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Background: Some sporadic colon cancers and hereditary nonpolyposis colorectal cancer (HNPCC) have been known by a constitutional defect in mismatch gene repair (MMR) and dysfunction in of this MMR system, which lead to an aberrant phenotype that can cause microsatellite instability. However, the clinicopathologic features of still existing microsatellite stable (MSS) colon cancer remain to be investigated. Method: We compared the gene expression patterns of nine tumor tissues of HNPCC and nine tumor tissues of sporadic colon cancer with their adjacent pathologically normal, MSS tissues by modified differential display-polymerase chain reaction, selected four potential marker genes, and confirmed their reproducibility by reverse transcriptase-polymerase chain reaction. Results: Reg I, MLCK, and MYH11 in tumors of MSS HNPCC showed significant differences in gene expression pattern compared with the adjacent pathologically normal tissues (P = 0.028, P = 0.002, and P = 0.001, respectively). Similar differences in expression patterns for the same set of genes were seen between the sporadic colon cancer group and their adjacent pathologically normal tissues (P = 0.012, P = 0.003, and P = 0.002, respectively). Conclusion: We suggest that the three cancer-associated differentially expressed genes in MSS sporadic colon cancer or MSS HNPCC might be potential tumor markers. [Copyright &y& Elsevier]

Purpose: Recently, we developed allele-discriminating priming system (ADPS) technology. This method increases the sensitivity of conventional quantitative polymerase chain reaction up to 100 folds, with limit of detection, 0.01%, with reinforced specificity. This prospective study aimed to develop and validate the accuracy of ADPS epidermal growth factor receptor (EGFR) Mutation Test Kit using clinical specimens., Materials and Methods: In total 189 formalin-fixed paraffin-embedded tumor tissues resected from patients with non-small cell lung cancer were used to perform a comparative evaluation of the ADPS EGFR Mutation Test Kit versus the cobas EGFR Mutation Test v2, which is the current gold standard. When the two methods had inconsistent results, next-generation sequencing-based CancerSCAN was utilized as a referee., Results: The overall agreement of the two methods was 97.4% (93.9%-99.1%); the positive percent agreement, 95.0% (88.7%-98.4%); and the negative percent agreement, 100.0% (95.9%-100.0%). EGFR mutations were detected at a frequency of 50.3% using the ADPS EGFR Mutation Test Kit and 52.9% using the cobas EGFR Mutation Test v2. There were 10 discrepant mutation calls between the two methods. CancerSCAN reproduced eight ADPS results. In two cases, mutant allele fraction was ultra-low at 0.02% and 0.06%, which are significantly below the limit of detection of the cobas assay and CancerSCAN. Based on the EGFR genotyping by ADPS, the treatment options could be switched in five patients., Conclusion: The highly sensitive and specific ADPS EGFR Mutation Test Kit would be useful in detecting the patients who have lung cancer with EGFR mutation, and can benefit from the EGFR targeted therapy.

In this study, we describe a novel function of TNNC1 (Troponin C1, Slow Skeletal and Cardiac Type), a component of actin-bound troponin, as a tumor suppressor of lung adenocarcinoma (LUAD). First, the expression of TNNC1 was strongly down-regulated in cancer tissues compared to matched normal lung tissues, and down-regulation of TNNC1 was shown to be strongly correlated with increased mortality among LUAD patients. Interestingly, TNNC1 expression was enhanced by suppression of KRAS , and ectopic expression of TNNC1 in turn inhibited KRAS G12D -mediated anchorage independent growth of NIH3T3 cells. Consistently, activation of KRAS pathway in LUAD patients was shown to be strongly correlated with down-regulation of TNNC1 . In addition, ectopic expression of TNNC1 inhibited colony formation of multiple LUAD cell lines and induced DNA damage, cell cycle arrest and ultimately apoptosis. We further examined potential correlations between expression levels of TNNC1 and various clinical parameters and found that low-level expression is significantly associated with invasiveness of the tumor. Indeed, RNA interference-mediated down-regulation of TNNC1 led to significant enhancement of invasiveness in vitro . Collectively, our data indicate that TNNC1 has a novel function as a tumor suppressor and is targeted for down-regulation by KRAS pathway during the carcinogenesis of LUAD.

Aim: The present study investigated whether there is intratumoral heterogeneity of oncogenic driver mutations within surgically-resected tumors and between surgical specimens and percutaneous biopsy samples., Patients and Methods: Thirty-four patients who underwent surgery for lung adenocarcinoma were studied. We obtained four to five snap-frozen samples from each surgical specimen. Mutational analyses of epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral homolog (KRAS), v-raf murine sarcoma viral oncogene homolog B (BRAF), and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit-alpha (PIK3CA) genes were performed and then compared in multiple surgical specimens and between surgical and percutaneous biopsy samples., Results: EGFR and KRAS mutations were detected in 19 and 2 patients, respectively. Multiple surgical samples from different areas of the tumor had the same mutation genotype in all cases except for one. The 14 biopsy specimens had the same mutational profiles as the corresponding surgical specimens., Conclusion: Heterogeneous distributions of oncogenic driver mutations were not found in surgically-resected lung adenocarcinoma. Small tumor specimens obtained with percutaneous biopsy were suitable for EGFR analyses, thus providing critical information for personalized therapy.

