Overexpressed fibroblast growth factor receptor 2 in the invasive front of colorectal cancer: a potential therapeutic target in colorectal cancer.

Fibroblast growth factor receptor 2 (FGFR2) is considered a novel therapeutic target for various cancer. We used a silencing strategy to clarify the effect of reduced FGFR2 expression in human colorectal cancer (CRC) cells. The invasive front of cancer cells exhibited stronger FGFR2 expression than the surface area of the cancers. FGFR2 shRNA-transfected LoVo cells inhibited cell migration, invasion and tumor growth in vitro and in vivo. Thus, FGFR2 plays important roles in CRC progression in association with tumor cell migration, invasion and growth, and FGFR2 might be a novel therapeutic target for CRC.

Nestin is a novel target for suppressing pancreatic cancer cell migration, invasion and metastasis.

Nestin, is a class VI intermediate filament (IF) that is expressed in 30% of pancreatic ductal adenocarcinoma (PDAC) cases, and its expression in PDAC positively correlates with peripancreatic invasion. An expression vector carrying a short hairpin RNA (shRNA) targeting nestin was stably transfected into PANC-1 and PK-45H human pancreatic cancer cells, which express high nestin levels. Alterations in morphology and alignment of actin filaments and α-tubulin were examined by phase-contrast and immunocytochemistry. Effects on cell growth, migration in scratch and Boyden chamber assays, invasion, cell adhesion, and in vivo growth were determined. Differences in mRNA levels were examined by arrays. Nestin shRNA-transfected cells exhibited decreased nestin expression, a sheet-like appearance with tight cell-cell adhesion, increased expression of filamentous F-actin and E-cadherin, and attenuated migration and invasion, both of which were enhanced following nestin re-expression. Expression of α-tubulin, and in vitro cell growth and adhesion were not altered by nestin down-regulation, whereas hepatic metastases were decreased. Thus, nestin plays important roles in pancreatic cancer cell migration, invasion and metastasis by selectively modulating the expression of actin and cell adhesion molecules, and may therefore be a novel therapeutic target in PDAC.

Keratinocyte growth factor induces vascular endothelial growth factor-A expression in colorectal cancer cells.

Keratinocyte growth factor (KGF), which is also called fibroblast growth factor (FGF)-7, belongs to the FGF family. KGF is not commonly produced by human cancer cells, but the KGF receptor (KGFR) is expressed in most cancer cells and particularly highly expressed in well-differentiated types of cancer. Recently, it has been reported that vascular endothelial growth factor (VEGF)-A expression is induced by KGF in pancreatic cancer cells. VEGF-A is produced by some cancer cells and plays important roles in the angiogenesis and metastasis of cancer cells including those in the colorectum. In this study, we examined whether recombinant human KGF (rhKGF) induces major angiogenic growth factors including VEGF-A, FGF-2 and hepatocyte growth factor (HGF) in human colorectal cancer cells (HCT-15), which express a high level of KGFR, but a low or negligible level of KGF. rhKGF significantly increased the VEGF-A expression level in a serum-free medium of HCT-15 cells, but FGF-2 and HGF expression levels were too low to detect. Furthermore, the expression levels of the angiogenic growth factors were evaluated in KGF-transfected HCT-15 cells, which were induced to stably overexpress KGF by KGF gene transfection and mock-transfected cells (Mock). KGF and VEGF-A expression levels in the cells and the protein concentrations in serum-free medium were significantly higher in KGF-transfected HCT-15 cells than in Mock cells. In contrast, the FGF-2 and HGF mRNA expression levels were not significantly different between KGF-transfected HCT-15 cells and Mock cells and the protein concentrations in serum-free medium of the cells were below the detection level. These findings suggest that administration of rhKGF and over-expression of endogenous KGF genes in colorectal cancer cells increase VEGF-A production and may relate to angiogenesis in cancer.

Expression and roles of lumican in lung adenocarcinoma and squamous cell carcinoma.

