Association of ESR1 and ESR2 Polymorphisms with Osteoporosis: A Meta-Analysis from 36 Studies.

BACKGROUND: Recently, the roles of ESR1 and ESR2 polymorphisms in osteoporosis have been extensively reported, with conflicting findings. Therefore, we performed this present study to evaluate the potential associations between ESR1 and ESR2 polymorphisms and osteoporosis risk. METHODOLOGY: All included literatures published up to April 2021 were identified by searching Pubmed, Embase, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated the associations using a fixed or random effects model. RESULTS: 36 observational studies involving five gene polymorphisms (ESR1 PvuII, ESR1 XbaI, ESR1 G2014A, ESR2 AluI and ESR2 RsaI) covering 12507 cases and 18487 controls were included. The results of our meta-analysis demonstrated the variant A allele of ESR2 RsaI polymorphism might play a remarkable protective role in developing osteoporosis under all genetic models. However, no associations were observed between ESR1 PvuII, ESR1 XbaI, ESR1 G2014A and ESR2 AluI polymorphisms with the risk of osteoporosis under all genetic models. CONCLUSIONS: Our meta-analysis suggests that genetic polymorphism in ESR2 RsaI may lead to decreased risk for osteoporosis. Further larger studies are needed to confirm this conclusion.

Association between IL-1B gene polymorphisms and Helicobacter pylori infection: A meta-analysis.

BACKGROUND: To clarify the impact of IL-1B gene polymorphisms (IL-1B-511C/T, IL-1B-31C/T, IL-1B+3954C/T) in Helicobacter pylori (H. pylori) infection by mean of a meta-analysis. METHODS: The relevant studies were retrieved from PubMed, Web of Science, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases until September 9, 2018. Odds ratio (OR) and its 95% confidence intervals (CIs) were used to assess the associations. Statistical analyses of this meta-analysis were conducted by using STATA 12 software. RESULTS: Totally, 45 articles including 9606 cases and 5654 controls were enrolled in this meta-analysis. Our results indicated that IL-1B-511C/T polymorphism was significantly related to an increased the risk of H. pylori infection under recessive model (OR = 1.13, 95% CI: 1.00-1.27, P = 0.048). However, no significant associations were obtained between H. pylori infection and IL-1B-31C/T as well as IL-1B+3954C/T polymorphisms under all models. In addition, subgroup analyses were also performed by country, study design, and detection methods of H. pylori. CONCLUSIONS: This meta-analysis suggested that IL-1B-511C/T polymorphism was related to the risk of H. pylori infection. Further larger studies with high quality are needed to conform these findings.

Expression and clinical significance of retinoid X receptor α in esophageal carcinoma.

PURPOSE: Esophageal carcinoma (EC) is one of the most aggressive type cancers and dysregulation of retinoid X receptor α (RXRα) involves various tumors. However, the relationship of RXRα with the clinicopathological factors of EC, particularly prognostic characteristics, remains unclear. This present study was to evaluate the effect of RXRα expression in the development of EC. METHODS: The mRNA and protein expression level of RXRα in EC and normal esophageal tissues using reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively. The subcellular localization was detected by immunohistochemistry (IHC) analysis. The clinicopathological parameters were included age, sex, tumor size, differentiation, TNM stages and lymph node metastasis. Kaplan-Meier method and Cox's regression analyses were performed to evaluate the prognosis of 60 patients with EC. RESULTS: RXRα was elevated in EC tissues comparing with normal esophageal tissues at both mRNA and protein levels. The overexpression level of RXRα was closely associated to the tumor differentiation, TNM stage and lymph node metastasis of patients with EC. In addition, EC patients with RXRα high expression had significantly lower disease-free survival (DFS) and overall survival (OS). Multivariate analysis showed RXRα expression as an independent predictor for the DFS and OS rate of patients with EC. CONCLUSIONS: Our results showed that overexpression of RXRα was correlated with unfavorable prognosis, suggesting that RXRα may serve as a potential targeted therapeutic marker in the treatment of EC.

Efficient isolation and proteomic analysis of cell plasma membrane proteins in gastric cancer reveal a novel differentiation and progression related cell surface marker, R-cadherin.

