flow cytometry. To investigate the molecular mechanisms of TMP-mediated apoptosis, the expression of NF-xBp65, cyclinD1 and p16 in SGC-7901 cells was analyzed by reverse transcription- polymerase chain reaction (RT-PCR) and western blotting.

RESULTS

TMP inhibited the proliferation of human gastric carcinoma cell line 7901 in dose and time dependent manners. Cell growth was suppressed by TMP at different concentrations (0.25, 0.5, 1.0, 2.0 mg/ml), the inhibition rate is 0.46%, 4.36%, 14.8%, 76.1% (48h) and 15.5%, 18.5%, 41.2%, 89.8% (72h) respectively. When the concentration of TMPs was 2.0mg/ml, G1-phase arrest in the SGC-7901 cells was significant based on the data for cell cycle distribution. RT-PCR demonstrated that NF-xBp65 and cyclin D1 mRNA expression was significantly down-regulated in 7901 cells treated with 2.0 mg/ml TMP for 72h (p<0.05), while the p16 mRNA level was up-regulated (p<0.05). The protein expression of NF-xBp65 and cyclin D1 decreased gradually with the increase in TMP concentration, compared with control cells (p<0.05), while expression of protein p16 was up-regulated (p<0.01).

CONCLUSION

TMP exhibits significant anti-proliferative and pro-apoptotic effects on the human gastric carcinoma cell line SGC-7901. NF-xBp65, cyclinD1 and p16 may also play important roles in the regulation mechanisms.

Epigenetics and miRNA as predictive markers and targets for lung cancer chemotherapy

Lung cancer cells show inherent and acquired resistance to chemotherapy. The lack of good predictive markers/novel targets and the incomplete understanding of the mechanisms of resistance limit the success of lung cancer response to chemotherapy. In the present study, we used an isogenic pair of lung adenocarcinoma cell lines; A549 (wild-type) and A549DOX11 (doxorubicin resistant) to study the role of epigenetics and miRNA in resistance/response of non-small cell lung cancer (NSCLC) cells to doxorubicin. Our results demonstrate differential expression of epigenetic markers whereby the level of HDACs 1, 2, 3 and4, DNA methyltransferase, acetylated H2B and acetylated H3 were lower in A549DOX11 compared to A549 cells. Fourteen miRNAs were dys-regulated in A549DOX11 cells compared to A549 cells, of these 14 miRNAs, 4 (has-mir-1973, 494, 4286 and 29b-3p) have shown 2.99 - 4.44 fold increase in their expression. This was associated with reduced apoptosis and higher resistance of A549DOX11cells to doxorubicin and etoposide. Sequential treatment with the epigenetic modifiers trichostatin A or 5-aza-2'-deoxycytidine followed by doxorubicin resulted in: (i) enhanced sensitivity of both cell lines to doxorubicin especially at low concentrations, (ii) enhanced doxorubicin-induced DNA damage in both cell lines, (iii) dysregulation of some miRNAs in A549 cells. In conclusion, A549DOX11 cells resistant to DNA damaging drugs have epigenetic profile and miRNA expression different from the sensitive cells. Moreover, epigenetic modifiers may reverse the resistance of certain NSCLC cells to DNA damaging agents by enhancing induction of DNA damage. This may open the door for using epigenetic profile/miRNA expression of some cancer cells as resistance markers/targets to improve response of resistant cells to doxorubicin and for the use of combination doxorubicin/epigenetic modifiers to reduce doxorubicin toxicity.