The positive impact of cytological specimens for EGFR mutation testing in non-small cell lung cancer:a single South East Asian laboratory's analysis of 670 cases

To compare the rejection rates of non-small cell lung cancer (NSCLC) samples obtained by differing sampling methods for testing by Sanger sequencing for epidermal growth factor receptor (EGFR) mutations. To assess the association between unsatisfactory outcomes and the quantity of DNA extracted from cytological versus histological samples.

RUNX3 downregulation in human lung adenocarcinoma is independent of p53, EGFR or KRAS status

RUNX3 aberrations play a pivotal role in the oncogenesis of breast, gastric, colon, skin and lung tissues. The aim of this study was to characterize further the expression of RUNX3 in lung cancers. To achieve this, a lung cancer tissue microarray (TMA), frozen lung cancer tissues and lung cell lines were examined for RUNX3 expression by immunohistochemistry, while the TMA was also examined for EGFR and p53 expression. RUNX3 promoter methylation status, and EGFR and KRAS mutation status were also investigated. Inactivation of RUNX3 was observed in 70% of the adenocarcinoma samples, and this was associated with promoter hypermethylation but not biased to EGFR/KRAS mutations. Our results suggest a central role of RUNX3 downregulation in pulmonary adenocarcinoma, which may not be dependent of other established cancer-causing pathways and may have important diagnostic and screening implications.

A morpho-molecular prognostic model for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third common cause of cancer-related deaths and its prognostication is still suboptimal. The aim of this study was to establish a new prognostication algorithm for HCC.

JMJD6 is a driver of cellular proliferation and motility and a marker of poor prognosis in breast cancer

We developed an analytic strategy that correlates gene expression and clinical outcomes as a means to identify novel candidate oncogenes operative in breast cancer. This analysis, followed by functional characterization, resulted in the identification of Jumonji Domain Containing 6 (JMJD6) protein as a novel driver of oncogenic properties in breast cancer.

Prolyl isomerase Pin1 downregulates tumor suppressor RUNX3 in breast cancer

Emerging evidence demonstrates that RUNX3 is a tumor suppressor in breast cancer. Inactivation of RUNX3 in mice results in spontaneous mammary gland tumors, and decreased or silenced expression of RUNX3 is frequently found in breast cancer cell lines and human breast cancer samples. However, the underlying mechanism for initiating RUNX3 inactivation in breast cancer remains elusive. Here, we identify prolyl isomerase Pin1, which is often overexpressed in breast cancer, as a key regulator of RUNX3 inactivation. In human breast cancer cell lines and breast cancer samples, expression of Pin1 inversely correlates with the expression of RUNX3. In addition, Pin1 recognizes four phosphorylated Ser/Thr-Pro motifs in RUNX3 via its WW domain. Binding of Pin1 to RUNX3 suppresses the transcriptional activity of RUNX3. Furthermore, Pin1 reduces the cellular levels of RUNX3 in an isomerase activity-dependent manner by inducing the ubiquitination and proteasomal degradation of RUNX3. Knocking down Pin1 enhances the cellular levels and transcriptional activity of RUNX3 by inhibiting the ubiquitination and degradation of RUNX3. Our results identify Pin1 as a new regulator of RUNX3 inactivation in breast cancer.

Coexpressing shRNA with fluorescence tags for quantification of cell migration studies

Understanding migration of cells has many implications in human physiology; some examples include developmental biology, healing, immune responses and tissue remodeling. On the other hand, invasive migration by tumor cells is pathological and is a major cause of mortality amongst cancer sufferers. Cell migration assays have been widely used to quantify potentially metastatic genes. In recent years, the use of RNAi has significantly increased the tools available in cell migration research due to its specific gene targeting for knockdown. The inability to ensure 100% transfection/transduction efficiency reduces the sensitivity of cell migration assays because cells not successfully transfected/transduced with the RNAi are also included in the calculations. This study introduces a different experimental setup mathematically expressed in our named normalized relative infected cell count (N-RICC) that analyses cell migration assays by co-expressing retrovirally transduced shRNA with fluorescence tags from a single vector. Vectors transduced into cells are visible under fluorescence, thus alleviating the problems involved with transduction efficiency by individually identifying cells with targeted genes. Designed shRNAs were targeted against a list of potentially metastatic genes in a highly migratory breast cancer cell line model, MDA-MB-231. We have successfully applied N-RICC analysis to show greater sensitivity of integrin alpha5 (ITGA5) and Ras homologue A (RhoA) in cell metastasis over conventional methods in scratch-wound assays and migration chambers assays.

