Association of gankyrin and stemness factor expression in human colorectal cancer

Gankyrin activates the hedgehog signalling to drive metastasis in osteosarcoma

Gankyrin is a regulatory subunit of the 26-kD proteasome complex and promotes the occurrence and progression of many malignancies. However, the role of gankyrin in osteosarcoma (OS) metastasis remains unclear. Hedgehog signalling has been shown to regulate stem cell homeostasis and cancer metastasis, but the mechanisms that activate this pathway in OS are still poorly understood. Here, a series of in vitro and in vivo assays were carried out to explore the function and mechanism of gankyrin regulating Hedgehog signalling in OS. We demonstrated that gankyrin promotes migration, invasion and regulates the expression of some stemness factors by up-regulating Gli1 in OS. Importantly, our data showed an interaction between gankyrin and Gli1. Moreover, gankyrin suppresses the ubiquitin-mediated degradation of Gli1 protein in OS. Gankyrin also significantly promotes the lung metastasis of OS in vivo. Our findings suggest that gankyrin drives metastasis and regulates the expression of some stemness factors in osteosarcoma by activating Hedgehog signalling, indicating that drug screening for compounds targeting gankyrin may contribute to the development of novel and effective therapies for OS.

Deficiency of Gankyrin in the small intestine is associated with augmented colitis accompanied by altered bacterial composition of intestinal microbiota

Background

Gankyrin (GK) is an oncoprotein which regulates inflammatory responses and its inhibition is considered as a possible anti-inflammatory therapy for inflammatory bowel disease (IBD).

Methods

In this study, we investigated the role of GK in epithelial cells using mice with intestinal epithelial cell-specific GK deletion in (i) the entire small intestine and colon (Villin-Cre;Gankyrin^f/f) and (ii) the distal intestine and colon (Cdx2-Cre;Gankyrin^f/f).

Result

Unexpectedly, GK-deficiency in the upper small bowel augmented inflammatory activity compared with control mice when colitis was induced with dextran sodium sulfate. Biochemical analyses have revealed GK-deficiency to have caused reduction in the expression of antimicrobial peptides, α-Defensin-5 and -6, in the upper small bowel. Examination of human samples have further confirmed that the reduction of GK expression in the small bowel is associated with colonic involvement in human Crohn’s disease. Through the sequencing of bacterial 16S rRNA gene amplicons, bacteria potentially deleterious to intestinal homeostasis such as Helicobacter japonicum and Bilophila were found to be over-represented in colitis induced Villin-Cre;Gankyrin^f/f mice when compared to Gankyrin^f/f control mice under the same condition.

Conclusion

These results highlight the distinct site dependence of the pro- and anti-inflammatory functions of GK and provide important insights into the pathogenesis of IBD.

p28GANK overexpression is associated with chemotherapy resistance and poor prognosis in ovarian cancer

The non-ATPase regulatory subunit 10 of the human 26S proteasome (p28GANK) has been implicated in the tumorigenesis and progression of several types of malignant tumor. The aim of the present study was to detect the expression of p28GANK in ovarian cancer (OC) and investigate its association with the clinicopathological features and prognosis of OC. The expression levels of p28GANK were determined in 114 OC tissue samples and 30 normal ovarian tissue samples using immunohistochemistry. An association was observed between p28GANK overexpression and certain clinicopathological factors, including advanced International Federation of Gynecology and Obstetrics stage (P=0.042), residual tumor size (P=0.005) and response to chemotherapy (P<0.001). Furthermore, patients with high expression of p28GANK demonstrated worse overall survival (OS) and disease-free survival (DFS) rates compared with patients with low expression of p28GANK (both P<0.001). Multivariate Cox regression analysis revealed that overexpression of p28GANK was an independent prognostic factor of OS and DFS in patients with OC (P=0.013 and P=0.001, respectively). In summary, the current results indicate that p28GANK may be a predictive marker and a therapeutic target for OC.

