DNMT1 expression partially dictates 5-Azacytidine sensitivity and correlates with RAS/MEK/ERK activity in gastric cancer cells.

Though DNMTs inhibitors were widely used in myelodysplastic syndrome and leukaemia, their application in solid tumours has been limited by low response rate and lack of optimal combination strategies. In gastric cancer (GC), the therapeutic implication of KRAS mutation or MEK/ERK activation for combinational use of DNMTs inhibitors with MEK/ERK inhibitors remains elusive. In this study, stable knockdown of DNMT1 expression by lentiviral transfection led to decreased sensitivity of GC cells to 5-Azacytidine. KRAS knockdown in KRAS mutant GC cells or the MEK/ERK activation by EGF stimulation in GC cells increased DNMT1 expression, while inhibition of MEK/ERK activity by Selumetinib led to decreased DNMT1 expression. 5-Azacytidine treatment, which led to dramatic decline of DNMTs protein levels and increased activity of MEK/ERK pathway, altered the activity of MEK/ERK inhibitor Selumetinib on GC cells. Both RAS-dependent gene expression signature and expression levels of multiple MEK/ERK-dependent genes were correlated with DNMT1 expression in TCGA stomach cancer samples. In conclusion, DNMT1 expression partially dictates 5-Azacytidine sensitivity and correlates with RAS/MEK/ERK activity in GC cells. Combining DNMTs inhibitor with MEK/ERK inhibitor might be a promising strategy for patients with GC.[Figure: see text].

Clinical and virological features of asymptomatic and mild symptomatic patients with SARS-CoV-2 Omicron infection at Shanghai Fangcang shelter hospital.

OBJECTIVE: The objective of this study is to evaluate and compare clinical and virological characteristics of asymptomatic and mild symptomatic patients of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron BA.2.2 variant infection and identify risk factors associated with the prolonged viral negative conversion duration. METHODS: We conducted a retrospective observational study in a Shanghai (China) Fangcang shelter hospital from April 9 to May 17, 2022. The patient-related demographic or clinical data were retrospectively recorded. Comparisons of demographic and clinical characteristics between asymptomatic and mild-symptomatic patients were performed. Cox regression was performed to identify the risk factors of prolonged viral negative conversion duration. RESULTS: A total of 551 patients confirmed with SARS-CoV-2 Omicron variant infection were enrolled in the study. Of these, 297 patients (53.9%) were asymptomatic and 254 patients (46.1%) had mild symptoms. When comparing the clinical and virological characteristics between the asymptomatic and mild symptomatic groups, several clinical parameters, including age, gender, time to viral clearance from the first positive swab, chronic comorbidities, and vaccination dose did not show statistically significant differences. In mild symptomatic patients, the median viral negative conversion duration (NCD) was 7 days (interquartile range [IQR]: 5-9), which was comparable to the median of 7 days (IQR: 5-10) in asymptomatic patients (p = .943). Multivariate Cox analysis revealed that patients age ≥ 60 years had a significantly higher hazard ratio (HR) for prolonged viral NCD (HR: 1.313; 95% confidence interval: 1.014-1.701, p = .039). CONCLUSION: Asymptomatic and symptomatic patients with non-severe SARS-CoV-2 Omicron BA.2.2 variant infection have similar clinical features and virological courses. Old age was an independent risk factor for prolonged SARS-CoV-2 conversion time.

The Incidence and Severity of Post-ERCP Pancreatitis in Patients Receiving Standard Administration of NSAIDs: a Systematic Review and Meta-analysis.