Proteomic analysis of colorectal cancer metastasis:stathmin-1 revealed as a player in cancer cell migration and prognostic marker

Metastasis accounts largely for the high mortality rate of colorectal cancer (CRC) patients. In this study, we performed comparative proteome analysis of primary CRC cell lines HCT-116 and its metastatic derivative E1 using 2-D DIGE. We identified 74 differentially expressed proteins, many of which function in transcription, translation, angiogenesis signal transduction, or cytoskeletal remodeling pathways, which are indispensable cellular processes involved in the metastatic cascade. Among these proteins, stathmin-1 (STMN1) was found to be highly up-regulated in E1 as compared to HCT-116 and was thus selected for further functional studies. Our results showed that perturbations in STMN1 levels resulted in significant changes in cell migration, invasion, adhesion, and colony formation. We further showed that the differential expression of STMN1 correlated with the cells' metastatic potential in other paradigms of CRC models. Using immunohistochemistry, we also showed that STMN1 was highly expressed in colorectal primary tumors and metastatic tissues as compared to the adjacent normal colorectal tissues. Furthermore, we also showed via tissue microarray analyses of 324 CRC tissues and Kaplan-Meier survival plot that CRC patients with higher expression of STMN1 have poorer prognosis.

Clinical and therapeutic relevance of PIM1 kinase in gastric cancer

Gastric cancer is a leading cause of cancer-related mortality, and chemotherapeutic options are currently limited. PIM1 kinase, an oncogene that promotes tumorigenesis in several cancer types, might represent a novel therapeutic target in gastric cancer.

Dual-colour HER2/chromosome 17 chromogenic in situ hybridisation enables accurate assessment of HER2 genomic status in ovarian tumours

Ovarian cancer is a leading cause of gynaecological cancer-related morbidity and mortality. There has been increasing interest in the potential utility of anti-human epidermal growth factor receptor 2 (anti-HER2) agents in the treatment of this disease, with the attendant need to identify suitable predictive biomarkers of response to treatment.

Clinical and testing protocols for the analysis of epidermal growth factor receptor mutations in East Asian patients with non-small cell lung cancer:a combined clinical-molecular pathological approach

Several randomized phase III studies in advanced stage non-small cell lung cancer (NSCLC) confirmed the superior response rate and progression-free survival of using epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor as first-line therapy compared with chemotherapy in patients with activating EGFR mutations. Despite the need for EGFR mutation tests to guide first-line therapy in East Asian NSCLC, there are no current standard clinical and testing protocols.

Sequential expression of putative stem cell markers in gastric carcinogenesis

Gastric carcinogenesis has been well documented in the step-wise histopathological model, known as Correa pathway. Several biomarkers including CD44, Musashi-1 and CD133 have been reported as putative stem cell (PSC) markers.

Elevated NRD1 metalloprotease expression plays a role in breast cancer growth and proliferation

Understanding the molecular etiology of cancer and increasing the number of drugs and their targets are critical to cancer management. In our attempt to unravel novel breast-cancer associated proteins, we previously conducted protein expression profiling of the MCF10AT model, which comprises a series of isogenic cell lines that mimic different stages of breast cancer progression. NRD1 expression was found to increase during breast cancer progression. Here, we attempted to confirm the relevance of NRD1 in clinical breast cancer and understand the functional role and mechanism of NRD1 in breast cancer cells. Immunohistochemistry data show that NRD1 expression was elevated in ductal carcinoma in situ and invasive ductal carcinomas compared with normal tissues in 30% of the 26 matched cases studied. Examination of NRD1 expression in tissue microarray comprising >100 carcinomas and subsequent correlation with clinical data revealed that NRD1 expression was significantly associated with tumor size, grade, and nodal status (P <0.05). Silencing of NRD1 reduced MCF10CA1h and MDA-MD-231 breast-cancer-cell proliferation and growth. Probing the oncogenic EGF signaling pathways revealed that NRD1 knock down did not affect overall downstream tyrosine phosphorylation cascades including AKT and MAPK activation. Instead, silencing of NRD1 resulted in a reduction of overall cyclin D1 expression, a reduction of EGF-induced increase in cyclin D1 expression and an increase in apoptotic cell population compared with control cells.