Cell plasma membrane proteins, playing a crucial role in cell malignant transformation and development, were the main targets of tumor detection and therapy. In this study, CyDye/biotin double-labeling proteomic approach was adopted to profile the membrane proteome of gastric cancer cell line BGC-823 and paired immortalized gastric epithelial cell GES-1. Real-time PCR, Western blotting, and immunohistochemical staining were used to validate the differential expression of a novel identified cell surface marker R-cadherin in gastric cancer cells and tissues. Clinicopathological study and survival analysis were performed to estimate its roles in tumor progression and outcome prediction. Real-time PCR and Western blotting showed that the expression level of R-cadherin in gastric cancer were significantly lower than non-cancerous epithelial cell and tissues. Clinicopathological study indicated that R-cadherin was dominantly expressed on cell surface of normal gastric epithelium, and its expression deletion in gastric cancer tissues was associated with tumor site, differentiation, lymph node metastasis, and pTNM (chi-square test, P < 0.05). Those patients with R-cadherin positive expression displayed better overall survivals than negative expression group (log-rank test, P = 0.000). Cox multivariate survival analysis revealed lacking the expression of R-cadherin was a main independent predictor for poor clinical outcome in gastric cancer (RR = 5.680, 95 % CI 2.250-14.341, P < 0.01). We have established a fundamental membrane proteome database for gastric cancer and identified R-cadherin as a tumor differentiation and progression-related cell surface marker of gastric cancer. Lacking the expression of R-cadherin indicates poor prognosis in patients with gastric cancer.

Retinoid X receptor α enhances human cholangiocarcinoma growth through simultaneous activation of Wnt/ß-catenin and nuclear factor-κB pathways.

Retinoid X receptor α (RXRα) plays important roles in the malignancy of several cancers such as human prostate tumor, breast cancer, and thyroid tumor. However, its exact functions and molecular mechanisms in cholangiocarcinoma (CCA), a chemoresistant carcinoma with poor prognosis, remain unclear. In this study we found that RXRα was frequently overexpressed in human CCA tissues and CCA cell lines. Downregulation of RXRα led to decreased expression of mitosis-promoting factors including cyclin D1and cyclin E, and the proliferating cell nuclear antigen, as well as increased expression of cell cycle inhibitor p21, resulting in inhibition of CCA cell proliferation. Furthermore, RXRα knockdown attenuated the expression of cyclin D1 through suppression of Wnt/ß-catenin signaling. Retinoid X receptor α upregulated proliferating cell nuclear antigen expression through nuclear factor-κB (NF-κB) pathways, paralleled with downregulation of p21. Thus, the Wnt/ß-catenin and NF-κB pathways account for the inhibition of CCA cell growth induced by RXRα downregulation. Retinoid X receptor α plays an important role in proliferation of CCA through simultaneous activation of Wnt/ß-catenin and NF-κB pathways, indicating that RXRα might serve as a potential molecular target for CCA treatment.

Unveiling the role of RARs in stomach adenocarcinoma: clinical implications and prognostic biomarkers.

Background: Retinoic acid receptors (RARs) family are known to play a significant role in the occurrence and development of tumors. However, the relationship between RARs and stomach adenocarcinoma (STAD) has not yet been clearly identified. The aim of this study is to evaluate the expression profile and clinical value of the RARs family in STAD. Methods: The expression level, clinical characteristics, prognostic value, immunity-related evaluations, genetic alteration and methylation site of RARs in STAD were explored using a series of online databases including gene expression profiling interactive analysis (GEPIA), tumor immune estimation resource (TIMER), University of Alabama at Birmingham cancer data (UALCAN), Human Protein Atlas (HPA), Kaplan-Meier plotter, gene set cancer analysis (GSCA), cBioPortal, MethSurv, GeneMANIA, LinkedOmics, Metascape, Search tool for the retrieval of interacting genes (STRING), tumor immune single-cell hub (TISCH) and cancer cell line encyclopedia (CCLE). Results: We discovered dramatically increased expression of RARA and decreased expression of RARB in STAD tissues, and many clinical variables were closely related to RARs. Notably, higher expressions of RARA and RARB as well as lower expression of RARG correlated with worse overall survival (OS) for STAD patients. The clinical value of prognostic model indicated that RARs were identified to be potential prognostic biomarkers for STAD patients. Moreover, RARB was closely related to immune cell infiltration, which had effect on the role of RARB in STAD prognosis. And the genetic alteration of RARB was significantly associated with the longer disease-free survival (DFS) of STAD patients. Additionally, some CpG sites of the RARs family were related with the prognosis of STAD patients. Functional enrichment analyses indicated that several pathways in STAD might be pivotal pathways regulated by RARs. At the single-cell level, there was some extent of infiltration of tumor microenvironment-related cells in the RARs expression in STAD. Conclusions: Our results evaluated the expression profile and clinical values of RARs in patients with STAD, which provided a basis for future in-depth exploration of the specific mechanisms of each member of RARs in STAD.