BACKGROUND: Routine rectal administration of 100 mg of diclofenac or indomethacin was demonstrated to be an effective prevention method to prevent post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis. The systematic review and meta-analysis aimed to estimate the incidence and severity of post-ERCP pancreatitis (PEP) and explore the discrepancies of PEP incidences among different subgroups. METHODS: The PubMed, Web of Science, and Ovid EMBASE databases were searched for studies published until December 2020. Only randomized controlled trials (RCTs) reported rectal administration of 100 mg or higher doses of diclofenac or indomethacin, with PEP as the primary outcomes were eligible for inclusion. The overall and severity of PEP were estimated. Subgroup analysis was performed based on geographic regions, risk level, study beginning time, type of NSAIDs, administration time, and sample size. RESULTS: There were 26 randomized controlled trials (RCTs) with 7954 patients in 31 NSAIDs arms. The pooled incidences were 7.2% for overall PEP (95% confidence interval (CI) 5.9-8.5%), 5.0% for mild PEP (95% CI, 4.0-6.0%), and 1.5% for moderate and severe PEP (0.8-2.3%). PEP rate were higher in patients receiving rectal indomethacin than that of patients receiving rectal diclofenac (7.8% (95% CI, 6.4-9.3%) vs 3.8% (95% CI, 2.2-5.3%), p = 0.009). The PEP rates of high-risk patients and average-risk patients were 8.9% (95% CI, 5.6-12.2%) and 6.4% (95% CI, 5.1-7.6%), respectively (p = 0.160). CONCLUSIONS: The incidence of PEP was higher in patients receiving 100 mg rectal indomethacin than patients receiving 100 mg diclofenac. The effect of 100 mg diclofenac versus indomethacin on preventing PEP requires further study.

DNMT1-mediated methylation of BEX1 regulates stemness and tumorigenicity in liver cancer.

BACKGROUND & AIMS: Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) both exhibit notable cancer stem cell (CSC) features. Moreover, the development of both diseases is closely associated with the presence of CSCs. We investigated the role of brain-expressed X-linked protein 1 (BEX1) in regulating the CSC properties of HB and a subtype of HCC with high CSC features (CSC-HCC). METHODS: Stemness scores were analyzed in 5 murine HCC models. A subpopulation of BEX1-positive cells and BEX1-negative cells were sorted from HCC cell lines, and subjected to transcriptome analysis. The expression and function of BEX1 was examined via western blotting, sphere formation assays, and xenograft tumor models. RESULTS: We identified BEX1 as a novel CSC marker that was required for the self-renewal of liver CSCs. Furthermore, zebularine, a potent DNMT1 inhibitor, can induce the reactivation of BEX1 by removing epigenetic inhibition. Notably, BEX1 was highly expressed in patients with HB and CSC-HCC, but not in patients with non-CSC HCC. Moreover, DNMT1-mediated methylation of the BEX1 promoter resulted in differential BEX1 expression patterns in patients with HB, CSC-HCC, and non-CSC-HCC. Mechanistically, BEX1 interacted with RUNX3 to block its inhibition of ß-catenin transcription, which led to the activation of Wnt/ß-catenin signaling, and stemness maintenance in both HB and CSC-HCC. In contrast, downregulated BEX1 expression released RUNX3 and inhibited the activation of Wnt/ß-catenin signaling in non-CSC-HCC. CONCLUSION: BEX1, under the regulation of DNMT1, is necessary for the self-renewal and maintenance of liver CSCs through activation of Wnt/ß-catenin signaling, rendering BEX1 a potentially valuable therapeutic target in both HB and CSC-HCC. LAY SUMMARY: Cancer stem cells (CSCs) contribute to a high rate of cancer recurrence, as well as resistance to conventional therapies. However, the regulatory mechanisms underlying their self-renewal remains elusive. Herein, we have reported that BEX1 plays a key role in regulating CSC properties in different types of liver cancer. Targeting BEX1-mediated Wnt/ß-catenin signaling may help to address the high rate of recurrence, and heterogeneity of liver cancer.

Oncogenic driver genes and tumor microenvironment determine the type of liver cancer.

