Hanbyoul Cho

Nanog signaling in cancer promotes stem-like phenotype and immune evasion

Adaptation of tumor cells to the host is a major cause of cancer progression, failure of therapy, and ultimately death. Immune selection drives this adaptation in human cancer by enriching tumor cells with a cancer stem cell-like (CSC-like) phenotype that makes them resistant to CTL-mediated apoptosis; however, the mechanisms that mediate CSC maintenance and proliferation are largely unknown. Here, we report that CTL-mediated immune selection drives the evolution of tumor cells toward a CSC-like phenotype and that the CSC-like phenotype arises through the Akt signaling pathway via transcriptional induction of Tcl1a by Nanog. Furthermore, we found that hyperactivation of the Nanog/Tcl1a/Akt signaling axis was conserved across multiple types of human cancer. Inhibition of Nanog in a murine model of colon cancer rendered tumor cells susceptible to immune-mediated clearance and led to successful, long-term control of the disease. Our findings establish a firm link among immune selection, disease progression, and the development of a stem-like tumor phenotype in human cancer and implicate the Nanog/Tcl1a/Akt pathway as a central molecular target in this process.

Lipocalin2 expressions correlate significantly with tumor differentiation in epithelial ovarian cancer.

We recently identified lipocalin2 (LCN2) as being upregulated in ovarian cancer cell lines. The purpose of this study was to validate LCN2 upregulation in ovarian cancers and to investigate its potential as a serum biomarker. We assayed LCN2 expression in ovarian cancers using real-time PCR and IHC. To evaluate the potential of LCN2 as a biomarker, we measured serum LCN2 levels in 54 ovarian cancers, 15 borderline and 53 benign ovarian tumors, and 90 healthy controls. SYBR green PCR and IHC showed LCN2 overexpression in ovarian cancers. LCN2 immunoreactivity was significantly associated with tumor differentiation (p = 0.009), as well-differentiated tumors showed the highest LCN2 expression. Serum LCN2 level in ovarian cancer was significantly higher than in the other study groups (p<0.001), and in accordance with IHC results, it also correlated with tumor differentiation, with well-differentiated tumors having the highest value. The sensitivity and specificity of LCN2 in detecting ovarian cancer was 72.2% and 50.4%, respectively. By Cox univariate analysis, LCN2 positivity was an independent prognostic factor for overall survival (hazard ratio = 1.47, p = 0.012). In conclusion, LCN2 expressions are upregulated and related to tumor differentiation in ovarian cancers and should be included in future research assessing potential biomarkers for ovarian cancer. (J Histochem Cytochem 57:513–521, 2009)

Neutrophil-to-lymphocyte ratio as an adjunct to CA-125 for the diagnosis of endometriosis

OBJECTIVE To investigate the clinical value of differential white blood cell counts and neutrophil-to-lymphocyte ratio (NLR), by themselves or as adjunct to CA-125, in the diagnosis of endometriosis. DESIGN Retrospective study. SETTING University Medical Center. PATIENT(S) Two hundred thirty-one patients with endometriosis, 145 patients with benign ovarian tumors, and 384 healthy controls participated in this study. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Sensitivities and specificities of differential white blood cell (WBC) counts, NLR, serum CA-125, and the combined marker (NLR and serum CA-125) were evaluated by receiver-operating characteristic (ROC) analysis. RESULT(S) The mean NLR and the combined marker in patients with endometriosis were significantly higher than those in patients without endometriosis. The NLR was able to discriminate patients with endometriosis from those with benign ovarian tumors and from healthy controls, and 25 of the 38 endometriosis patients (65.8%) with minimal-to-mild disease exceeded the cutoff value. The combined marker had a sensitivity of 69.3% and specificity of 83.9% with a cutoff value of 55.7, showing 13.5% increase in sensitivity but 8.9% decrease in specificity when compared with serum CA-125 at a cutoff level of 35 IU/mL. The elevated combined marker detected 16 patients with endometriosis (42.1%) with minimal-to-mild disease, whereas only 10 patients (26.3%) had their serum CA-125 levels at more than 35 IU/mL. CONCLUSION(S) Measurement of NLR and the combined marker may be used as simple and easily obtained diagnostic markers for endometriosis.

