Downregulation of Rab23 inhibits hepatocellular carcinoma by repressing SHH signaling pathway.

Hepatocellular carcinoma (HCC) is the sixth most common malignant tumors and the third leading cause of cancer-related death worldwide. As an oncogene, Rab23 has been shown to be significantly related to the growth and migration of hepatocellular carcinoma in both in vitro and in vivo studies, but its underlying mechanism remains obscure. In the present study, we examined the effect of inhibiting Rab23 expression on the pathological progression of HCC. The correlation between liver Rab23 gene expression and survival probability in human HCC patients was analyzed using the TCGA database and CPTAC database. Rab23 knockdown hepatocellular carcinoma cell line was generated through lentiviral transduction, then we established a nude HCC xenograft model by subcutaneously implanting the transfected cells. The analysis of gene and protein expression was carried out using Western blot or RT-qPCR, respectively. Flow cytometry analysis was used to detect the level of apoptosis. The expression levels of key proteins involved in the Sonic Hedgehog (SHH) signaling pathway were assessed. The results showed that HCC patients with low levels of hepatic Rab23 mRNA and protein had a better survival tendency than those with higher levels of Rab23. Cell proliferations were reduced and apoptosis levels were increased after Knocking down Rab23 in HCC cell lines. Furthermore, in vivo studies have demonstrated that suppression of the Rab23 gene results in decreased tumor size, proliferation rate, and reduced levels of SHH-related proteins Smoothened and GLI-1. The above results suggest that Rab23 is involved in the pathological progression of HCC as an important regulator of the SHH signaling pathway, which also provides an important research basis for new therapeutic strategies for HCC.

Reliability and variability in the interpretation of lumbar high intensity zone.

OBJECTIVE: The aim of this study was to evaluate the reliability of high intensity zone (HIZ) and to assess discrepancy in the interpretation, as well as investigate the effects of parameters of HIZ on interobserver variation. METHODS: Four spine surgeons made independent observations on lumbar magnetic resonance imaging (MRI) from 207 consecutive patients from 3 institutions. The κ statistic was used to characterize inter- and intraobserver reliability for visual assessments of HIZ. The corresponding MRI was provided to 2 additional spine surgeons for quantitative measurements. The parameters of HIZ, including signal intensity (SI) and area ratio (HIZ%), were used to assess the interobserver variation of HIZ. RESULTS: The overall interobserver agreement for visual assessments was substantial (κ=0.62 at L4-5 and 0.61 at L5-S1), and intraobserver agreement was excellent (κ=0.84 at L4-5 and 0.86 at L5-S1). Of 93 observed HIZ, 17 instances (18.3%) were agreed upon by all visual observers. The SI with full agreement was significantly brighter than all the others (p<0.01). The HIZ% with 2 agreements was significantly smaller than those with 4 agreements (p=0.04) and 3 agreements (p=0.03). Although fewer observers with consensus were associated with smaller HIZ%, the difference was not significant (p>0.05). CONCLUSION: The reliability in the interpretation of HIZ was sufficient for spine surgeons with differing levels of experience. This study highlighted that signal intensity was the primary cause of variability in visual observation.

Sublocalization of Rab23, a mediator of Sonic hedgehog signaling pathway, in hepatocellular carcinoma cell lines.

The novel member of the Rab family of GTPases, Rab23, is an essential negative regulator of the Sonic hedgehog (Shh) signaling pathway. Loss of function mutation of the Rab23 gene causes abnormal development of the neural tube in mice and in certain human congenital diseases. The aberrant overexpression of Rab23 has been associated with various diseases, such as gastric, hepatocellular and lung cancer. The exact function of Rab23 in hepatocellular carcinomas (HCCs), however, remains unknown. Previously, we reported the abnormal sublocalization of Rab23 in lung cancers. In the current study, we investigated the role of Rab23 in HCCs. We report the distinct sublocalization pattern of Rab23 in HCC cell lines. This difference depends on the GDP/GTP-binding form, and inhibition of the Rab23 cycle decreases the expression and nuclear localization of Gli1.

Modified straight leg raising test: a hypothetical clinical adjunct to distinguish two types of lumbar disc herniation preoperatively.

There are two anatomically different types of lumbar disc herniation, contained and noncontained. The status of disc herniation not only has a place of in planning therapeutic procedure, but also appears prognostically important. However, it is difficult to distinguish these two types completely without surgery, even by imaging studies. As a hypothetical clinical adjunct, a modified straight leg raising test is described. This novel diagnostic aid is based on the pathogenesis of sciatica, and enlightened by the mechanisms of both traditional straight leg raising test and traction. We surmise that the mechanical compression caused by herniated disc is predominant in contained type; whereas the chemical inflammatory effect is more pronounced in the pathogenesis of sciatica in noncontained type. Thus, it is hypothesized that in patients with contained type, the symptoms of sciatica, and the angles of straight leg raising test would be different before and after traction. On the other hand, in patients with noncontained type, these clinical appearances could not improve significantly. According to the different symptoms, two types of disc herniation are expected to be distinguished by the straight leg raising test preoperatively. Combined with imaging studies, this hypothetical clinical adjunct is hoped to ameliorate the accuracy of diagnosis.

Green tea polyphenol epigallocatechin-3-gallate inhibits oxidative damage and preventive effects on carbon tetrachloride-induced hepatic fibrosis.

