Downregulation of DHRS9 expression in colorectal cancer tissues and its prognostic significance.

Dehydrogenase/reductase (SDR family) member 9 (DHRS9) is aberrantly expressed in colorectal cancer (CRC), but its prognostic value is unknown. The aim of the work was to investigate the prognostic significance of DHRS9 expression in CRC. We found that DHRS9 was frequently downregulated in CRC clinical samples at both the messenger RNA (mRNA) and protein levels. Decreased expression of DHRS9 was significantly correlated with increased lymph node metastasis (p = 0.032), advanced tumor-node-metastasis (TNM) stage (p = 0.021), increased disease recurrence (p = 0.001), and death (p = 0.014). Kaplan-Meier analysis indicated that low DHRS9 expression predicted poor disease-free survival (p = 0.003) and disease-specific survival (p = 0.021). Cox multivariate analysis revealed that reduced expression of DHRS9 was an independent unfavorable prognostic indicator for CRC. Furthermore, combination of DHRS9 with TNM stage was a more powerful predictor of poor prognosis than either of the two parameters alone. Our results suggest that decreased expression of DHRS9 correlates with tumor progression and may serve as a potential prognostic biomarker in CRC.

Overexpression of SULT2B1b is an independent prognostic indicator and promotes cell growth and invasion in colorectal carcinoma.

Aberrant expression of cytosolic sulfotransferase 2B1b (SULT2B1b) has been reported in several human malignancies. However, the expression pattern and clinical significance of SULT2B1b in colorectal carcinoma (CRC) remains unknown. Real-time quantitative PCR, western blot, and immunohistochemistry analyses were used to determine SULT2B1b expression in CRC clinical samples and CRC-derived cell lines. Kaplan-Meier and Cox proportional regression analyses were used to evaluate the association between SULT2B1b expression and patient survival in two independent cohorts of 485 patients with CRC. Gain- and loss-of-function approaches were employed to investigate the role of SULT2B1b in regulation of CRC cell growth and invasion. We found that SULT2B1b expression was frequently upregulated in CRC clinical samples and CRC-derived cell lines and was significantly correlated with lymph node metastasis and TNM stage in both the training and validation cohorts. Patients with higher intratumoral SULT2B1b expression had a significantly shorter disease-specific survival (DSS) and disease-free survival (DFS) than those with lower expression. Importantly, increased expression of SULT2B1b significantly predicted poor DSS and DFS and was an independent unfavorable prognostic indicator for stage II patients in both cohorts. Functional studies revealed that overexpression of SULT2B1b promoted CRC cell growth and invasion in vitro. Conversely, knockdown of SULT2B1b inhibited these processes. In conclusion, our findings suggest that SULT2B1b expression correlates with disease progression and metastasis and may serve as a novel prognostic biomarker and potential therapeutic target for patients with CRC.

Serine threonine tyrosine kinase 1 is a potential prognostic marker in colorectal cancer.

BACKGROUND: Aberrant expression of serine threonine tyrosine kinase 1 (STYK1) has been reported in several human malignancies including colorectal cancer (CRC). However, the prognostic significance of STYK1 expression in CRC remains unknown. METHODS: STYK1 protein expression in paraffin-embedded CRC specimens was determined immunohistochemically. The correlation of STYK1 expression with clinicopathologic features was assessed in a cohort containing 353 patients with primary CRC. Kaplan-Meier and Cox proportional regression analyses were used to evaluate the association between STYK1 expression and patients' survival. RESULTS: STYK1 expression was frequently up-regulated in CRC clinical samples at the protein levels and was significantly associated with tumor differentiation grade (p = 0.030), lymph node metastasis (p = 0.004), TNM stage (p = 0.007) and patient death (p < 0.001). Kaplan-Meier analysis indicated that patients with high intratumoral STYK1 expression had a significantly shorter disease-specific survival (DSS) than those with low expression (p < 0.001). Importantly, high levels of STYK1 protein predicted poor DSS for both stage II (p < 0.001) and stage III (p = 0.004) patients. Furthermore, multivariate analyses revealed that STYK1 protein expression was an independent prognostic indicator for both stage II (hazard ratio [HR], 2.472; p = 0.001) and stage III (HR, 2.001; p = 0.004) patients. CONCLUSIONS: Our results suggest that increased STYK1 protein expression correlates with disease progression and metastasis and may serve as a predictor of poor survival in CRC.