Lumican is a member of a small leucine-rich proteoglycan family and is highly expressed in several types of cancer cells and/or stromal tissue. Lumican expression in the cytoplasm in advanced colorectal cancer correlates with poor patient prognosis. The expression of lumican in stromal tissues is associated with a high tumor grade, a low estrogen receptor expression level, and young age in breast cancer and is associated with tumor invasion and advanced stage in pancreatic cancer. In this study, we examined the expression and role of lumican in lung cancer including adenocarcinoma (ADC) and squamous cell carcinoma (SqCC). Immunohistochemically, lumican was weakly expressed in vascular smooth muscle cells, perivascular and peribronchial connective tissues and bronchial epithelium of normal lung tissues. In lung cancer tissues, lumican was localized in the cytoplasm of cancer cells and/or stromal tissues adjacent to cancer cells. In ADC, the expression level of lumican in cancer cells correlated with pleural invasion and larger tumor size, but that of lumican in stromal tissues did not correlate with clinicopathological factors. In SqCC, the expression level of lumican in cancer cells correlated with formation of a keratinized pattern, and stromal lumican expression correlated with vascular invasion. In SqCC and ADC, the expression level of lumican in cancer cells did not correlate with patient prognosis. In lung cancer cell lines, lumican mRNA and protein were expressed in LC-1/Sq and EBC-1 cells established from SqCC, and A549, RERF-LC-KJ and PC-3 cells from ADC. The molecular weight of lumican extracted from the cytoplasm of lung cancer cells differed from that in the culture medium owing to glycosylation of the protein. These findings suggest that the expression pattern and the glycosylated type of lumican in cells and stromal tissues correlate with the aggressiveness of lung SqCC and ADC.

Expression of keratinocyte growth factor and its receptor in human endometrial cancer in cooperation with steroid hormones.

The keratinocyte factor (KGF) and its receptor (KGFR) are implicated in tissue development and repair. We studied the expression and functions of KGF and KGFR in association with estrogen and progesterone in human endometrial tissues and cells. In non-cancerous human endometrial tissues in the secretory phase, a strong immunoreactivity of KGF in glands, stromal cells, and smooth muscle cells of spiral arteries was detected; however, in proliferative-phase tissues, the immunoreactivity of KGF or KGFR was weak or absent. Most of the 32 endometrioid adenocarcinoma cases showed positive KGF and KGFR stainings (90.6 and 71.9%, respectively). We then studied, using Ishikawa well-differentiated human endometrial cancer cell line that expresses estrogen receptor (ER) and progesterone receptor (PR), the expression of KGF and KGFR in conjunction with estrogen and progesterone, and observed that the KGFR expression of Ishikawa cells was upregulated by estrogen and that this upregulation was markedly enhanced by the coadministration of progesterone. We also observed that KGF administration to cells, with KGFR upregulated expression, stimulated ERK1/2 phosphorylation and cell adhesion to fibronectin. The implications of the hormone-stimulated KGF-KGFR expressions in the regulation of cell behavior associated with human endometrial cancer are discussed.

Keratinocyte growth factor-transfection-stimulated adhesion of colorectal cancer cells to extracellular matrices.

The keratinocyte growth factor (KGF) regulates cell growth and behavior in an autocrine or paracrine manner. In colorectal cancer tissues, KGF is expressed in tumor cells and adjacent stromal fibroblasts. We have constructed a KGF-gene-transfected cell line (HCT15-KGF) from a colorectal cancer cell line, HCT-15, that expresses the KGF receptor, and studied the effects of KGF on cell behavior, particularly growth and adhesion to extracellular matrices (ECMs). The amount of KGF secreted from HCT15-KGF was significantly higher than that from a mock-transfected cell line (HCT15-MOCK). The modes of growth of these cell lines were similar. The degree of adhesion of HCT15-KGF to ECMs, including type-IV collagen and fibronectin was higher than that of HCT15-MOCK. The expressions of integrins in both cell lines were not significantly different. However, extracellular-regulated kinase-1 and -2 (ERK1/2) phosphorylation and focal adhesion kinase (FAK) expression that regulate the adhesive functions of integrin families were enhanced in HCT15-KGF. U0126, an inhibitor of the ERK upstream regulator MEK, attenuated the adhesion and spreading of HCT15-KGF cells to type-IV collagen. These results indicate that KGF enhances the adhesion of colorectal cancer cells to type-IV collagen through ERK and FAK signaling pathways.

Enhanced expression of keratinocyte growth factor and its receptor correlates with venous invasion in pancreatic cancer.

