Expression Of Hedgehog Signaling Molecules Research Articles

Patched 1 expression in Merkel cell carcinoma.

The relevance of Hedgehog signaling in Merkel cell carcinoma has only been addressed by a few studies with conflicting results. Thus, we aimed to establish the expression of Hedgehog signaling molecules in Merkel cell carcinoma to characterize causes of aberrant expression and to correlate these findings with the clinical course of the patients. Immunohistochemistry was performed for Sonic, Indian, Patched 1 (PTCH1) and Smoothened on patients' tumor tissue. Respective mRNA expression was analyzed in 10 Merkel cell carcinoma cell lines using quantitative real-time polymerase chain reaction. PTCH1 sequencing and DNA methylation microarray analyses were carried out on tumor tissues as well as cell lines. PTCH1 immunoreactivity in Merkel cell carcinoma was similar to that of basal cell carcinomas, which both significantly differed from PTCH1 immunoreactivity in healthy skin. Most PTCH1 mutations found were synonymous or without known functional impact. However, on average, the promoter regions of both PTCH1 were hypomethylated independently from PTCH1 gene expression or Merkel cell polyomavirus status. PTCH1 and GLI1/2/3 genes were differently expressed in different cell lines; notably, there was a significant correlation between GLI2 and PTCH1 mRNA expression. Similar to PTCH1 protein expression in patient tissues, PTCH1 gene expression in Merkel cell carcinoma cell lines is highly variable, but due to the similar methylation pattern across Merkel cell carcinoma cell lines, effects other than methylation seem to be the reason for the differential expression and PTCH1 appears to be upregulated by GLI as a classical Hedgehog target gene.

Expression of hedgehog signaling molecules as a prognostic indicator of oral squamous cell carcinoma

Recent studies have indicated hedgehog pathway plays a role in carcinogenesis of certain cancers. We investigated the clinical significance of its signaling components, including Sonic hedgehog (Shh), Patched (Ptch), and Gli-1, in oral squamous cell carcinoma (OSCC). By immunohistochemistry, we determined Shh, Ptch, and Gli-1 expression in surgical specimens from 40 patients with OSCC. The relationship between expression of these molecules and clinicopathologic variables were assessed by chi-square analysis. Statistical difference of survival was compared using log-rank test. Ptch overexpression was associated with lymphatic metastasis (p = .028). Nuclear Gli-1 overexpression correlated with primary tumor size (p = .001), lymphatic metastasis (p = .011), and tumor recurrence (p = .008). Overexpression of Ptch (p = .020) or Gli-1 (p = .002) in OSCC indicated poor prognosis in the univariate survival analysis. Our results suggest sonic hedgehog (Shh) pathway plays an important role in OSCC progression and should be considered a potential therapeutic target.

Activation of the hedgehog pathway in chronic myelogeneous leukemia patients

BackgroundHedgehog (Hh) signaling pathway is involved in regulation of many tissues development and oncogenesis. Recently, Hh signaling has been identified as a required functional pathway for leukemia stem cells(LSCs), and loss of this pathway impairs leukemia progression.ObjectivesThe aim of this study was to determine the expression of Hedgehog signaling molecules in Chronic Myelogeneous Leukemia (CML) patients and normal people by semiquantitative polymerase chain reaction (PCR) and to correlate mRNA expression to patients' clinical data.ResultsHere, we showed that Sonic hedgehog (Shh), Smoothened (Smo), and Gli1 genes of Hh signaling were significantly upregulated in CML patients when compared with normal people (P < 0.001). The levels of Shh, Smo mRNA in chronic phase of CML patients were obviously lower than that in blast crisis (p < 0.05). There were no significant differences of Shh, Ptch1, Smo, Gli1 mRNA expression found when comparing CML patients of chronic phase(CP) with imatinib(IM) treated or not(p > 0.05).ConclusionsThese findings suggested that activation of the Hh pathway maybe associated with CML progression. Treatment of CML with imatinib, a selective inhibitor of the BCR-ABL tyrosine kinase inhibitor, has no significant influence on the inhibition of Hh pathway of CML-CP patients.