Upregulation of NETO2 expression correlates with tumor progression and poor prognosis in colorectal carcinoma.

BACKGROUND: Neuropilin and tolloid-like 2 (NETO2) has been found to be overexpressed in different human cancers, but its expression pattern and clinical relevance in colorectal carcinoma (CRC) remains unknown. METHODS: Real-time quantitative PCR, western blot and immunohistochemistry analyses were used to analyze the expression of NETO2 in CRC clinical samples. The correlation of NETO2 expression with clinicopathologic features was estimated in a cohort containing 292 patients with primary CRC. Kaplan-Meier and Cox proportional hazards regression analyses were used to assess the prognostic value of NETO2 expression in CRC. RESULTS: The expression of NETO2 was frequently upregulated in CRC clinical samples at both the mRNA and protein levels, and its upregulation was significantly correlated with poor tumor differentiation (p = 0.013), advanced local invasion (p = 0.049), increased lymph node metastasis (p = 0.009), advanced TNM stage (p = 0.041) and increased patient death (p = 0.001). Kaplan-Meier analysis of the complete study cohort revealed that patients with high-NETO2 tumors had a significantly shorter disease-specific survival (DSS) than those with low-NETO2 tumors (p < 0.001). Importantly, high levels of NETO2 protein predicted poor DSS for patients with early stage tumors (p = 0.027) and for those with advanced stage tumors (p = 0.020). Furthermore, multivariate analyses indicated that increased NETO2 expression was an independent unfavorable prognostic factor for patients with early stage tumors (hazard ratio [HR] = 1.937, 95% CI = 1.107-3.390, p = 0.021) as well as patients with advanced stage tumors (HR = 2.241, 95% CI = 1.245-4.035, p = 0.007). CONCLUSIONS: Our findings suggest that NETO2 upregulation could serve as a potential biomarker for the prediction of advanced tumor progression and unfavorable prognosis in patients with CRC.

Prognostic value of carbonic anhydrase VII expression in colorectal carcinoma.

BACKGROUND: Carbonic anhydrases (CAs) have been implicated in the pathogenesis of human cancers. Carbonic anhydrase VII (CA7), a member of the CA gene family, was recently demonstrated to be expressed in several human tissues including colon. Nevertheless, the expression and clinical relevance of CA7 in colorectal carcinoma (CRC) has not been investigated. METHODS: Real-time PCR, western blot, and immunohistochemistry analyses were used to determine CA7 expression in CRC clinical samples. The correlation of CA7 expression with clinicopathologic features was assessed in 228 patients from Luoyang, China (training cohort) and validated in 151 patients from Shanghai, China (validation cohort). Kaplan-Meier and Cox proportional regression analyses were used to estimate the association between CA7 expression and patients' survival. RESULTS: CA7 expression was frequently downregulated in CRC tissues at both the mRNA and protein levels. Reduced expression of CA7 was significantly correlated with poor differentiation, positive lymph node metastasis, advanced TNM stage and unfavorable clinical outcome not only in the training cohort but also in the validation set. Survival analysis indicated that patients with lower CA7 expression had a significantly shorter disease-specific survival (DSS) than those with higher CA7 expression. Importantly, further stage-based analyses revealed that decreased CA7 expression significantly predicted poor DSS and was an independent adverse prognostic indicator for patients with early stage tumors in both cohorts. CONCLUSIONS: Our results indicate that decreased expression of CA7 correlates with disease progression and predicts poor prognosis in CRC, especially for patients with early stage tumors.

Signal regulatory protein α negatively regulates mast-cell activation following FcεRI aggregation.

Mast cells elicit allergic reaction through degranulation and release of proinflammatory mediators after aggregation of the IgE receptor FcεRI. Here we provide evidence to show that signal regulatory protein α (SIRPα), an ITIM-containing receptor, is an endogenous regulator of IgE-Ag induced mast-cell activation. SIRPα expression is promptly reduced in mast cells in response to FcεRI aggregation. Impaired expression of SIRPα in mast cells facilitates FcεRI-evoked degranulation and de novo synthesis of cytokines (IL-4, IL-13, IL-6, and TNF-α). We further demonstrate that SIRPα knockdown in mast cells accelerates calcium mobilization and affects cytoskeletal rearrangement (F-actin disassembly and polymeric tubulin formation) after FcεRI aggregation. Mechanistic studies highlight the prolonged activation of NF-κB and MAPKs as well as PLC-γ after FcεRI stimulation as a consequence of the inhibition of SIRPα expression in mast cells. Immunoprecipitation analysis shows that SIRPα knockdown markedly increases IgE-induced SHP2 interaction with PI3K regulatory subunit PI3Kp85 or IKK-ß in mast cells, indicating that SIRPα may accomplish this through its association and sequestration of SHP2. Collectively, our results strongly indicate that SIRPα is a biological important regulator of FcεRI signaling.