The aim of the study was to examine the effects of epigallocatechin-3-gallate (EGCG) on hepatic fibrogenesis and on cultured hepatic stellate cells (HSCs). The rat model of carbon tetrachloride (CCl(4))-induced hepatic fibrosis was used to assess the effect of daily intraperitoneal injections of EGCG on the indexes of fibrosis. Histological and hepatic hydroxyproline examination revealed that EGCG significantly arrested progression of hepatic fibrosis. EGCG caused significant amelioration of liver injury (reduced activities of serum alanine aminotransferase and aspartate aminotransferase). The development of CCl(4)-induced hepatic fibrosis altered the redox state with a decreased hepatic glutathione and increased the formation of lipid peroxidative products, which were partially normalized by treatment with EGCG, respectively. Moreover, EGCG markedly attenuated HSC activation as well as matrix metalloproteinase (MMP)-2 activity. In cultured stellate cell, the expression of MMP-2 mRNA and protein were substantially reduced by EGCG treatment. Concanavalin A-induced activation of secreted MMP-2 was inhibited by EGCG through the influence of membrane type 1-MMP activity. These results demonstrate that administration of EGCG may be useful in the treatment and prevention of hepatic fibrosis.

Rab23 is a potential biological target for treating hepatocellular carcinoma.

AIM: To elucidate the role of Rab23 in hepatocellular carcinoma (HCC) by assessing the expression of Rab23 in HCC tissue and in HCC cell lines. METHODS: Primary tumors (n = 100) were stained with Rab23 antibodies using immunohistochemistry and in situ hybridization in tissue microarrays. Relationships between gene expression and pathology parameters were analysed. The biological significance of Rab23 in Hep-3B cells was examined by knocking down Rab23 gene expression. We designed a pair of double-stranded RNAs against human rab23 and transfected siRNA into Hep-3B cells. Rab23 expression in these cells was examined using RT-PCR and Western blots. We investigated cell growth by MTT assays and fluorescence-activated cell sorting. RESULTS: High cytoplasmic and nuclear expression of Rab23 was found in 38 of 71 (53.5%) and in 49 of 68 HCC patients (72%) respectively, which correlated with tumor size. HCC cell lines expressed Rab23. In Hep3B cells, siRNA for Rab23 decreased Rab23 mRNA by 4.5-fold and protein expression by 2-fold. Survival rates at 24 and 48 h for Hep-3B cells transfected with siRNA were lower and about 30% Hep-3B cells were apoptotic. Knocking down rab23 suppressed Hep3B cell growth, suggesting that rab23 could play an important role in Hep3B cell growth. CONCLUSION: Rab23 is overexpressed and/or activated in HCC. Rab23 may be both a HCC predictor and a target for treating HCC.

[Correlations of expressions of macrophage migration inhibitor factor and cyclin D1 with tumor size and metastasis of hepatocellular carcinoma].

OBJECTIVE: To explore the possible relationship between the expressions of macrophage migration inhibitor factor (MIF), cyclin D1, cyclin-dependent kinase 4 (CDK4), phosphorylated-retinoblastoma susceptibility gene product Rb protein (phospho-Rb) and the development of hepatocellular carcinoma (HCC). METHODS: 93 HCC tissues and 5 normal liver tissues were used to investigate the expressions of MIF, cyclin D1, CDK4 and phospho-Rb by tissue microarray and immunohistochemistry methods. RESULTS: The expression rates of MIF, cyclin D1, CDK4 and phospho-Rb in the HCC tissues were 71%, 41%, 82% and 14% respectively, and in the normal liver tissues, they were 0%, 0%, 80% and 20% respectively. The expression rates of MIF and cyclin D1 were significantly different between the tumor and the normal liver tissues and the expression rates of CDK4 and phospho-Rb were not significantly different between the tumor and the normal liver tissues. The rate difference (69% versus 48%) of MIF expression between the larger tumors (> 3.5 cm) and the smaller tumors (< 3.5 cm) was of statistical significance (P < 0.01). The expression rate (62%) of cyclin D1 in the tumors with metastasis was significantly higher than the expression rate (35%) in the tumors without metastasis (P < 0.05). MIF expression was positively correlated with cyclin D1 expression in the tumor tissues (P < 0.01). CDK4 and phospho-Rb expressions were not significantly associated with the tumor sizes and metastasis status. CONCLUSION: Our results indicate that MIF and cyclin D1 might be related to the growth and metastasis of HCC.

Green tea polyphenol epigallocatechin-3-gallate suppresses rat hepatic stellate cell invasion by inhibition of MMP-2 expression and its activation.

AIM: Epigallocatechin-3-gallate (EGCG) is the major component of green tea polyphenols, whose wide range of biological properties includes anti-fibrogenic activity. Matrix metalloproteinases (MMP) that participate in extracellular matrix degradation are involved in the development of hepatic fibrosis. The present study investigates whether EGCG inhibits activation of the major gelatinase matrix metalloproteinase-2 (MMP-2) in rat hepatic stellate cells (HSC). METHODS: The expression of MMP-2, tissue inhibitors of metalloproteinases-2 (TIMP-2), and membrane-type 1-MMP (MT1-MMP) was assessed by RT-PCR and Western blot analyses. MMP-2 activity was evaluated by zymography and MT1-MMP activity was assessed by an enzymatic assay. HSC migration was measured by a wound healing assay and cell invasion was performed using Transwell cell culture chambers. RESULTS: The expression of MMP-2 mRNA and protein in HSC was substantially reduced by EGCG treatment. EGCG treatment also reduced concanavalin A (ConA)-induced activation of secreted MMP-2 and reduced MT1-MMP activity in a dose-dependent manner. In addition, EGCG inhibited either HSC migration or invasion. CONCLUSION: The abilities of EGCG to suppress MMP-2 activation and HSC invasiveness suggest that EGCG may be useful in the treatment and prevention of hepatic fibrosis.