Membranous expression of Her3 is associated with a decreased survival in head and neck squamous cell carcinoma

BackgroundHead and neck squamous cell carcinoma (HNSCC) still remains a lethal malignancy benefiting from the identification of the new target for early detection and/or development of new therapeutic regimens based on a better understanding of the biological mechanism for treatment. The overexpression of Her2 and Her3 receptors have been identified in various solid tumors, but its prognostic relevance in HNSCC remains controversial.MethodsThree hundred eighty-seven primary HNSCCs, 20 matching metasis and 17 recurrent HNSCCs were arrayed into tissue microarrays. The relationships between Her2 and Her3 protein expression and clinicopathological parameters/survival of HNSCC patients were analyzed with immunohistochemistry.ResultsHer3 is detected as either a cytoplasmic or a membranous dominant expression pattern whereas Her2 expression showed uniform membranous form. In primary tumor tissues, high membranous Her2 expression level was found in 104 (26.9%) cases while positive membranous and cytoplasmic Her3 expression was observed in 34 (8.8%) and 300 (77.5%) samples, respectively. Membranous Her2 expression was significantly associated with histological grade (P = 0.021), as grade 2 tumors showed the highest positive expression. Membranous Her3 over-expression was significantly prevalent in metastatic tissues compared to primary tumors (P = 0.003). Survival analysis indicates that membranous Her3 expression is significantly associated with worse overall survival (P = 0.027) and is an independent prognostic factor in multivariate analysis (hazard ratio, 1.51; 95% confidence interval, 1.01-2.23; P = 0.040).ConclusionsThese results suggest that membranous Her3 expression is strongly associated with poor prognosis of patients with HNSCC and is a potential candidate molecule for targeted therapy.

PI3K/AKT activation induces PTEN ubiquitination and destabilization accelerating tumourigenesis

The activity of the phosphatase and tensin homologue (PTEN) is known to be suppressed via post-translational modification. However, the mechanism and physiological significance by which post-translational modifications lead to PTEN suppression remain unclear. Here we demonstrate that PTEN destabilization is induced by EGFR- or oncogenic PI3K mutation-mediated AKT activation in cervical cancer. EGFR/PI3K/AKT-mediated ubiquitination and degradation of PTEN are dependent on the MKRN1 E3 ligase. These processes require the stabilization of MKRN1 via AKT-mediated phosphorylation. In cervical cancer patients with high levels of pAKT and MKRN1 expression, PTEN protein levels are low and correlate with a low 5-year survival rate. Taken together, our results demonstrate that PI3K/AKT signals enforce positive-feedback regulation by suppressing PTEN function.

Loss of ARID1A/BAF250a expression is linked to tumor progression and adverse prognosis in cervical cancer.

The tumor suppressor gene ARID1A encodes BAF250a, a component of human SWI/SNF chromatin-remodeling complexes. Loss of BAF250a expression has recently been reported in several tumor types. To investigate the potential correlation between BAF250a and various clinicopathologic parameters, we assessed the expression of BAF250a in archival tumor tissue specimens from 147 patients with cervical cancer and 191 with cervical intraepithelial neoplasia as well as 376 matched nonadjacent normal tissues by immunohistochemical staining. Messenger RNA expression level for BAF250a was decreased in cervical cancer cell lines (P = .013) and tissues (P = .010), when compared with normal cervical epithelial tissue using SYBR Green real-time polymerase chain reaction. BAF250a was also detected in nuclear fractions of HeLa cells and in nuclei of cervical cancer tissue samples by Western blotting and immunohistochemistry, respectively. BAF250a expression gradually decreased in transitioning from normal to cervical carcinoma (P < .001), and this loss of expression was significantly associated with tumor stage (P = .005), tumor grade (P = .029), tumor size (P = .003), and lymph node metastasis (P = .020). In multivariate analysis, overall survival in cervical cancer was significantly reduced in cases with BAF250a loss (hazard ratio, 2.78 [1.01-7.63]; P = .047). Our findings suggest a potential role for BAF250a in providing valuable prognostic information to clinicians for risk assessment in cervical cancer.

Overexpression of Glucose Transporter-1 (GLUT-1) Predicts Poor Prognosis in Epithelial Ovarian Cancer

Illumina microarray was used to identify differentially expressed genes in three epithelial ovarian cancer (EOC) cells. To validate the microarray data, mRNA and protein level of glucose transporter-1 (GLUT-1) was examined. GLUT-1 had an EOC/normal cells ratio of 5.51 based on microarray. Real-time PCR and immunohistochemistry demonstrated that GLUT-1 expression was significantly increased in EOC (p = .029 and p < .001, respectively). On survival analysis, GLUT-1 overexpression (HR = 4.80, p = .027) and lymph node metastases (HR = 8.35, p = .016) conferred a significantly worse overall survival. In conclusion, GLUT-1 expression is remarkably upregulated in EOC and predicts a poor overall survival.