Inhibition of active autophagy induces apoptosis and increases chemosensitivity in cholangiocarcinoma.

Intrahepatic cholangiocellular carcinomas (ICCs) are usually fatal neoplasms originating from bile duct epithelia. However, many cholangiocarcinoma cells are shown to be resistant to chemotherapeutic drugs, which induce cell apoptosis. The role of autophagy and the therapeutic value of autophagy-associated genes are largely unknown in ICC. Here, we showed that autophagy was activated in nutrient starvation and xenograft cholangiocarcinoma cells. Furthermore, expression of autophagic genes and their autophagic activity were higher in clinical ICC specimens than that in normal cholangiocytes separated by laser capture microdissection. Inhibition of autophagy by autophagy inhibitors or siRNA, cholangiocarcinoma cells showed detention of proliferation and increase of apoptosis during nutrient starvation. In addition, autophagy inhibitor treatment or knockdown of beclin 1 suppressed tumor growth and sensitized ICC cells to chemotherapeutic agent-induced cell death. In conclusion, our data showed that autophagy is activated in ICC, and inactivation of autophagy may lead to cell apoptosis and enhance chemotherapy sensitivity.

Overexpression of CHKA contributes to tumor progression and metastasis and predicts poor prognosis in colorectal carcinoma.

Aberrant expression of choline kinase alpha (CHKA) has been reported in a variety of human malignancies including colorectal carcinoma (CRC). However, the role of CHKA in the progression and prognosis of CRC remains unknown. In this study, we found that CHKA was frequently upregulated in CRC clinical samples and CRC-derived cell lines and was significantly correlated with lymph node metastasis (p = 0.028), TNM stage (p = 0.009), disease recurrence (p = 0.004) and death (p < 0.001). Survival analyses indicated that patients with higher CHKA expression had a significantly shorter disease-free survival (DFS) and disease-specific survival (DSS) than those with lower CHKA expression. Multivariate analyses confirmed that increased CHKA expression was an independent unfavorable prognostic factor for CRC patients. In addition, combination of CHKA with TNM stage was a more powerful predictor of poor prognosis than either parameter alone. Functional study demonstrated that knockdown of CHKA expression profoundly suppressed the growth and metastasis of CRC cells both in vitro and in vivo. Mechanistic investigation revealed that EGFR/PI3K/AKT pathway was essential for mediating CHKA function. In conclusion, our results provide the first evidence that CHKA contributes to tumor progression and metastasis and may serve as a novel prognostic biomarker and potential therapeutic target in CRC.

Gankyrin has an antioxidative role through the feedback regulation of Nrf2 in hepatocellular carcinoma.

Oxidative stress status has a key role in hepatocellular carcinoma (HCC) development and progression. Normally, reactive oxygen species (ROS) levels are tightly controlled by an inducible antioxidant program that responds to cellular stressors. How HCC cells respond to excessive oxidative stress remains elusive. Here, we identified a feedback loop between gankyrin, an oncoprotein overexpressed in human HCC, and Nrf2 maintaining the homeostasis in HCC cells. Mechanistically, gankyrin was found to interact with the Kelch domain of Keap1 and effectively competed with Nrf2 for Keap1 binding. Increased expression of gankyrin in HCC cells blocked the binding between Nrf2 and Keap1, inhibiting the degradation of Nrf2 by proteasome. Interestingly, accumulation and translocation of Nrf2 increased the transcription of gankyrin through binding to the ARE elements in the promoter of gankyrin. The positive feedback regulation involving gankyrin and Nrf2 modulates a series of antioxidant enzymes, thereby lowering intracellular ROS and conferring a steadier intracellular environment, which prevents mitochondrial damage and cell death induced by excessive oxidative stress. Our results indicate that gankyrin is a regulator of cellular redox homeostasis and provide a link between oxidative stress and the development of HCC.