Increased Expression of Gankyrin and Stemness Factor Oct-4 are Associated with Unfavorable Clinical Outcomes and Poor Benefit of Tamoxifen in Breast Carcinoma Patients

Tamoxifen is the most important treatment component in estrogen receptor positive (ER+) breast carcinoma patients. Tamoxifen resistance incidence presents an important obstacle in clinical treatment. Mechanisms underlying tamoxifen refractory are not completely understood. Although elevated expression of Gankyrin (P28GANK) and stem cell markers Nanog, Oct-4 and Sox-2 have been reported in breast carcinoma, their role in tamoxifen resistance progression has not been explored. In the present study, P28GANK and stem cell markers Nanog, Oct-4 and Sox-2 expression were evaluated using quantitative RT-PCR and immunohistochemical technology in 72 breast carcinoma patients who received tamoxifen as adjuvant anti-hormone treatment. Expression data were correlated with the clinical outcome and survival of patients. Data analysis showed that P28GANK, Oct-4 and Sox-2 transcripts were significantly overexpressed in tamoxifen resistance patients. Immunohistochemical staining indicated that protein expression of P28GANK and Oct-4 were also significantly higher in tamoxifen resistance patients. We have shown a positive correlation between mRNA and protein expression of P28GANK, Oct-4 and Sox-2. Multivariate logistic regression analysis indicated that P28GANK (P = 0.002) and Oct-4 (P = 0.013) overexpression could be negative independent factors of disease outcome. Additionally, in the whole study group, multivariate Cox regression analysis revealed that high expression of P28GANK and Oct-4 remained significant and unfavorable predictive factors for patients' survival. These findings suggest that Gankyrin and Oct-4 overexpression could promote tamoxifen refractory in breast cancer patients. More studies are warranted to clarify the predictive role of these potential biomarkers for patients who don't benefit from tamoxifen treatment and their possible application as prognostic markers in ER⁺ tamoxifen-treated breast carcinoma patients.

Gankyrin drives metabolic reprogramming to promote tumorigenesis, metastasis and drug resistance through activating β-catenin/c-Myc signaling in human hepatocellular carcinoma

Gankyrin plays important roles in tumorigenicity and metastasis of hepatocellular carcinoma (HCC). We have for the first time investigated the effects of Gankyrin on glycolysis and glutaminolysis both in vitro and in vivo, including in patient-derived xenografts. We reported Gankyrin increases glucose consumption, lactate production, glutamine consumption and glutamate production in HCC through upregulating the expression of the transporters and enzymes involved in glycolysis and glutaminolysis, including HK2, GLUT1, LDHA, PKM2, ASCT2 and GLS1. We further demonstrated that Gankyrin drives glycolysis and glutaminolysis through upregulating c-Myc via activating β-catenin signaling. Importantly, we found c-Myc mediated metabolic reprogramming might contribute to the tumorigenicity, metastasis and drug resistance induced by Gankyrin. c-Myc inhibitor synergizes with Sorafenib or Regorafenib to suppress HCC PDX tumors with high Gankyrin levels. We detected a significant correlation between Gankyrin and β-catenin expression levels in a cohort of HCC biopsies, and combination of these two parameters is a more powerful predictor of poor prognosis. Collectively, our results uncovered that Gankyrin functions as an essential regulator in glycolysis and glutaminolysis via activation of β-catenin/c-Myc to promotes tumorigenesis, metastasis and drug resistance in human HCC.

The oncoprotein gankyrin promotes the development of colitis-associated cancer through activation of STAT3