Comprehensive analysis of the clinical and biological significances for chemokine CXCL3 in cholangiocarcinoma.

Cholangiocarcinoma (CHOL) is a race malignant cancer arising from bile duct epithelial cells in clinical practice. C-X-C motif chemokine ligand 3 (CXCL3) is a member of chemokines family, which participates in the pathogenesis of various tumors. However, the association between CXCL3 and CHOL is unclear. This present study was to assess the role of CXCL3 expression in the progress of CHOL. TIMER, GEPIA, UALCAN, GSCA, LinkedOmics, Metascape and STRING databases were performed to evaluate the clinical and biological significances for CXCL3 with CHOL patients including expression, clinicopathological factors, immune cell infiltration, GO enrichment and KEGG pathway analyses, as well as PPI network analysis. The immunohistochemistry analysis of tissue microarray was conducted to detect the protein expression level, subcellular localization, clinicopathological factors and prognosis of CXCL3 in CHOL. The mRNA and protein expression levels of CXCL3 were markedly increased in CHOL tissues. The overexpression of CXCL3 was strongly associated with maximum tumor diameter of patients with CHOL. Additionally, there were negative correlations between the expression of CXCL3 and monocyte as well as Th17. Low infiltration of neutrophil indicated significantly shorter cumulative survival in CHOL patients. And CXCL3 was significantly associated with arm-level deletion of CD8+ T cell. Furthermore, functional network analysis suggested that CXCL3 and its associated genes were mainly enriched for chemotaxis, secretory granule membrane, cytokine activity and IL-17 signaling pathway. CXCL3 might potentially participate in the carcinogenesis of CHOL, which provided a direction for future research on the mechanism of CXCL3 in CHOL.

Association of genetic polymorphisms with COVID-19 infection and outcomes: An updated meta-analysis based on 62 studies.

Background: The relationship between genetic polymorphisms and coronavirus disease 2019 (COVID-19) remains to be inconsistent. This meta-analysis aimed to provide an updated evaluation of the role of genetic polymorphisms in the infection, severity and mortality of COVID-19 based on all available published studies. Methods: A systematic search was performed using six databases: PubMed, Embase, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI) and Wanfang. Summary odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were used to calculate the genotypic comparison. All statistical analyses were conducted in Stata 12.0. Results: A total of 62 studies with 19600 cases and 28899 controls was included in this meta-analysis. For COVID-19 infection, ACE Ins/Del polymorphism might be related with significantly decreased risk of COVID-19 infection under dominant, homozygote and allelic models. Meanwhile, the IFITM3 rs12252 and TMPRSS2 rs12329760 polymorphisms were significantly associated with the increased risk of COVID-19 infection under one or more models. Regarding COVID-19 severity, ACE2 rs2074192, ACE2 rs2106809, IFITM3 rs12252 and VDR rs1544410 polymorphisms might be related with significantly increased risk of COVID-19 severity in one or more models. Moreover, the analysis of TMPRSS2 rs2070788 indicated that a variant A allele decreased the risk of COVID-19 severity in recessive model. For COVID-19 mortality, the variant C allele of IFITM3 rs12252 polymorphism might be related with significantly increased risk of COVID-19 mortality under all genetic models. Conclusions: This meta-analysis indicated that he infection, severity or mortality of COVID-19 were related to the above genetic polymorphisms, which might provide an important theoretical basis for understanding the clinical feature of COVID-19 disease.

Atypical and bilateral pigmented villonodular synovitis of wrist in an adolescent patient: case report and literature review.

BACKGROUND: Pigmented villonodular synovitis (PVNS) is a rare benign proliferative disorder of the synovium. It rarely occurs in adolescents, particularly in immature patients with bilateral manifestation. CASE PRESENTATION: We present a case of atypical and bilateral PVNS of wrist in a 14-year-old boy. Initially, the patient presented with left wrist pain and swelling without the history of trauma. Physical examination revealed an obvious lesion in the dorsal part of left wrist. Radiographs, computed tomography (CT) and magnetic resonance imaging (MRI) showed multiple abnormal signal shadows and arthroedema in the left wrist. Arthroscopy operation was performed, and histologic examination suggested the diagnosis of PVNS. Only 10 months later, the patient presented with the similar symptoms and signs in the right wrist. But MIR and histologic examination were atypical. In this article, we also review and summarize 26 studies on 30 adolescent patients with PVNS. CONCLUSIONS: This study provides an example of atypical and bilateral PVNS in adolescents.