Primary liver cancer (PLC) may be mainly classified as the following four types: hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), hepatoblastoma (HB), and combined hepatocellular carcinoma and intrahepatic cholangiocarcinoma (cHCC-ICC). The majority of PLC develops in the background of tumor microenvironment, such as inflammatory microenvironments caused by viral hepatitis, alcoholic or nonalcoholic steatohepatitis, carbon tetrachloride (CCl4), 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), and necroptosis-associated hepatic cytokine microenvironment caused by necroptosis of hepatocytes. However, the impact of different types of microenvironments on the phenotypes of PLC generated by distinct oncogenes is still unclear. In addition, the cell origin of different liver cancers have not been clarified, as far as we know. Recent researches show that mature hepatocytes retain phenotypic plasticity to differentiate into cholangiocytes. More importantly, our results initially demonstrated that HCC, ICC, and cHCC-ICC could originate from mature hepatocytes rather than liver progenitor cells (LPCs), hepatic stellate cells (HSCs) and cholangiocytes in AKT-driven, AKT/NICD-driven and AKT/CAT-driven mouse PLC models respectively by using hydrodynamic transfection methodology. Therefore, liver tumors originated from mature hepatocytes embody a wide spectrum of phenotypes from HCC to CC, possibly including cHCC-ICC and HB. However, the underlying mechanism determining the cancer phenotype of liver tumors has yet to be delineated. In this review, we will provide a summary of the possible mechanisms for directing the cancer phenotype of liver tumors (i.e., ICC, HCC, and cHCC-ICC) in terms of oncogenic driver genes and tumor microenvironment. Moreover, this study initially revealed the cell origin of different types of liver cancer.

Direct Infusion ICP-qMS of Lined-up Single-Cell Using an Oil-Free Passive Microfluidic System.

When coupled online with mass spectrometry (MS), widely applied water-in-oil droplet-based microfluidics for single cell analysis met problems. For example, the oil phase rumpled the stability, efficiency, and accuracy of MS, the conventional interface between MS and the microfluidic chip suffered the low sample introduction efficiency, and the transportation rates sometimes unmatched the readout dwell times for transient signal acquisition. Considering cells are already "droplets" with hydrophilic surface and elastic hydrophobic membrane, we developed an oil-free passive microfluidic system (OFPMS) that consists of alternating straight-curved-straight microchannels and a direct infusion (dI) micronebulizer for inductively coupled plasma quadrupole-based mass spectrometry (ICP-qMS) of lined-up single-cell. OFPMS guarantees exact single cell isolation one by one just using a thermo-decomposable NH4HCO3 buffer, eliminating the use of any oil and incompatible polymer carriers. It is more flexible and facile to adapt to the dwell time of ICP-qMS owing to the adjustable throughput of 400 to 25000 cells/min and the controllable interval time of at least 20 ms between the lined-up adjacent single cells. Quantitative single-cell transportation and high detection efficiency of more than 70% was realized using OFPMS-dI-ICP-qMS exemplified here. Thus, cell-to-cell heterogeneity can be simply uncovered via the determination of metals in the individual cells.

Forkhead box K2 promotes human colorectal cancer metastasis by upregulating ZEB1 and EGFR.