Although long-standing colonic inflammation due to refractory inflammatory bowel disease (IBD) promotes the development of colitis-associated cancer (CAC), the molecular mechanisms accounting for the development of CAC remains largely unknown. In this study, we investigated the role of gankyrin in the development of CAC since gankyrin is overexpressed in sporadic colorectal cancers. We analyzed gene expression of colon tissues obtained from 344 patients with IBD and CAC and found that expression of gankyrin was much higher in colonic mucosa of patients with refractory IBD than in those with IBD in remission. Expression of gankyrin was upregulated in inflammatory cells as well as tumor cells in colonic mucosa of patients with CAC. Over-expressing studies utilizing tagged ganlyrin-cDNA identified physical interaction between ganlyrin and Src homology 2-containing protein tyrosine phosphatase-1 (SHP-1). Importantly, the interaction between ganlyrin and SHP-1 leads to inhibition of STAT3 activation and to enhancement of TNF-α and IL-17 in inflammatory cells. To further address the role of gankyrin in the development of CAC, we created mice with intestinal epithelial cell-specific gankyrin ablation (Vil-Cre;Gankyrin^f/f) and deletion of gankyrin in myeloid and epithelial cells (Mx1-Cre;Gankyrin^f/f). Gankyrin deficiency in myeloid cells, but not in epithelial cells, reduced the activity of mitogen activated protein kinase and the expression of stem cell markers, leading to attenuated tumorigenic potential. These findings provide important insights into the pathogenesis of CAC and suggest that gankyrin is a promising target for developing therapeutic and preventive strategies against CAC.

Gankyrin induces STAT3 activation in tumor microenvironment and sorafenib resistance in hepatocellular carcinoma

Most hepatocellular carcinomas (HCC) develop as a result of chronic liver inflammation. We have shown that the oncoprotein gankyrin is critical for inflammation‐induced tumorigenesis in the colon. Although the in vitro function of gankyrin is well known, its role in vivo remains to be elucidated. We investigated the effect of gankyrin in the tumor microenvironment of mice with liver parenchymal cell‐specific gankyrin ablation (Alb‐Cre;gankyrin^f/f) and gankyrin deletion both in liver parenchymal and non‐parenchymal cells (Mx1‐Cre;gankyrin^f/f). Gankyrin upregulates vascular endothelial growth factor expression in tumor cells. Gankyrin binds to Src homology 2 domain‐containing protein tyrosine phosphatase‐1 (SHP‐1), mainly expressed in liver non‐parenchymal cells, resulting in phosphorylation and activation of signal transducer and activator of transcription 3 (STAT3). Gankyrin deficiency in non‐parenchymal cells, but not in parenchymal cells, reduced STAT3 activity, interleukin (IL)‐6 production, and cancer stem cell marker (Bmi1 and epithelial cell adhesion molecule [EpCAM]) expression, leading to attenuated tumorigenic potential. Chronic inflammation enhances gankyrin expression in the human liver. Gankyrin expression in the tumor microenvironment is negatively correlated with progression‐free survival in patients undergoing sorafenib treatment for HCC. Thus, gankyrin appears to play a critical oncogenic function in tumor microenvironment and may be a potential target for developing therapeutic and preventive strategies against HCC.

TGF-β1 signaling pathway serves a role in HepG2 cell regulation by affecting the protein expression of PCNA, gankyrin, p115, XIAP and survivin

The transforming growth factor-β (TGF-β) signaling pathway serves a key role in the pathogenesis of liver cancer. To investigate the association between TGF-β1 and the following proteins: Proliferating cell nuclear antigen (PCNA), gankyrin, general vesicular transport factor p115 (p115), X-linked inhibitor of apoptosis protein (XIAP) and survivin, HepG2 liver cancer cells were transfected with small interfering RNA (siRNA) directed against TGF-β1, or were treated with exogenous TGF-β1. TGF-β1 protein expression levels were assessed at 72 and 96 h using western blotting, cell growth was evaluated using a Cell Counting kit-8 assay, and flow cytometry was used to examine cell cycle distribution and apoptosis. In addition, PCNA, gankyrin, p115, XIAP and survivin protein levels were evaluated using western blotting. TGF-β1 protein expression levels were decreased at 72 and 96 h following siRNA transfection, indicating that the siRNA against TGF-β1 was effective. In the TGF-β1-knockdown group, the HepG2 cells exhibited G₁ or S-phase cell cycle arrest; therefore, the number of G₂-phase cells was decreased, cell growth was inhibited and apoptotic peaks were observed. By contrast, no significant alteration in cell cycle distribution or apoptosis was observed in the cells treated with exogenous TGF-β1. In the exogenous TGF-β1 group, PCNA and XIAP protein expression levels were increased, whereas gankyrin, p115 and survivin protein expression was observed to be dependent on the duration of treatment. By contrast, PCNA, gankyrin, XIAP and survivin protein expression decreased following TGF-β1 knockdown; however, p115 protein expression increased. In conclusion, the TGF-β1 signaling pathway may affect cell growth, cell cycle distribution and apoptosis through the regulation of PCNA, gankyrin, p115, XIAP and survivin protein expression in liver cancer. The results of the present study may improve the current understanding of the role of the TGF-β signaling pathway during the pathogenesis of liver cancer.