The Clinicopathologic and Prognostic Value of Hypoxia-Inducible Factor-2α in Cancer Patients: A Systematic Review and Meta-Analysis.

Hypoxia-inducible factor-2α (HIF2α) plays an important role in the development of tumors. However, the clinicopathologic and prognostic significance of HIF2α in cancer patients remains controversial. Therefore, we performed a meta-analysis to investigate the relationship between the HIF2α status and clinical outcome in human cancer. Studies were screened online using electronic databases. The pooled risk ratios or hazard ratios (HR) with their 95% confidence intervals (CI) were calculated from available publications. Subgroup analysis, sensitivity analysis, heterogeneity, and publication bias were also conducted. A total of 854 studies with 4,345 patients were obtained in this meta-analysis. The results indicated that the increased expression of HIF2α could predict unfavorable overall survival of cancer patients on both univariate analysis (HR, 1.64; 95% CI, 1.41-1.92, P < 0.001) and multivariate analysis (HR, 2.21; 95% CI, 1.70-2.87, P < 0.001). Moreover, HIF2α overexpression was associated closely with tumor differentiation, tumor-node-metastasis stage, and lymph metastasis. In addition, there was no obvious evidence for significant publication bias in this meta-analysis. Our study indicated that HIF2α might be an indicator of poor prognosis and clinicopathologic features of tumors and could serve as a novel biomarker in human cancer.

Clinicopathological and prognostic value of hypoxia-inducible factor-1α in patients with bone tumor: a systematic review and meta-analysis.

BACKGROUND: Recently, many studies have shown the role of hypoxia-inducible factor-1α (HIF-1α) expression in the outcome of bone tumor. However, the results remain inconclusive. It is necessary to carry out a meta-analysis of all the current available data to clarify the relationship between HIF-1α and survival or clinicopathological features of bone tumor. METHODS: PubMed, Cochrane Library, Web of Science, China National Knowledge Internet, and Wanfang databases were used to search the relationship between HIF-1α and bone tumor. Articles investigating clinicopathological and prognostic value of HIF-1α in bone tumor patients were enrolled in this meta-analysis. Overlapping articles, duplicate data, reviews, case reports, and letters without original data were excluded. The pooled risk ratios (RRs) and hazard ratios (HRs) were used to evaluate the clinicopathological and prognostic value of HIF-1α on bone tumor patients, respectively. RESULTS: A total of 28 studies including 1443 patients were included in this meta-analysis, which were involved in three different types of bone tumor including 3 chondrosarcomas, 2 giant cell tumors of bone, and 23 osteosarcomas. Our results showed that high expression levels of HIF-1α were associated with poorer OS (overall survival) (HR = 2.61, 95% CI 2.11-3.23, P <  0.001) and shorter DFS (disease-free survival) (HR = 2.02, 95% CI 1.41-2.89, P <  0.001) in bone tumor. In addition, this study also analyzed the role of HIF-1α expression in clinicopathological features, which were closely related with the severity of bone tumor, including differentiation, clinical stage, metastasis, and microvessel density. Our results indicated that HIF-1α overexpression was significantly associated with differentiation (RR = 1.56, 95% CI 1.00-2.43, P = 0.049), clinical stage (RR = 1.75, 95% CI 1.25-2.45, P = 0.001), metastasis (RR = 1.78, 95% CI 1.58-2.00, P <  0.001), and microvessel density (SMD = 2.34, 95% CI 1.35-3.34, P <  0.001) of bone tumor. CONCLUSIONS: HIF-1α overexpression indicated an unfavorable factor for OS and DFS in bone tumor, suggesting that HIF-1α may serve as a potential prognostic marker for bone tumor.

Identification of TPD52 and DNAJB1 as two novel bile biomarkers for cholangiocarcinoma by iTRAQ­based quantitative proteomics analysis.