Background: Metastasis is the major reason for high recurrence rates and poor survival among patients with colorectal cancer (CRC). However, the underlying molecular mechanism of CRC metastasis is unclear. This study aimed to investigate the role of forkhead box K2 (FOXK2), one of the most markedly increased FOX genes in CRC, and the mechanism by which it is deregulated in CRC metastasis. Methods: FOXK2 levels were analyzed in two independent human CRC cohorts (cohort I, n = 363; cohort II, n = 390). In vitro Transwell assays and in vivo lung and liver metastasis models were used to examine CRC cell migration, invasion and metastasis. Chromatin immunoprecipitation and luciferase reporter assays were used to measure the binding of transcription factors to the promoters of FOXK2, zinc finger E-box binding homeobox 1 (ZEB1) and epidermal growth factor receptor (EGFR). Cetuximab was utilized to treat FOXK2-mediated metastatic CRC. Results: FOXK2 was significantly upregulated in human CRC tissues, was correlated with more aggressive features and indicated a poor prognosis. FOXK2 overexpression promoted CRC migration, invasion and metastasis, while FOXK2 downregulation had the opposite effects. ZEB1 and EGFR were determined to be direct transcriptional targets of FOXK2 and were essential for FOXK2-mediated CRC metastasis. Moreover, activation of EGFR signaling by EGF enhanced FOXK2 expression via the extracellular regulated protein kinase (ERK) and nuclear factor (NF)-κB pathways. The EGFR monoclonal antibody cetuximab significantly inhibited FOXK2-promoted CRC metastasis. In clinical CRC tissues, FOXK2 expression was positively correlated with the expression of p65, ZEB1 and EGFR. CRC patients who coexpressed p65/FOXK2, FOXK2/ZEB1 and FOXK2/EGFR had poorer prognosis. Conclusions: FOXK2 serves as a prognostic biomarker in CRC. Cetuximab can block the EGF-NF-κB-FOXK2-EGFR feedback loop and suppress CRC metastasis.

Towards a high peak capacity of 130 using nanoflow hydrophilic interaction liquid chromatography.

Hydrophilic interaction liquid chromatography, HILIC, is a relatively new HPLC mode. Compared with other HPLC modes, HILIC is a high resolution chromatographic mode with high peak capacity for separations of complex mixtures. Although the separation mechanism is still not completely clear, HILIC has been widely used for analysis of hydrophilic compounds which are difficult for reversed phase chromatography to retain and separate. In this study, we fabricated and investigated nanoHILIC columns in terms of separation efficiency, van Deemter curves and more importantly, we focused on long packed capillary columns, and studied their extreme resolution for protein digests. Using meter long nanoHILIC columns packed with 5 µm particles, we realized a high peak capacity of 130. Based on nanoLC-MS, we compared the resolution and protein identification capabilities of nanoHILIC and nanoRPLC. The results indicate both nanoHILIC and nanoRPLC can provide high resolution for protein sequencing but neither mode is significantly better than the other. Among the 99 digest peptides identified, 17 were uniquely identified by nanoHILIC-MS and 20 were uniquely identified by nanoRPLC-MS and 62 were identified by both methods. Although at this moment in time, nanoRPLC is the most popular microseparation tool in proteomics, the excellent complementarity of nanoHILIC and nanoRPLC suggests their combined use in achieving deep-coverage in MS-based proteomics.

Forkhead box C1 promotes colorectal cancer metastasis through transactivating ITGA7 and FGFR4 expression.

Metastatic colorectal cancer (CRC) is one of the most common causes of cancer death worldwide; however, the molecular mechanism underlying CRC metastasis remains unknown. Using an integrated approach, we identified forkhead box C1 (FOXC1) as a novel regulator of CRC metastasis. Elevated expression of FOXC1 is significantly correlated with metastasis, recurrence and reduced survival. FOXC1 overexpression promotes CRC invasion and lung metastasis, whereas FOXC1 knockdown has the opposite effect. In addition, FOXC1 directly binds its target genes integrin α7 (ITGA7) and fibroblast growth factor receptor 4 (FGFR4) and activates their expression. Genetic epistasis analysis confirmed that ITGA7 and FGFR4 act downstream of FOXC1. Furthermore, pharmaceutical inhibition of FGFR4 can reverse CRC metastasis mediated by FOXC1 overexpression. These results suggest that FOXC1 is a prognostic biomarker in CRC patients and targeting the FGFR4 signaling pathway may provide a promising strategy for the treatment of FOXC1-driven CRC metastasis.

Berberine inhibits EGFR signaling and enhances the antitumor effects of EGFR inhibitors in gastric cancer.