MicroRNA-1254 inhibits the migration of colon adenocarcinoma cells by targeting PSMD10

OBJECTIVE

MicroRNA-1254 (miR-1254) has not been studied in colorectal cancer (CRC) to date. This study aimed to investigate the inhibitory mechanism of miR-1254 in CRC tumorigenesis.

METHODS

MiR-1254 expression was examined using real-time polymerase chain reaction in CRC and adjacent non-tumorous tissues. The correlation between miR-1254 expressions and proliferation and migration of cancer cells was determined using the CCK-8 and transwell assays. RNA sequencing was used to identify differentially expressed genes downstream from miR-1254. A luciferase reporter assay was used to confirm the direct interaction between miR-1254 and its predicted target gene, PSMD10. Moreover, PSMD10 was either overexpressed or silenced in colon carcinoma cells overexpressing miR-1254 to determine whether their interaction contributed to CRC migration and epithelial-mesenchymal transition (EMT).

RESULTS

Significantly lower miR-1254 expressions were observed in CRC tissues than in adjacent non-tumorous tissues. Exogenous miR-1254 expression suppressed the migration of colon carcinoma cell lines SW1116 and HCT116. RNA sequencing and luciferase assays revealed that miR-1254 directly binded to the 3'-untranslated region of PSMD10, an important regulator of EMT and cell migration. PSMD10 knockdown inhibited EMT and colon cancer cell migration, whereas PSMD10 overexpression reversed the inhibition of EMT and cell migration caused by miR-1254.

CONCLUSION

MiR-1254 may act as a tumor suppressor in CRC and may inhibit CRC migration by directly targeting PSMD10 to suppress the EMT process.

Proteasome expression and activity in cancer and cancer stem cells

Proteasome is a multi-protein organelle that participates in cellular proteostasis by destroying damaged or short-lived proteins in an organized manner guided by the ubiquitination signal. By being in a central place in the cellular protein complement homeostasis, proteasome is involved in virtually all cell processes including decisions on cell survival or death, cell cycle, and differentiation. These processes are important also in cancer, and thus, the proteasome is an important regulator of carcinogenesis. Cancers include a variety of cells which, according to the cancer stem cell theory, descend from a small percentage of cancer stem cells, alternatively termed tumor-initiating cells. These cells constitute the subsets that have the ability to propagate the whole variety of cancer and repopulate tumors after cytostatic therapies. Proteasome plays a role in cellular processes in cancer stem cells, but it has been found to have a decreased function in them compared to the rest of cancer cells. This article will discuss the transcriptional regulation of proteasome sub-unit proteins in cancer and in particular cancer stem cells and the relationship of the proteasome with the pluripotency that is the defining characteristic of stem cells. Therapeutic opportunities that present from the understanding of the proteasome role will also be discussed.

Apoptotic pathways and stemness in the colorectal epithelium and lamina propria mucosae during the human embryogenesis and carcinogenesis

AIM

Programmed cell death is essential both during normal organ development and carcinogenesis. In this study we immunohistochemically analyzed different pathways of cell death in 11 human conceptuses 5th-10th-weeks old, 10 low and high grade colorectal carcinomas (CRC), and 10 normal colon samples by using markers for apoptosis (caspase-3, AIF, TUNEL), proliferation (Ki-67) and stemness (Oct-4).