Cholangiocarcinoma (CCA) represents a type of epithelial cancer with a late diagnosis and poor outcome. However, the molecular mechanisms responsible for the development of CCA have not yet been fully identified. Thus, in this study, we aimed to elucidate some of these mechanisms. For this purpose, isobaric tags for relative and absolute quantification (iTRAQ) was performed to analyze the secretory proteins from the 2 CCA cell lines, TFK1 and HuCCT1, as well as from a normal biliary epithelial cell line, human intrahepatic biliary epithelial cells (HiBECs). Differentially expressed proteins (DEPs) were identified and biological process analysis was performed according to the Gene Ontology (GO) functional classification annotation and KEGG metabolic pathway map analysis. tumor protein D52 (TPD52) and DnaJ heat shock protein family (Hsp40) member B1 (DNAJB1) were validated using RT­qPCR, western blot analysis and immunohistochemistry. In total, 778 proteins were identified as DEPs. Following validation, TPD52 and DNAJB1 were used for further analysis. The expression levels of TPD52 and DNAJB1 were elevated in CCA cell lines, tissues and bile samples, suggesting that these proteins may contribute to tumor pathogenesis. In addition, the expression levels of TPD52 and DNAJB1 were found to be closely associated with the clinical parameters and prognosis of patients with CCA. On the whole, the findings of this study indicate that TPD52 and DNAJB1 may serve as novel bile biomarkers for CCA.

Correlation Between Tumor Vasculogenic Mimicry and Poor Prognosis of Human Digestive Cancer Patients: A Systematic Review and Meta-Analysis.

Vasculogenic mimicry (VM) is a new pattern of blood supplement independent of endothelial vessels, which is related with tumor invasion, metastasis and prognosis. However, the role of VM in the prognosis of cancer patients is controversial. This study aimed to perform a meta-analysis of the published data to attempt to clarify the prognostic value of VM in the digestive cancer. Relevant studies were retrieved from the PubMed, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure and VIP databases published before March 29, 2018. Studies were included if they detected VM in the digestive cancer and analyzed the overall survival (OS) or disease-free survival (DFS) according to VM status. Two independent reviewers screened the studies, extracted data, and evaluated the quality of included studies with the Newcastle-Ottawa scale. Meta-analysis was performed using STATA 12.0 software. A total of 22 studies with 2411 patients were included in this meta-analysis. Meta-analysis showed that VM was related with the poor OS (HR = 2.30, 95% CI: 2.06-2.56, P < 0.001) and DFS (HR = 2.60, 95% CI: 2.07-3.27, P < 0.001) of patients with digestive cancer. Subgroup analysis showed VM was related with tumor differentiation, lymph node metastasis and TNM stage. Moreover, the present meta-analysis was reliable, and there was no obvious publication bias. This meta-analysis suggested that VM was a poor prognosis of digestive cancer patients. Further large and well-designed studies are required.

The protective effects of triptolide on age-related bone loss in old male rats.

BACKGROUND: Previous studies have showed that triptolide have a critical role in inhibiting osteoclast formation, bone resorption and attenuating regional osteoporosis. However, the protective role of triptolide on age-related bone loss has not been investigated. In the study, we assessed the effect of triptolide supplementation on bone microstructure and bone remolding in old male rat lumbars. METHODS: Fifty-two 22-month-old male Sprague-Dawley rats were randomly assigned to either triptolide treatment group or control group. Triptolide (15 µg/kg/d) or normal saline was administered to the rats of assigned group for 8 weeks. Lumbar bone mineral density (BMD) and bone microstructure were analyzed by micro-CT. Fluorochrome labeling of the bones was performed to measure the mineral apposition rate (MAR) and bone formation rate (BFR). Osteoclast number was also measured by TRAP staining. Plasma level of osteocalcin and tartrate-resistant acid phosphatase 5b (Tracp 5b) was also analyzed. RESULTS: Micro-CT results revealed that triptolide-treated rats had significant higher BMD, bone volume over total volume (BV/TV), trabecular thickness (Tb.Th), bone trabecular number (Tb.N), and lower trabecular separation (Tb.Sp) compared to the control group. Although fluorochrome labeling result showed no significant difference in MAR and BFR between the groups, triptolide decreased osteoclast number in vivo. In addition, a significant higher level of plasma Tracp 5b was observed in the triptolide-treated rats. Furthermore, triptolide also reduced the expression of receptor for activation of NF-κB ligand (RANKL) and increased osteoprotegerin (OPG) expression in the lumbars. CONCLUSION: These results suggested that triptolide had a protective effect on age-related bone loss at least in part by reducing osteoclast number in elder rats. Therefore, triptolide might be a feasible therapeutic approach for senile osteoporosis.