Cetuximab plus chemotherapy for advanced gastric cancer (GC) shows an active result in phase 2 trials. Unfortunately, Combination of cetuximab does not provide enough benefit to chemotherapy alone in phase 3 trials. Studies have demonstrated that berberine can suppress the activation of EGFR in tumors. In this study, we evaluated whether berberine could enhance the effects of EGFR-TKIs in GC cell lines and xenograft models. Our data suggest that berberine could effectively enhance the activity of erlotinib and cetuximab in vitro and in vivo. Berberine was found to inhibit growth in GC cell lines and to induce apoptosis. These effects were linked to inhibition of EGFR signaling activation, including the phosphorylation of STAT3. The expressions of Bcl-xL and Cyclind1 proteins were decreased, whereas the levels of cleavage of poly-ADP ribose polymerase (PARP) were considerably increased in the cell lines in response to berberine treatment. These results suggest a potential role for berberine in the treatment of GC, particularly in combination with EGFR-TKIs therapy. Berberine may be a competent therapeutic agent in GC where it can enhance the effects of EGFR inhibitors.

Interleukin-8 Induces Expression of FOXC1 to Promote Transactivation of CXCR1 and CCL2 in Hepatocellular Carcinoma Cell Lines and Formation of Metastases in Mice.

BACKGROUND & AIMS: Inflammation regulated by interleukin (IL) 8 promotes metastasis of hepatocellular carcinoma (HCC). The transcription factor forkhead box C1 (FOXC1) promotes metastasis by activating the epithelial to mesenchymal transition; its levels in liver tumors have been associated with shorter survival times of patients. We investigated whether FOXC1 activates inflammation signaling pathways in HCC cell lines. METHODS: We performed studies in the human HCC cell lines Huh-7 and SMMC7721, as well as the metastatic cell lines MHCC97H and HCCLM3. Cell lines were incubated with IL8 and transcription of reporter genes was measured; cells were also incubated with kinase inhibitors. Levels of FOXC1 or IL8 were knocked down with small interfering messenger RNAs in Huh7 cells; cells were analyzed in vitro in migration and invasion assays. To study metastasis, HCC cells were injected into flanks of BALB/C nude mice; 4 weeks later, the subcutaneous tumor fragments were collected and implanted into livers of the nude mice, and number and size tumors formed were measured. Chromatin immunoprecipitation assays were used to measure binding of transcription factors promoter regions of genes. We measured levels of FOXC1, IL8, CXCR1, and CCL2 in 2 groups of human HCC tissues collected from the Xijing or Tongji Hospitals in China (n = 690 and n = 312 samples, respectively) using immunohistochemistry. RESULTS: Incubation of HCC cells with IL8 led to increased expression of FOXC1, via activation of phosphoinositide 3-kinase signaling to AKT and hypoxia-inducible factor 1α. Knockdown of FOXC1 in HCC cells that overexpressed IL8 reduced the numbers of metastases formed in mice, compared with cells without FOXC1 knockdown. Transgenic overexpression of FOXC1 in HCC cells with IL8 knockdown increased the numbers of metastases formed in mice compared with cells without FOXC1 overexpression. CXCR1 and CCL2 were direct transcriptional targets of FOXC1. Knockdown of the combination of CXCR1 and CCL2 reduced the invasive activities of HCC cells that overexpress FOXC1 and formation of lung metastases in mice, and transgenic overexpression of CXCR1 increased cell's invasive and metastatic abilities after knockdown of FOXC1. Liver metastases grown from cells that overexpressed FOXC1 were infiltrated by tumor-associated macrophages, and CCL2 knockdown decreased tumor-associated macrophage infiltration; depletion of macrophages from mice significantly reduced growth of metastases by cells that overexpressed FOXC1. In human HCC tissues, level of FOXC1 correlated with levels of IL8 and CXCR1 and CCL2 and infiltration of tumors by macrophage. In multivariate analysis, detection of FOXC1 and CCL2 were independent predictors for postoperative recurrence of HCC and overall survival. CONCLUSIONS: In HCC cell lines, IL8 activates expression of FOXC1 via the phosphoinositide 3-kinase signaling to AKT and hypoxia-inducible factor 1α. FOXC1 expression leads to transactivation of CXCR1 and CCL2, promoting inflammation and the invasive and metastatic abilities of HCC cells.