RESULTS

Between the 5th and 10th week of development, caspase-3 and AIF showed moderate-to-strong expression in the developing gut wall. During development, number of caspase-3-reactive cells decreased, while AIF increased. While healthy colorectal control and low grade CRC showed moderate expression of caspase-3 and AIF, in high grade CRC their expression was strong. Tumor tissues displayed significantly higher number of positive cells than controls. Occasionally, co-expressing of both markers characterized dying cells. In developing colon, Oct-4 and Ki-67 showed moderate-to-strong expression, while some cells co-expressed both markers. Their number decreased in the epithelium and increased in the connective tissue in later development. Healthy colorectal control displayed moderate Ki-67 and mild Oct-4 reactivity. While in low-grade CRC expression Oct-4 and Ki-67 was moderate, in high-grade CRC their expression was strong. Although Oct-4 and TUNEL occasionally co-expressed in all samples, both grades of CRC contained cells that were Oct-4 positive only.

CONCLUSION

Our study revealed two different parallel pathways of cell death, with characteristic increase of AIF-mediated apoptosis when compared to caspase-3, and presence of stemness cells both during colon development and carcinogenesis. These finding might be considered as important diagnostic, survival and CRC therapy predictors.

Role of the RB-Interacting Proteins in Stem Cell Biology

Human retinoblastoma gene RB1 is the first tumor suppressor gene (TSG) isolated by positional cloning in 1986. RB is extensively studied for its ability to regulate cell cycle by binding to E2F1 and inhibiting the transcriptional activity of the latter. In human embryonic stem cells (ESCs), only a minute trace of RB is found in complex with E2F1. Increased activity of RB triggers differentiation, cell cycle arrest, and cell death. On the other hand, inactivation of the entire RB family (RB1, RBL1, and RBL2) in human ESC induces G2/M arrest and cell death. These observations indicate that both loss and overactivity of RB could be lethal for the stemness of cells. A question arises why inactive RB is required for the survival and stemness of cells? To shed some light on this question, we analyzed the RB-binding proteins. In this review we have focused on 27 RB-binding partners that may have potential roles in different aspects of stem cell biology.

Overexpression of p28GANK accelerates the metastasis of oesophageal squamous cell carcinoma

The present study aimed to evaluate the effects of p28GANK expression on the metastasis of oesophageal squamous cell carcinoma (ESCC) tissues and to investigate its roles in the metastasis of highly invasive and non‑invasive ESCC cell lines. Quantitative polymerase chain reaction (qPCR) and immunohistochemical analyses were performed to assess p28GANK mRNA and protein expression in ESCC tissues and to analyse its significance in ESCC metastasis. qPCR and western blot analyses were used to detect p28GANK mRNA and protein expression in highly invasive and non‑invasive cell lines. Subsequently, lentivirus‑mediated p28GANK short interfering RNA (siRNA) was transfected into highly invasive ESCC cells, and Transwell assays were performed to analyse the effects of p28GANK knockdown on their migration and invasion. The mean expression levels of p28GANK mRNA in the ESCC tissues of patients with metastasis were significantly higher than those in the ESCC specimens from patients without metastasis. p28GANK expression in ESCC tissues was correlated with T‑stage, lymph node metastasis and lymphatic invasion. The mRNA and protein expression levels of p28GANK were significantly higher in highly invasive cell lines compared with those of matched, non‑invasive cell lines. Lentivirus‑mediated siRNA knockdown of p28GANK markedly decreased p28GANK expression in EC109‑P and EC9706‑P cells and supressed the metastasis of ESCC cells in vitro. In conclusion, p28GANK expression was increased in metastatic ESCC tissues and cells, and p28GANK knockdown decreased the metastatic ability of ESCC cells. These results suggested that p28GANK may be a potential therapeutic marker for ESCC metastasis.