Oncogenic activity of insulin in the development of non-small cell lung carcinoma.

Insulin is associated with the progression of numerous different types of cancer. However, the association between insulin and non-small cell lung carcinoma (NSCLC) remains unknown. The aim of the present study was to evaluate the role of insulin in the proliferation, migration and drug resistance of NSCLC cells, and to determine whether the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway was involved. NSCLC cells were treated with insulin in the absence or presence of LY294002, an inhibitor of the PI3K/Akt pathway. Following co-incubation with insulin, cell proliferation and drug resistance were measured by MTT; cell migration was examined by wound healing and Transwell assays; and the expression of cyclin A, proliferating cell nuclear antigen (PCNA), p27, matrix metalloproteinase 3 (MMP3), P-gp and proteins involved in the PI3K/Akt pathway were assessed via western blotting. The results of the current study demonstrated that insulin enhanced the proliferation, migration and drug resistance of NSCLC cells. Correspondingly, insulin upregulated the expression of cyclin A, PCNA, MMP3, P-gp and downregulated p27 expression in NSCLC cells. Following treatment with insulin, it was demonstrated that phospho-Akt expression increased in a dose-dependent manner. However, the effects of insulin on NSCLC cells was inhibited by the PI3K/Akt pathway inhibitor LY294002. Therefore, the results of the current study indicate that insulin is associated with the development of NSCLC by activating the PI3K/Akt pathway. This may improve understanding of the mechanism of action of insulin in NSCLC in the future.

Magnolol suppresses the proliferation and invasion of cholangiocarcinoma cells via inhibiting the NF-κB signaling pathway.

BACKGROUND: Magnolol has shown the potential anticancer properties against a variety of cancers. However, the role of magnolol in cholangiocarcinoma (CCA) cells is unknown. In this study, we assessed the effect of magnolol on the CCA cells. METHODS: CCA cells were treated with magnolol in the absence or presence of TNFα, the activator for NF-κB. After co-incubation with magnolol, cell proliferation and growth were examined by MTT, colony formation and xenograft tumors; cell cycle was analyzed by flow cytometry; cell migration and invasion were detected by wound healing and transwell assays; the expression of PCNA, Ki67, CyclinD1, MMP-2, MMP-7 and MMP-9 and NF-κB pathway were evaluated by using Western blot. RESULTS: Magnolol inhibited the abilities of CCA cell growth, migration and invasion accompanying with a decreased expression of PCNA, Ki67, MMP-2, MMP-7 and MMP-9 (all P<0.05). TREATMENT: with magnolol induced cell cycle arrest in G1 phase with a downregulation of cell cycle protein CyclinD1 (all P<0.05). In addition, magnolol suppressed the expression of p-IκBα and p-P65 and the effect of magnolol on CCA cells could be inhibited by TNFα. CONCLUSIONS: Magnolol could inhibit the growth, migration and invasion of CCA cells through regulation of NF-κB pathway, and these data indicate that magnolol is a potential candidate for treating of CCA.

Oncogenic retinoic acid receptor α promotes human colorectal cancer growth through simultaneously regulating p21 transcription and GSK3ß/ß-catenin signaling.

Retinoic acid receptor α (RARα) plays important roles in the progression of several cancers such as leukemia, breast cancer, and lung cancer. In this study, we demonstrated that RARα protein was frequently overexpressed in human CRC specimens and CRC cell lines. RARα knockdown decreased cell survival, proliferation, and colony formation in vitro and tumorigenic potential in nude mice. Specifically, RARα knockdown inhibited cell cycle progression at G1 phase through upregulation of cell cycle inhibitor p21, and downregulation of cyclinD1. Furthermore, RARα was directly recruited to the p21 promoter to inhibit the expression of p21. Simultaneously, RARα contributed to the progression of CRC cells in part due to upregulation of cyclinD1 via activation of GSK3ß/ß-catenin pathway. Molecular mechanism studies revealed RARα interacted with GSK3ß and led to decreased expression of GSK3ß at ser9, followed by increased ß-catenin expression. Taken together, our results signified the importance of RARα in CRC and demonstrated that RARα promotes CRC progression through suppressing p21 transcription and enhancing GSK3ß/ß-catenin signaling. RARα might become a potential molecular target for the treatment of CRC.