Sox12, a direct target of FoxQ1, promotes hepatocellular carcinoma metastasis through up-regulating Twist1 and FGFBP1.

UNLABELLED: Metastasis is the main reason for high recurrence and poor survival of hepatocellular carcinoma (HCC) after curative resection. However, the molecular mechanism underlying HCC metastasis remains unclear. Here, we report on a novel function of SRY (sex determining region Y)-box 12 (Sox12), a member of the SYR-related high mobility group box family proteins, in promoting HCC metastasis. Overexpression of Sox12 was significantly correlated with loss of tumor encapsulation, microvascular invasion, and a higher tumor-nodule-metastasis (TNM) stage and indicated poor prognosis in human HCC patients. Sox12 expression was an independent and significant risk factor for recurrence and reduced survival after curative resection. Overexpression of Sox12 induced epithelial-mesenchymal transition by transactivating Twist1 expression. Down-regulation of Twist1 decreased Sox12-enhanced HCC migration, invasion, and metastasis, whereas up-regulation of Twist1 rescued the decreased migration, invasion, and metastasis induced by Sox12 knockdown. Additionally, serial deletion, site-directed mutagenesis, and chromatin immunoprecipitation assays showed that fibroblast growth factor binding protein 1 (FGFBP1) was a direct transcriptional target of Sox12. Knockdown of FGFBP1 decreased Sox12-mediated HCC invasion and metastasis, whereas overexpression of FGFBP1 rescued the decreased invasion and metastasis induced by Sox12 knockdown. Furthermore, forkhead box Q1 (FoxQ1) directly bound to the Sox12 promoter and transactivated its expression, which contributed to Sox12 overexpression in human HCC. Knockdown of Sox12 dramatically decreased FoxQ1-mediated HCC metastasis. In two independent cohorts of human HCC tissues, Sox12 expression was positively correlated with Twist1, FGFBP1, and FoxQ1 expression, and patients with positive coexpression of Sox12/Twist1, Sox12/FGFBP1, or FoxQ1/Sox12 were associated with poorer prognosis. CONCLUSION: Up-regulated Sox12 induced by FoxQ1 promotes HCC invasion and metastasis by transactivating Twist1 and FGFBP1 expression. Thus, our study implicates Sox12 as a potential prognostic biomarker and a novel therapeutic target for HCC.

Activation of PAX3-MET pathways due to miR-206 loss promotes gastric cancer metastasis.

MicroRNAs (miRNAs) are thought to have an important role in tumor metastasis by regulating diverse cellular pathways. Here, we describe the function and regulation network of miR-206 in gastric cancer (GC) metastasis. MiR-206 expression was downregulated in GC cells especially in high metastatic potential cells and was also significantly decreased in metastatic lesions compared with their corresponding primary tumor samples. Both gain- and loss-of-function studies confirmed that miR-206 significantly suppressed GC cell invasion and metastasis both in vitro and in vivo. Mechanistically, paired box gene 3 (PAX3) was identified as a functional target of miR-206 in GC cells. MiR-206 inhibited GC metastasis by negatively regulating expression of PAX3. In addition, PAX3 expression was markedly higher in GC tissues than in adjacent non-cancerous tissues. GC patients with positive PAX3 expression had shorter overall survival times. Transwell assays and in vivo metastasis assays demonstrated that overexpression of PAX3 significantly promoted the invasiveness and pulmonary metastasis of GC cells. On the other hand, downregulation of PAX3 markedly reduced cell metastatic potential. Mechanistic investigations indicated that prometastasis function of PAX3 was mediated by upregulating downstream target MET. Moreover, we found that levels of PAX3 and MET were positively correlated in matched human GC specimens, and their coexpression was associated with poor prognoses. In conclusion, our results reveal that miR-206-PAX3-MET signaling is critical to GC metastasis. Targeting the pathway described here may open new therapeutic prospects to restrict the metastatic potential of GC.