Involvement of heat shock protein a4/apg-2 in refractory inflammatory bowel disease

BACKGROUND

Expression of heat shock protein A4 (HSPA4, also called Apg-2), a member of the HSP110 family, is induced by several forms of stress. The physiological and pathological functions of HSPA4 in the intestine remain to be elucidated.

METHODS

We assessed HSPA4 expression and function by generating HSPA4-deficient mice and using 214 human intestinal mucosa samples from patients with inflammatory bowel disease (IBD).

RESULTS

In the colonic mucosa of patients with IBD, a significant correlation was observed between the expression of HSPA4 and antiapoptotic protein Bcl-2, a T-cell-derived cytokine IL-17 or stem cell markers, such as Sox2. In refractory ulcerative colitis, a condition associated with increased cancer risk, expression of HSPA4 and Bcl-2 was increased in inflammatory cells of colonic mucosae. HSPA4 was overexpressed both in cancer cells and immune cells of human colorectal cancers. Patients with high expression of HSPA4 or Bmi1 showed significantly lower response rates upon subsequent steroid therapy as compared with patients with low expression of each gene. HSPA4-deficient mice exhibit more apoptosis and less expression of IL-17/IL-23 in inflammatory cells and less number of Sox2 cells after administration of dextran sodium sulfate than control mice. Transduction of HspaA4 bone marrow into wild-type mice reduced the immune response.

CONCLUSIONS

Upregulation of Bcl-2 and IL-17 by HSPA4 would control apoptosis of inflammatory cells and immune response in the gut, which might develop treatment resistance in IBD. HSPA4 and Bmi1 would be a useful biomarker for refractory clinical course and a promising approach for a therapeutic strategy in patients with IBD.

OCT-4 and DAZL expression in precancerous lesions of the human uterine cervix

AIM

To determine whether octamer-binding transcription factor 4 (OCT-4) and deleted in azoospermia like (DAZL) are expressed among cells with human papilloma virus (HPV) infection and cervical intraepithelial neoplasia (CIN) lesions and quantify their relative expression when compared with normal cervical cultures.

METHODS

Cervical cells derived from normal cell cultures, HPV lesions and CIN lesions were cultured in Dulbecco's modified Eagle's medium supplemented with 20% amniotic fluid and 5 ng/mL basic fibroblast growth factor at 37°C and humidified 10% CO2 in air. Real-time polymerase chain reaction (PCR) was carried out using G6PD as a reference. We used REST for statistical analysis of real-time PCR.

RESULTS

Whereas DAZL was not expressed either in normal cultures or HPV and CIN lesions, OCT-4 was expressed in all examined cell lines. Moreover its relative expression was significantly upregulated among cultures of HPV-infected cells (RE, 11.003; 95%CI: 0.054-36 704.527, P = 0.042), an observation that was also close to statistical significance among cultures of CIN lesions (P = 0.066).

CONCLUSION

The relative expression of OCT-4 is upregulated during the early, preinvasive stages of cervical carcinogenesis. Future studies should investigate its potential as a screening marker and as a possible target of therapy.

MiR-605 represses PSMD10/Gankyrin and inhibits intrahepatic cholangiocarcinoma cell progression

The aberrant expression of PSMD10 has important functions in various malignancies. This study showed that PSMD10 was highly expressed and inversely correlated with the expression of miR-605 in intrahepatic cholangiocarcinoma (ICC) specimens. MiR-605 directly targeted and repressed PSMD10 expression. In addition, over-expression of miR-605 inhibited ICC cell progression both in vitro and in vivo. This effect of miR-605 on ICC cells was similar to that of PSMD10 knock-down by RNAi. Moreover, restoration of PSMD10 could reverse the phenotypic alteration caused by miR-605 in ICC cells. These results suggest a new therapeutic strategy in ICC by restoring miR-605, which is regulated by p53.