RMP predicts survival and adjuvant TACE response in hepatocellular carcinoma.

Adjuvant transcatheter arterial chemoembolization (TACE) protects against hepatocellular carcinoma (HCC) and is associated with reduced disease recurrence and improved outcome after surgery. However, deterioration of liver function after TACE negatively impacts the patient prognosis and limits it use as an option to prolong survival. We analyzed two independent cohorts that included a total of 510 patients with HCC who had undergone tumor resection. Immunohistochemistry assay was used to measure RPB5-mediating protein (RMP) expression and assessed their association with recurrence rate and response to therapy with adjuvant TACE. In patients with HCC, the expression of RMP in tumor is associated with age, gender, tumor size, portal venous invasion, TNM stages, BCLC stages and overall survival. Among patients with high RMP expression, adjuvant TACE after resection was associated with early recurrence. Even in the patients with small tumor size (no more than 5 cm) or no venous invasion, RMP status is associated with response to adjuvant TACE. RMP status in tumors may be a useful marker in estimating prognosis in patients with HCC and in assisting in the selection of patients who are likely to benefit from adjuvant TACE to prevent relapse.

Cloning of the BPLA(2) Gene from Agkistrodon halys Pallas.

First strand cDNA synthesis was primed with synthetic oligonucleotide from total RNA extracted from the gland of the snake Agkistrodon halys Pallas. The pro-BPLA(2) gene was then amplified by PCR and cloned into the pBS-ks vector. Its nucleotide sequence has been determined by analyzing the DNA sequence of three colonies containing the pro-BPLA(2) gene. The deduced amino acid sequence consists of 138 amino acids and agrees with the partly known amino acid sequence except for seven amino acid residues. The successful cloning of the BPLA(2) gene not only has made the determination of its total amino acid sequence possible, but also provided a good basis for further research work in the protein engineering of functional peptides from snakes.

Research on the Diversity of PLA(2) Gene from Agkistrodon halys Pallas.

We used degenerate primers to amplify phospholipase A(2)(PLA(2)) gene by RT-PCR from venom total RNA of Agkistrodon halys Pallas, and screened with B-PLA(2) gene as probe. Finally we isolated three cDNAs containing A-PLA(2) and two other genes showing similar characteristic structure--Asn(49)-PLA(2) and BA-PLA(2). Their complete sequence was determined by bidirectional sequencing and their amino acid sequence was deduced. The amino acid sequence of A-PLA(2) deduced from the cDNA agreed with that determined by protein sequencing except for four residues; Asn(49 )-PLA(2) and B-PLA(2) are very alike (up to 95%), but the Asp(49)-PLA(2) of B-PLA(2) involved in the enzyme reaction is replaced by Asn(49) of Asn(49)-PLA(2). Therefore, it possibly affects the enzyme reaction of Asn(49)-PLA(2). The N-terminus sequence of BA-PLA(2) is highly homologous to B-PLA(2), but its C-terminus sequence is almost the same as A-PLA(2). The successful cloning of these isoenzyme genes not only discloses the structure diversity of PLA(2)(namely DNA modification and recombination), but also provides excellent material for the study of structure-function relationship in PLA(2).

Expression of the APLA(2) Gene from Agkistrodon halys Pallas.

The APLA(2) gene from Agkistrodon halys Pallas has been cloned into the expression plasmid pBLMVL2 and expressed in E. coli RR1. The molecular weight of the expressed product is approximately 14 kD as shown by SDS-PAGE, its expression level is about 30% of the total cellular proteins. The protein was produced as insoluble inclusion bodies. After partially purified by washing the inclusion bodies, the product was denatured and refolded into active form. Then, the expressed APLA(2) was purified by FPLC Superose (TM) 12 and was a single band as shown by SDS-PAGE. The purified expressed protein had specific activity as the native enzyme and cross-reacted with antisera prepared against the native enzyme. The successful expression of the APLA(2) gene from Agkistrodon halys Pallas provides a good basis for further structure-function studies.

The prognostic significance and therapeutic potential of hedgehog signaling in intrahepatic cholangiocellular carcinoma.