Decreased expression of FOXJ1 is a potential prognostic predictor for progression and poor survival of gastric cancer.

BACKGROUND: FOXJ1 is a member of the forkhead transcription factor family, which has been mostly studied for its role in the development of ciliated epithelium and immunology. However, the role of FOXJ1 in tumorigenesis remains largely unknown or even conflicting. We thus investigated FOXJ1 expression in gastric cancer and analyzed its correlations with tumor progression and prognosis. METHODS: The expression of FOXJ1 was detected by immunohistochemistry in 105 gastric cancer samples and adjacent noncancerous tissues. Staining evaluation was conducted to assess clinicopathological parameters and the survival rate. In addition, the relation between FOXJ1 and metastasis was investigated in another 40 pairs of primary lesions and corresponding lymph node metastases. Furthermore, cell proliferation, migration, and invasion were confirmed in vitro. RESULTS: Decreased FOXJ1 expression was significantly correlated with clinic stage, lymph node metastasis, and distant metastasis, and lower FOXJ1 expression independently predicted shorter survival time in gastric carcinoma. Moreover, the positive incidence of FOXJ1 decreased significantly in metastatic lymph nodes compared with that in the primary lesions. Consistently, FOXJ1 overexpression significantly weakened cell proliferation, motility, migration, and invasion, while FOXJ1 knockdown induced the opposite effects. CONCLUSIONS: Decreased expression of FOXJ1 is an independent prognostic predictor for gastric cancer and is critical to disease progression. FOXJ1 may be an attractive therapeutic target for the treatment of gastric cancer.

Genomic analysis of drug resistant gastric cancer cell lines by combining mRNA and microRNA expression profiling.

Understanding the mechanism underlying multidrug resistance and identifying effective targets that can overcome it is of critical importance. In this study, mRNA and miRNA expression profiling of the drug resistant sublines, SGC7901/VCR and SGC7901/ADR, and their parental gastric cancer cell line SGC7901 were performed. A significant number of genes and a limited subset of miRNAs were commonly dysregulated, which were further validated using qRT-PCR. GO and KEGG pathway analyses of the commonly dysregulated genes indicated that the MAPK signalling pathway may be involved in multidrug resistance, which was further validated using immunoblotting and MTT assay. Finally a primary multidrug resistance network in gastric cancer, consisting of the commonly dysregulated genes and miRNAs, was established and functional miRNA-mRNA pairs were identified. The commonly dysregulated genes and miRNAs identified in this study may represent good therapeutic targets and further study of these targets may increase our understanding of the mechanisms underlying multidrug resistance.

Forkhead box Q1 promotes hepatocellular carcinoma metastasis by transactivating ZEB2 and VersicanV1 expression.