Expression of cancer stem cell marker during 4-nitroquinoline 1-oxide-induced rat tongue carcinogenesis

One of the theories regarding oral carcinogenesis is that the tumor growth is initiated from cancer stem cells (CSCs) that self-renew and give rise to differentiated tumor cells, like stem cells do in normal tissues. The most common methods of CSC identification are based on CSC marker expression in carcinogenesis. This study examined the expression of CD133 and CD44, the most commonly used CSC biomarkers in oral squamous cell sarcoma (SCC), with the goal of identifying molecular biomarkers whose expression is associated with the multistep oral carcinogenesis. The expression of CD133, CD44, proliferating cell nuclear antigen (PCNA), and Cytokeratin (CK) was examined by Western blot analysis and confirmed by immunohistochemistry in a 4-nitroquinoline 1-oxide-induced rat tongue carcinogenesis model. Also, the expression of aldehyde dehydrogenase 1 (ALDH1), OCT-4 and Nanog were investigated for alteration of cancer cell stemness by Western blot. Along with the progress of multistep carcinogenesis, there were slight increases of CD133 and CD44 expression in the dysplasia group compared with normal rats. However, CD133 protein level was significantly overexpressed in SCC. The expression of PCNA and CK were low in normal group, but sequentially increased in SCC. ALDH1, Nanog and OCT-4 expression were significantly increased according to SCC grade during carcinogenesis. The findings indicate that CD133 is useful in identifying oral CSCs, which suggests that CD133 may serve as a predictor to identify CSCs with a high risk of oral cancer development.

Gankyrin promotes tumor growth and metastasis through activation of IL-6/STAT3 signaling in human cholangiocarcinoma

Although gankyrin is involved in the tumorigenicity and metastasis of some malignancies, the role of gankyrin in cholangiocarcinoma (CCA) is unclear. In this study we investigated the expression of gankyrin in human CCA tissues and cell lines. The effects of gankyrin on CCA tumor growth and metastasis were determined both in vivo and in vitro. The results showed that gankyrin was overexpressed in CCA tissues and cell lines. Gankyrin expression was associated with CCA histological differentiation, TNM stage, and metastasis. The multivariate Cox analysis revealed that gankyrin was an independent prognostic indicator for overall survival. Gankyrin overexpression promoted CCA cell proliferation, migration, and invasion, while gankyrin knockdown inhibited CCA tumor growth, metastasis, and induced Rb-dependent senescence and G1 phase cell cycle arrest. Gankyrin increased the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and promoted the nuclear translocation of p-STAT3. Suppression of STAT3 signaling by small interfering RNA (siRNA) or STAT3 inhibitor interfered with gankyrin-mediated carcinogenesis and metastasis, while interleukin (IL)-6, a known upstream activator of STAT3, could restore the proliferation and migration of gankyrin-silenced CCA cells. The IL-6 level was decreased by gankyrin knockdown, while increased by gankyrin overexpression. Gankyrin regulated IL-6 expression by way of facilitating the phosphorylation of Rb; meanwhile, rIL-6 treatment increased the expression of gankyrin, suggesting that IL-6 was regulated by a positive feedback loop involving gankyrin in CCA. In the xenograft experiments, gankyrin overexpression accelerated tumor formation and increased tumor weight, whereas gankyrin knockdown showed the opposite effects. The in vivo spontaneous metastasis assay revealed that gankyrin promoted CCA metastasis through IL-6/STAT3 signaling pathway.

CONCLUSION

Gankyrin is crucial for CCA carcinogenesis and metastasis by activating IL-6/STAT3 signaling pathway through down-regulating Rb protein.