PURPOSE: The correlation of the hedgehog signaling pathway with the progression, prognosis, and therapeutics of intrahepatic cholangiocellular carcinoma (ICC) has not been well documented. The study aimed to investigate the expression, prognostic significance, and therapeutic value of hedgehog components in ICC. EXPERIMENTAL DESIGN: Two independent cohorts of 200 patients with ICC were enrolled. By real-time PCR and immunohistochemistry assay, hedgehog components expression was evaluated. The prognostic values of hedgehog proteins were identified and verified. Cyclopamine or siRNA-targeting Gli was used to block the hedgehog signaling. Cell proliferation and apoptosis were observed by CCK8, cell cycle, and annexin V staining assays. In vivo murine tumor model was used to evaluate the role of hedgehog in ICC. RESULTS: In ICC tissues, the Gli1 nuclear immune-intensity was associated with intrahepatic metastasis and the expression of Gli2 was associated with intrahepatic metastasis, venous invasion, and Unio Internationale Contra Cancrum (UICC) pT characteristics. In survival analysis, high Gli1 or Gli2 expressers had an unfavorable overall survival (OS) prognosis and a shorter disease-free survival (DFS) than those with low expression. In multivariate analysis, Gli1 expression was found to be an independent prognostic factor of OS, which was validated by another independent cohort. Furthermore, blocking the hedgehog signaling by cyclopamine or siRNA-targeting Gli1 resulted in apoptosis and growth inhibition in ICC cells. CONCLUSIONS: This study shows, for the first time, activation of hedgehog pathway associated with the progression and metastasis in ICC, which may provide prognostic and therapeutic values for this tumor.

The oncoprotein p28GANK establishes a positive feedback loop in ß-catenin signaling.

p28(GANK) (also known as PSMD10 or gankyrin) is a novel oncoprotein that is highly expressed in hepatocellular carcinoma (HCC). Through its interaction with various proteins, p28(GANK) mediates the degradation of the tumor suppressor proteins Rb and p53. Although p53 was reported to downregulate ß-catenin, whether p28(GANK) is involved in the regulation of ß-catenin remains uncertain. Here we report that both growth factors and Ras upregulate p28(GANK) expression through the activation of the phosphoinositide 3-kinase-AKT pathway. Upregulation of p28(GANK) expression subsequently enhanced the transcription activity of ß-catenin. This effect was observed in p53-deficient cells, suggesting a p53-independent mechanism for the p28(GANK)-mediated activation of ß-catenin. p28(GANK) overexpression also reduced E-cadherin protein levels, leading to increased release of free ß-catenin into the cytoplasm from the cadherin-bound pool. Interestingly, exogenous expression of p28(GANK) resulted in elevated expression of the endogenous protein. We also observed that both ß-catenin and c-Myc were transcriptional activators of p28(GANK), and a correlation between p28(GANK) overexpression and c-Myc, cyclin D1 and ß-catenin activation in primary human HCC. Together, these results suggest that p28(GANK) expression is regulated by a positive feedback loop involving ß-catenin, which may play a critical role in tumorigenesis and the progression of HCC.

p28GANK inhibits endoplasmic reticulum stress-induced cell death via enhancement of the endoplasmic reticulum adaptive capacity.

It has been shown that oncoprotein p28(GANK), which is consistently overexpressed in human hepatocellular carcinoma (HCC), plays a critical role in tumorigenesis of HCC. However, the underlying mechanism remains unclear. Here, we demonstrated that p28(GANK) inhibits apoptosis in HCC cells induced by the endoplasmic reticulum (ER) stress. During ER stress, p28(GANK) enhances the unfolded protein response, promotes ER recovery from translational repression, and thereby facilitates cell's ability to cope with the stress conditions. Furthermore, p28(GANK) upregulates glucose-regulated protein 78 (GRP78), a key ER chaperone protein, which subsequently enhances the ER folding capacity and promotes recovery from ER stress. We also demonstrated that p28(GANK) increases p38 mitogen-activated protein kinase and Akt phosphorylation, and inhibits nuclear factor kappa B (NF-kappaB) activation under ER stress, which in turn contributes to GRP78 upregulation. Taken together, our results indicate that p28(GANK) inhibits ER stress-induced apoptosis in HCC cells, at least in part, by enhancing the adaptive response and GRP78 expression. We propose that p28(GANK) has potential implications for HCC progression under the ER stress conditions.