UNLABELLED: Forkhead box Q1 (FoxQ1) is a master regulator of tumor metastasis. However, the molecular mechanism of FoxQ1 in regulating hepatocellular carcinoma (HCC) metastasis remains unknown. Here we report a novel function for FoxQ1 in modifying the tumor microenvironment to promote HCC metastasis. FoxQ1 expression was an independent and significant risk factor for the recurrence and survival in two independent cohorts totaling 1,002 HCC patients. FoxQ1 induced epithelial-mesenchymal transition (EMT) through the transactivation of ZEB2 expression by directly binding to the ZEB2 promoter. Knockdown of ZEB2 decreased FoxQ1-enhanced HCC metastasis, whereas up-regulation of ZEB2 rescued the decreased metastasis induced by FoxQ1 knocking down. Additionally, serial deletion, site-directed mutagenesis, and a chromatin immunoprecipitation assays showed that VersicanV1, which promoted HCC metastasis and macrophage attraction, was a direct transcriptional target of FoxQ1. FoxQ1-induced VersicanV1 expression promoted the secretion of chemokine (C-C motif) ligand 2 (CCL2) from HCC cells. Chemotaxis assay showed that the culture media from FoxQ1-overexpressing HCC cells increased the migratory activity of the macrophages. Inhibition of VersicanV1 and CCL2 expression significantly inhibited FoxQ1-mediated macrophage migration. In animal studies, the up-regulation of FoxQ1 in HCC cells promoted HCC metastasis and intratumoral tumor associated macrophage (TAM) infiltration, whereas knockdown of VersicanV1 reduced FoxQ1-mediated HCC metastasis and intratumoral TAM infiltration. Depletion of macrophages using clodronate liposomes dramatically decreased FoxQ1-enhanced HCC metastasis. In human HCC tissues, FoxQ1 expression was positively correlated with ZEB2 and VersicanV1 expression and intratumoral TAM infiltration. Patients with positive coexpression of FoxQ1 and ZEB2, FoxQ1, and VersicanV1, or FoxQ1 and intratumoral TAMs were associated with poorer prognosis. CONCLUSION: FoxQ1 promotes HCC metastasis by transactivating ZEB2 and VersicanV1 expression, resulting in the induction of EMT and the recruitment of macrophage infiltration.

miR-206 inhibits gastric cancer proliferation in part by repressing cyclinD2.

In this study, we detected miR-206 expression in gastric cancer (GC) and further investigated its effects on GC cell growth in vitro and in vivo. miR-206 expression was found to be significantly decreased in 30 GC samples and GC cell lines by real time-PCR. Restoration of miR-206 reduced cell growth and colony forming ability in GC cells with G0/G1 cell cycle arrest. Further studies demonstrated that miR-206 could suppress GC cells proliferation at least partially through targeting the cyclinD2 (CCND2). Therefore, we provided evidence that miR-206 was a potential tumor suppressor and may be used as a therapeutic target for gastric cancer.

The TNF-α/ROS/HIF-1-induced upregulation of FoxMI expression promotes HCC proliferation and resistance to apoptosis.

The proliferation-specific transcription factor Forkhead box M1 (FoxM1) acts as a master regulator of cancer cell growth and survival and plays an important role in the development of hepatocellular carcinoma. However, the molecular mechanisms that regulate FoxM1 expression remain largely unknown. In the current study, we demonstrated that tumor necrosis factor (TNF)-αα induced FoxM1 expression and transactivated its promoter activity in hepatoma cells. Serial 5" deletion and site-directed mutagenesis revealed that the induction of FoxM1 expression by TNF-α was dependent upon the hypoxia-inducible factor 1 (HIF1)-1 and HIF1-3/4 binding sites within the FoxM1 promoter. Furthermore, at the transcriptional level, the stabilization of HIF-1α via reactive oxygen species generation led to the binding of HIF-1α to the FoxM1 promoter and resulted in increased FoxM1 expression. The inhibition of both HIF-1α expression and reactive oxygen species generation significantly decreased TNF-α-induced FoxM1 overexpression. Consequently, the upregulation of FoxM1 promoted the proliferation of hepatoma cells and enhanced their resistance to TNF-α-induced apoptosis. Consistently, there was a positive correlation between HIF-1α and FoxM1 expression in 406 human hepatocellular carcinoma tissues, and the combination of these two parameters was a powerful predictor of poor prognosis in hepatocellular carcinoma patients after curative resection. Here, we report a new molecular mechanism by which FoxM1 expression is regulated by the TNF-α/reactive oxygen species/HIF-1 pathway, and this mechanism results in the proliferation of hepatoma cells and their resistance to apoptosis.