Apoptotic pathways in ovarian surface epithelium of human embryos during embryogenesis and carcinogenesis: close relationship of developmental plasticity and neoplasm

Cell differentiation and different pathways of cell death were immunohistochemically analyzed in ovaries of six human embryos, 20 serous borderline tumors (SBT) and ovarian serous carcinomas (OSC) using markers for apoptosis (caspase-3, AIF, TUNEL) and stemness (Oct-4). In the 5-8-week ovaries, caspase-3 was absent in the ovarian surface epithelium (ose) and mildly positive in the ovarian stroma (os), AIF was expressed moderately, while Oct-4 expression gradually decreased during that period. Some ovarian cells expressed only caspase-3 or AIF together with TUNEL, while both caspase-3 and AIF were co-expressed in other ovarian cells. Mild expression of Oct-4 and caspase-3 characterized some cells of SBT, while their expression varied from mild to strong in OSC. AIF displayed mild to strong expression in ose of SBT and moderate to strong expression in OSC, while no expression of AIF was observed in os of both tumors. In the ose of both SBT and OSC, caspase-3 and AIF were co-expressed only occasionally, while AIF and Oct-4 were co-expressed strongly. Our study showed the presence of stemness cells and different pathways of cell death (caspase-3 and AIF-mediated) in the ovarian tissue during development and carcinogenesis, indicating the correlation between developmental plasticity in human embryonic ovaries and OSC.

Molecular biomarkers of cancer stem/progenitor cells associated with progression, metastases, and treatment resistance of aggressive cancers

The validation of novel diagnostic, prognostic, and predictive biomarkers and therapeutic targets in tumor cells is of critical importance for optimizing the choice and efficacy of personalized therapies. Importantly, recent advances have led to the identification of gene-expression signatures in cancer cells, including cancer stem/progenitor cells, in the primary tumors, exosomes, circulating tumor cells (CTC), and disseminated cancer cells at distant metastatic sites. The gene-expression signatures may help to improve the accuracy of diagnosis and predict the therapeutic responses and overall survival of patients with cancer. Potential biomarkers in cancer cells include stem cell-like markers [CD133, aldehyde dehydrogenase (ALDH), CD44, and CD24], growth factors, and their cognate receptors [epidermal growth factor receptor (EGFR), EGFRvIII, and HER2], molecules associated with epithelial-mesenchymal transition (EMT; vimentin, N-cadherin, snail, twist, and Zeb1), regulators of altered metabolism (phosphatidylinositol-3' kinase/Akt/mTOR), and drug resistance (multidrug transporters and macrophage inhibitory cytokine-1). Moreover, different pluripotency-associated transcription factors (Oct3/4, Nanog, Sox2, and Myc) and microRNAs that are involved in the epigenetic reprogramming and acquisition of stem cell-like properties by cancer cells during cancer progression may also be exploited as molecular biomarkers to predict the risk of metastases, systemic treatment resistance, and disease relapse of patients with cancer.

Hypothermia protects against fulminant hepatitis in mice by reducing reactive oxygen species production

OBJECTIVE

Mild hypothermia (32-33°C) shows protective effects in patients with brain damage and cardiac arrest. Although cold-inducible RNA-binding protein (CIRP) contributes to the protective effects of hypothermia through extracellular signal-regulated kinase activation in fibroblasts, the effects of hypothermia in the liver remain unclear.

METHODS

We analysed the effects of cold temperature on fulminant hepatitis, a potentially fatal disease, using the D-galactosamine (GalN)/lipopolysaccharide (LPS) and concanavalin (con) A-induced hepatitis models in mice. After GalN/LPS administration and anaesthesia, mice in the hypothermia group were kept at 25°C and those in control group were kept at 35°C. After concanavalin A (con A) administration, the mice in the hypothermia group were placed in a chamber with an ambient temperature of 6°C for 1.5 h.

RESULTS

Hypothermia attenuated liver injury and prolonged survival. Activation of c-Jun N-terminal kinase and Akt, which are involved in reactive oxygen species (ROS) accumulation, was suppressed by low temperature. Hypothermia significantly decreased oxidized protein levels, and treatment with N-acetyl-L-cysteine, an antioxidant, attenuated GalN/LPS-induced liver injury. In con A-induced hepatitis, CIRP expression was upregulated and Bid expression was downregulated, resulting in decreased apoptosis of hepatocytes in the hypothermia group.

CONCLUSIONS

These data suggest that hypothermia directly protects hepatocytes from cell death via reduction of ROS production in fulminant hepatitis.