Keratinocyte growth factor (KGF) and KGF receptor (KGFR) have been implicated in cancer growth as well as tissue development and repair. In this study, we examined whether KGF and KGFR have a role in human pancreatic ductal adenocarcinoma (PDAC). KGFR mRNA was expressed in eight pancreatic cancer cell lines, whereas the KGF mRNA was detected in seven of the cell lines and was absent in MIA PaCa-2 cells. KGFR and KGF immunoreactivity were localized in the cancer cells in 41.5 and 34.0% of patients, respectively. There was a significant correlation between KGFR or KGF immunoreactivity and venous invasion and a significant correlation between the presence of both markers and venous invasion, vascular endothelial growth factor (VEGF)-A expression, and poor prognosis. Exogenous KGF increased VEGF-A expression and release in MIA PaCa-2 cells, and PANC-1 cells stably transfected to overexpress KGF-exhibited increased VEGF-A expression. Moreover, short hairpin-KGFR transfection in MIA PaCa-2 cells reduced the stimulatory effect of exogenous KGF on VEGF-A expression. Short hairpin-KGF transfection in KLM-1 cells reduced VEGF-A expression in the cells. KGFR and KGF may act to promote venous invasion and tumor angiogenesis in PDAC, raising the possibility that they may serve as novel therapeutic targets in anti-angiogenic strategies in PDAC.

[Pathological genomics of keloid fibroblastic cells].

OBJECTIVE: Keloids result from the abnormal repair of the tissues after skin injuries where the pathological overgrowth of large and active fibroblastic cells expands beyond the boundaries of the initiating wound. Imbalanced expression of genes with an as yet unknown regulatory mechanism seems to result in the hypertrophic development of fibroblastic cells and over-productions of collagen. To get information as to genes which function in the actively growing keloid fibroblasts, we have applied a gene expression DNA-microarray technique by analyzing broad range of genes at once in a systematic fashion. METHODS: Differential gene expressions of keloid fibroblastic cell lines against a normal skin fibroblastic cell line, all of the cell lines had been propagated in our lab, were analyzed using a cDNA-microarray technique. mRNA was extracted from the control normal skin cells and the two lines of keloid fibroblastic cells, one from ear-lobe keloid tissue and the other from chest keloid tissue, was subjected to a DNA microarray analysis which includes 1 100 human genes (TaKaRa Intelli Gene Human CHIP 1K Set I) . RESULTS: 8 genes were found to be expressed exclusively in ear-lobe keloid fibroblastic cell lines. Cells from chest keloid were detected to express 17 genes, specifically. Coagulation factor II (thrombin) receptor gene, KIAA0367 protein gene, and matrilin-2 gene were found to be the most commonly expressed genes in the keloid cells. Suppressor genes, like melanoma differentiation associated gene-7, Mda-7 (U16261), were expressed in normal skin fibroblasts but were not expressed in keloid fibroblasts may be implicated in the pathogenesis of the keloid lesions. CONCLUSIONS: Genes expressed specifically in keloid cells may be an adequate pathological diagnostic marker for keloids. Further, Identification of genes that cause cells to develop keloid lesions leads us to gene therapy and prevention of keloids.

[Investigation of p53 polymorphism for genetic predisposition of keloid and hypertrophic scar].

OBJECTIVE: To investigate the codon-72 polymorphism of the tumor suppressor gene p53, codon-72 encodes arginine (Arg) or proline (Pro) for a genetic predisposition,to keloid or hypertrophic scar. METHODS: The distribution of codon 72 polymorphism of p53 gene was analyzed from the 54 keloid and 30 hypertrophic scar(HS)of the Japanese patients with restriction fragment length polymorphism analysis and DNA sequence analysis. RESULTS: The frequency of the Proline-encoding alleles and Arginine-encoding alleles in the hypertrophic scar patients and the piercing-induced ear-lobe keloid patients, was deviated significantly from that in the normal Japanese controls. CONCLUSIONS: The Proline-encoding allele and Arginine-encoding allele could have the risks for the hypertrophic scar and the piecing-induced ear-lobe keloid. Also, the pathogenesis of the hypertrophic scar seems to be different from that of keloid at the molecular level.