Positive feedback loop of IL-1ß/Akt/RARα/Akt signaling mediates oncogenic property of RARα in gastric carcinoma.

Abnormal expression and function of retinoic acid receptor α (RARα) have been reported to be associated with various cancers including acute promyelocytic leukemia and hepatocellular carcinoma. However, the role and the mechanism of RARα in gastric carcinoma (GC) were unknown. Here, the expression of RARα was frequently elevated in human GC tissues and cell lines, and its overexpression was closely correlated with tumor size, lymph node metastasis and clinical stages in GC patients. Moreover, RARα overexpression was related with pathological differentiation. Functionally, RARα knockdown inhibited the proliferation and metastasis of GC cells, as well as enhanced drug susceptibility both in vitro and in vivo. Additionally, RARα knockdown suppressed GC progression through regulating the expression of cell proliferation, cell cycle, invasion and drug resistance associated proteins, such as PCNA, CyclinB1, CyclinD2, CyclinE, p21, MMP9 and MDR1. Mechanistically, the above oncogenic properties of RARα in GC were closely associated with Akt signaling activation. Moreover, overexpression of RARα was induced by IL-1ß/Akt signaling activation, which suggested a positive feedback loop of IL-1ß/Akt/RARα/Akt signaling in GC. Taken together, we demonstrated that RARα was frequently elevated in GC and exerted oncogenic properties. It might be a potential molecular target for GC treatment.

Upregulation of retinoic acid receptor-ß reverses drug resistance in cholangiocarcinoma cells by enhancing susceptibility to apoptosis.

Retinoic acid receptor ß (RARß), a known tumor suppressor gene, is frequently silenced in numerous malignant types of tumor. Recent reports have demonstrated that loss of RARß expression may be responsible, in part, for the drug resistance observed in clinical trials. However, little is known about the role of RARß in regulating drug sensitivity in patients with cholangiocarcinoma (CCA) with a high risk of mortality and poor outcomes. In the present study, low RARß expression was observed in the majority of CCA tissues investigated (28/33, 84.8%). In addition, the CCA cell line QBC939, which exhibits low RARß expression, was found to be significantly resistant to chemotherapeutic agents compared with SK­ChA­1, MZ­ChA­1 and Hccc9810 CCA cell lines, which exhibit high RARß expression. Furthermore, upregulation of RARß significantly enhanced the sensitivity of QBC939 cells to common chemotherapeutic agents both in vitro and in vivo. Upregulation of RARß was shown to increase the expression of proapoptotic genes bax, bak and bim, in addition to caspase­3 activity, and decrease the expression of antiapoptotic genes bcl­2, bcl­xL and mcl­1. As a result, CCA cells were more susceptible to caspase­dependent apoptosis. Taken together, these data suggest that RARß upregulation rendered CCA cells more sensitive to chemotherapeutic agents by increasing the susceptibility of cells to caspase-dependent apoptosis. These results support the hypothesis that RARß may be an ideal chemosensitization target for the treatment of patients with drug-resistant CCA.

IL-1ß induced RXRα overexpression through activation of NF-κB signaling in gastric carcinoma.

BACKGROUND: Abnormal expression of Retinoid X Receptor α (RXRα) seems to be a frequent incident in a variety of cancers. However, the expression pattern and the mechanisms in gastric carcinoma (GC) remain unclear. METHODS: In GC tissues and cell lines, the expression levels of RXRα mRNA and protein were detected by Q-PCR and Western blot, respectively; the localization of RXRα was evaluated by immunohistochemistry (IHC) or immunocytochemistry (ICC). The effect of IL-1ß on RXRα expression and localization was detected by Western blot and ICC. Nuclear factor-κB (NF-κB) pathway was assessed via Western blot. RESULTS: RXRα expression was markedly elevated at both mRNA and protein levels in GC tissues and cell lines (all P<0.05). The abnormal overexpression of RXRα was predominantly visualized in cytoplasm. IL-1ß significantly induced cytoplasmic expression of RXRα in a time-dependent manner. Co-incubation with IL-1ß enhanced phospho-IKKα (p-IKKα) expression and this effect could be inhibited by the specific inhibitor for NF-κB (all P<0.01). CONCLUSIONS: IL-1ß upregulated RXRα through activation of NF-κB signaling and these suggested a possible clinic significance of retinoid receptor expression in the diagnosis and treatment of GC.