Prognostic role and implications of mutation status of tumor suppressor gene ARID1A in cancer: a systematic review and meta-analysis

Loss of the tumor suppressor gene AT-rich interactive domain-containing protein 1A (ARID1A) has been demonstrated in several cancers, but its prognostic role is unknown. We aimed to investigate the risk associated with loss of ARID1A (ARID1A−) for all-cause mortality, cancer-specific mortality and recurrence of disease in subjects with cancer. PubMed and SCOPUS search from database inception until 01/31/2015 without language restriction was conducted, contacting authors for unpublished data. Eligible were prospective studies reporting data on prognostic parameters in subjects with cancer, comparing participants with presence of ARID1A (ARID1A+) vs. ARID1A−, assessed either via immunohistochemistry (loss of expression) or with genetic testing (presence of mutation). Data were summarized using risk ratios (RR) for number of deaths/recurrences and hazard ratios (HR) for time-dependent risk related to ARID1A− adjusted for potential confounders. Of 136 hits, 25 studies with 5,651 participants (28 cohorts; ARID1A−: n = 1,701; ARID1A+: n = 3,950), with a mean follow-up period of 4.7 ± 1.8 years, were meta-analyzed. Compared to ARID1A+, ARID1A− significantly increased cancer-specific mortality (studies = 3; RR = 1.55, 95% confidence interval (CI) = 1.19–2.00, I2 = 31%). Using HRs adjusted for potential confounders, ARID1A− was associated with a greater risk of cancer-specific mortality (studies = 2; HR = 2.55, 95%CI = 1.19–5.45, I2 = 19%) and cancer recurrence (studies = 10; HR = 1.93, 95%CI = 1.22–3.05, I2 = 76%). On the basis of these results, we have demonstrated that loss of ARID1A shortened time to cancer-specific mortality, and to recurrence of cancer when adjusting for potential confounders. For its role, this gene should be considered as an important potential target for personalized medicine in cancer treatment.

Prognostic assessment of hypoxia and metabolic markers in cervical cancer using automated digital image analysis of immunohistochemistry

BackgroundHypoxia inducible factor-1 alpha (HIF-1α), induced by tumor hypoxia, regulates tumor cell metabolism and metastasis by up-regulation of c-Met, carbonic anhydrase 9 (CA9) and glucose transporter 1 (GLUT1). The prognostic significance of hypoxia and metabolic markers is not clearly defined in cervical cancer. Here, we have examined the primary players in the hypoxia signaling pathway, by immunohistochemistry, but confirming their interactions, as well as defining which proteins are associated with outcome.MethodsThe study subjects were comprised of cervical intraepithelial neoplasia (CIN, n = 209), carcinoma in situ (CIS, n = 74), cervical cancer (n = 179), and matched nonadjacent normal tissues (n = 357). Immunohistochemistry (IHC) was performed to identify HIF-1α, c-Met, CA9, and GLUT1. IHC scoring was performed using automated digital image analysis and the association of hypoxic markers with prognostic outcome was evaluated.ResultsHIF-1α, c-Met, CA9 and GLUT1 expression were higher in cervical cancer than in CIN and normal cervix (all P < 0.001). Among these markers, expression of HIF-1α and c-Met were significantly different in FIGO stage (P < 0.001 and P = 0.019, respectively) and patients with lymph node metastasis (P < 0.001 and P = 0.010, respectively). HIF-1α expression was correlated with c-Met expression in cervical cancer (P < 0.001). High expression of HIF-1α and c-Met showed worse 5-year overall survival rate (P = 0.047 and P = 0.005, respectively) than low expression group, but CA9 and GLUT1 did not show significant survival difference. After adjusting the prognostic covariates, c-Met was found to be an independent risk factor (HR=3.27; 95% CI, 1.05-10.23, P = 0.041) for overall survival in cervical cancer.ConclusionsWe demonstrate that c-Met correlates with HIF-1α and is a poor prognostic factor in survival in cervical cancer.

Autoantibodies against stress-induced phosphoprotein-1 as a novel biomarker candidate for ovarian cancer.

Detection of autoantibodies against tumor‐associated antigens (TAA) has recently been shown to be a powerful tool for early detection of various cancers. The aim of this study was to investigate the possibility of using autoantibodies against TAA as novel biomarkers by a proteomics‐based approach in patients with ovarian cancer. We used two‐dimensional differential gel electrophoresis analysis of immuno‐precipitated tumor antigens (2D‐DITA) to compare the levels of autoandibodies in pretreatment and posttreatment sera of patients with ovarian cancers. The identified autoantibodies were validated by SYBR Green real‐time polymerase chain reaction (PCR) and immunohistochemistry (IHC). We further evaluated the level of autoantibody in sera of 68 ovarian cancer patients by an enzyme‐linked immunosorbent assay (ELISA). The autoantibody directed against stress‐induced phosphoprotein‐1 (STIP‐1) emerged as a novel biomarker candidate for ovarian cancer. SYBR Green PCR and IHC confirmed that the STIP‐1 mRNA and protein expression levels were significantly up‐regulated in ovarian cancers compared with normal and benign tumors (P = 0.003 and P < 0.001, respectively). A preliminary ELISA study showed that the serum levels of anti‐STIP‐1 autoantibodies were significantly elevated in ovarian cancer patients compared with healthy controls (P = 0.03). The results suggest that 2D‐DITA is a useful tool to detect autoantibodies and that STIP‐1 is a potential biomarker candidate for ovarian cancers.