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Hoshino A.,University of Tokyo | Hoshino A.,Research Center for Innovative Oncology | Ishii G.,Research Center for Innovative Oncology | Ito T.,University of Tokyo | And 7 more authors.
Cancer Research

During the metastatic process, cancer cells interact with vascular adventitial fibroblasts (VAF), which are the main components of the outermost connective tissue layer of blood vessels. This activity suggests the presence of a specific tumor microenvironment in the perivascular area. The s.c. coinjection of human lung adenocarcinoma cell lines (A549, PC-14, and CRL-5807) and human VAF (hVAF) resulted in a high rate of tumor formation, compared with the coinjection of these cell lines and human lung tissue-derived fibroblasts (hLF). A cDNA microarray analysis revealed a higher expression level of podoplanin in hVAFs than in hLFs (4.7-fold). Flow cytometry analysis also showed a higher expression level of podoplanin in hVAFs (43% ± 17.5%) than in hLFs (16% ± 10.3%). Sorted podoplanin-positive hVAFs displayed enhanced tumor formation, lymph node metastasis, and lung metastasis of A549 compared to sorted podoplanin-negative hVAFs. Knockdown of podoplanin in hVAFs decreased the augmenting effect of tumor formation and in vitro colony formation. The overexpression of podoplanin in hVAFs hastened the tumor formation of A549, compared with control hVAFs. Furthermore, the analysis of small-sized human lung adenocarcinoma (n = 112) revealed that patients with podoplanin-positive cancer-associated fibroblasts had a significantly higher rate of lymph node metastasis and a high risk of recurrence. These results indicate a promotive effect of hVAFs mediated by podoplanin on cancer progression and suggest that the perivascular environment may constitute a specific niche for tumor progression. ©2011 AACR. Source

Sano M.,National Cancer Center Research Institute and Central Hospital | Sano M.,Matsumoto University | Aoyagi K.,National Cancer Center Research Institute and Central Hospital | Takahashi H.,Chubu University | And 13 more authors.
International Journal of Oncology

Prognosis of cancers with lymph node metastasis is known to be very poor; however, it is still controversial whether metastatic potential can be evaluated by expression profiles of primary tumors. Therefore, to address this issue, we compared gene expression profiles of 24 esophageal squamous cell carcinomas (ESCCs) with extensive lymph node metastasis and 11 ESCCs with no metastatic lymph node. However, there was no gene cluster distinguishing these two groups, suggesting that lymph node metastasisassociated genes are varied depending on cases or subgroups. Therefore, we applied a recently developed filtering method (S2N') to identify such genes, and successfully extracted 209 genes associated with node status. Among them, overexpression of CALB1, KRT7/CK7, MUC1 and CEA/CEACAM5 in poor prognostic cases with metastatic lymph nodes was confirmed in two sets of ESCCs by RT-PCR. Each often seemed to have glandular cell type-characteristics in both the gene expression and morphology. It was also revealed that FOXA1 siRNA treatment of esophageal cancer cells reduced the mRNA level of both KRT7 and a stabilizer of epithelialmesenchymal transition (EMT) regulator LOXL2, and that both FOXA1 and LOXL2 siRNAs reduced invasion and migration of ESCC cells. In 15 KRT7-expressing ESCCs with metastatic lymph nodes, 60% expressed FOXA1 and 33% expressed both FOXA1 and LOXL2. These results suggest that FOXA1 induces not only KRT7 but also LOXL2 in a subset of poor prognostic ESCCs with metastatic lymph nodes, and it is also plausible, that other FOXA1 downstream genes could be therapeutic targets of poor prognostic ESCCs. Source

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