The metastatic potential of non-small cell lung cancer (NSCLC) has been shown to be associated with interactions with the tumor microenvironment, which primarily comprises of cancer-associated fibroblasts (CAFs). Heterotypic cell-cell interactions occur via released signaling molecules and direct physical contact. To investigate the differential contribution of direct cell-cell contact and paracrine signaling factors to NSCLC metastasis, we performed two types of co-cultures: direct co-cultures of the NSCLC cell line H358 with primary cultures of CAFs from patients with resected NSCLC; and indirect co-cultures across a separable membrane. We showed that CAFs more potently induce epithelial-to-mesenchymal transition (EMT) in NSCLC H358 cells through direct contacts than through indirect interactions, as indicated by an elongated and disseminated appearance. Immunocytochemical experiments show that EMT accompanies the expression of mesenchymal cytoskeletal proteins, including vimentin. However, H358 cells proliferate more slowly in direct co-culture than in indirect co-culture. Real-time reverse transcription-polymerase chain reaction (RT-PCR) revealed that H358 cells in direct contact with CAFs up-regulate the expression of the pan-mesenchymal markers α-smooth muscle actin (α-SMA), fibroblast activation protein (FAP), transforming growth factor-β (TGFβ) signaling effector SMAD family number-3 (SMAD3), and hedgehog signaling effector GLI family zinc finger-1 (GLI1), compared with the indirect co-culture system. Furthermore, we found that the direct GLI1 transcription targets snail family zinc finger-1 (SNAI1) and SNAI2 are up-regulated, suggesting that the hedgehog signaling pathway is active in direct co-culture. A scratch wound assay showed that direct contact co-culture increases the motility of H358 cells. In conclusion, these findings provide evidence that paracrine factors and direct physical contact between NSCLC cells and CAFs might control the metastatic potential of NSCLC through the hedgehog signaling pathway.

The metastatic potential of non-small cell lung cancer (NSCLC) cells has been shown to be associated with the tumor microenvironment. Cancer-associated fibroblasts (CAFs) are a major component of the tumor microenvironment, regulating tumor cell function by secreting growth factors, chemokines, and extracellular matrix (ECM). In this study, we examined the role of CAFs in the tumor progression of NSCLC. Firstly, we established primary cultures of CAFs and matched normal fibroblasts (NFs) from patients with resected NSCLC. CAFs exhibited greater expression of the pan-mesenchymal marker α-smooth muscle actin (α-SMA) than did NFs, although they displayed similar morphology. Furthermore, we employed a direct co-culture assay with human NSCLC A549 and H358 cells, and found that CAFs were more potent in inducing the epithelial-to-mesenchymal transition (EMT) phenotype than NFs, as indicated by an elongated and disseminated appearance. CAF-induced EMT led to an increase in motility and a decrease in proliferation of NSCLC cells through SMAD family number-3 (SMAD3)-dependent up-regulation of the growth inhibitory gene p21(CIP1) [cyclin-dependent kinase inhibitor-1A (CDKN1A)] and α-SMA. Taken together, these findings provide evidence that lung CAFs have tumor-promoting capacity distinct from NFs and might play a significant role in the metastatic potential of NSCLC.

Primary tumors in certain metastatic cases have potential dissemination mechanisms. However, they often lack the potential to colonize distant microenvironments, and consequently the disseminated cancer cells enter into a state of latency which can last for years. In order to investigate the metastatic colonization potential at the gene expression level, we compared such primary tumors with their matching, actively proliferating metastatic tumors. Six pairs of colon-to-lung metachronous tumor samples were examined for the expression levels of 84 well-known metastatic genes using the quantitative RT-PCR-based PCR Array technology. The unsupervised hierarchical clustering of all 12 samples together, resulted in the formation of one closely related cluster by the primary tumors, but highly diversified ones by the metastatic tumors. A pair-wise comparison of the matching primary-metastatic tumors showed that different groups of genes were activated in the lung metastases. Therefore we charted specific genes involved in the genetic diversification processes. A number of these genes showed similar differential expression (ΔCt) patterns in all the patients. These were the cancer cell-, the microenvironment- and the stem cell-specific gene groups. In conclusion, the results suggest that the primary colorectal cancer cells are diversified as regards colonization of the lung, which could explain why the effective therapies for primary colorectal cancers are often not appropriate for controling the growth of pulmonary metastases.