Expression of hedgehog signaling molecules in Merkel cell carcinoma

Expression of hedgehog signaling molecules in Merkel cell carcinoma

Expression of hedgehog signaling molecules in lung cancer

Abnormal hyperactivation of the hedgehog (Hh) pathway has been reported in many types of human cancers, including lung cancer. However, most reports are based on studies of fewer than three Hh target genes and the data vary between different studies. In the present report, we have determined the expression levels of several important components of the Hh pathway in lung cancers by using RT-PCR, in situ hybridization and immunohistochemistry. These molecules include Smoothened (SMO), Rab23, the downstream target platelet-derived growth factor receptor alpha (PDGFRα), hedgehog interacting protein (HIP ) and hepatocyte nuclear factor 3-beta (HNF3β). Our data show that some components of the hedgehog pathway, such as SMO, Rab23 and PDGFRα are expressed in many lung cancer specimens, although other hedgehog target genes are infrequently detected in lung cancer. Loss of HIP expression was found in several cases of lung cancers. Our study indicates that there might be some additional mechanisms involved in the hyperactivation of the Hh pathway. Thus, we suggest that lung cancer with heterogeneous tumor type harboring Hh signaling activation may have some novel and different regulatory mechanisms.

Identification of signature genes for detecting hedgehog signaling activation in gastric cancer

The aim of this study was to investigate the expression of hedgehog signaling molecules in gastric cancer. In situ hybridization, immunohistochemistry and RT-PCR for hedgehog signaling molecules, smoothened (SMO), suppressor of fused [Su(Fu)], and the target genes hedgehog-interacting protein (HIP) and platelet-derived growth factor receptor α (PDGFRα) were performed in 30 gastric cancer and two gastritis specimens. Using in situ hybridization, SMO expression was detected in 18/30 cancerous specimens (60%) as well as in 1/2 gastritis specimens (50%). Su(Fu) was expressed in 15/30 (50%), HIP in 14/30 (≈47%), and PDGFRα in 6/30 (20%) gastric cancer specimens. Despite the heterogeneous expression pattern, SMO, Su(Fu) and PDGFRα transcripts were highly correlated with the HIP transcript in the 30 gastric cancer specimens (p=0.0006, 0.0003 and 0.0441, respectively). Results from the in situ hybridization were further confirmed by RT-PCR for the expression of all of the genes and by immunohistochemistry for SMO expression. The findings revealed a set of genes for detecting Hh signaling activation in gastric cancer.

Expression of hedgehog signaling molecules in Merkel cell carcinoma

The Hedgehog signaling pathway is important for human development and carcinogenesis in various malignancies. One tissue microarray with triplets of 28 samples from 25 patients with Merkel cell carcinoma (MCC) was constructed. Six samples of normal skin and 5 samples of normal oral mucosa served as controls. All samples were analyzed immunohistochemically with antibodies directed against Sonic hedgehog, Indian hedgehog, Patched, Smoothened, Gli-1, Gli-2, and Gli-3. All investigated proteins were frequently and intensely overexpressed in MCCs (Sonic hedgehog, 93%; Indian hedgehog, 84%; Patched, 86%; Smoothened, 79%; Gli-1, 79%; Gli-2, 79%; Gli-3, 86%) compared with control samples. High levels of Patched and Indian hedgehog were significantly associated with an increase in patients overall (p = .015) and recurrence-free survival (p = .011), respectively. Our results indicate that the Hedgehog signaling pathway is strongly activated in MCC and thus may play a role in carcinogenesis.

Expression and regulation of hedgehog signaling pathway in pancreatic cancer

Pancreatic cancer is an aggressive malignancy with a poor prognosis. The overall 5-year survival rate of pancreatic cancer is less than 5%, and has not improved significantly for years. Further understanding of the molecular carcinogenesis of pancreatic cancer is critical for designing effective ways to treat this type of malignancy. In this study, we examine expression of hedgehog signaling molecules in 54 surgically removed pancreatic cancer specimens as well as seven available pancreatic cancer cell lines. We find that expression of Ptch is associated with tumor size, tumor differentiation, lymph node metastasis, and clinical stages, whereas expression of Smo is associated with tumor differentiation and lymph node metastasis. Our studies from pancreatic cancer cell lines indicate that targeted inhibition of hedgehog signaling by Smo signaling inhibitor KAAD-cyclopamine causes hedgehog target gene expression (Gli1) suppression, induces P21 expression and G1 cell population, and reduced expression of Cyclin D1 and IGF2. These results indicate that hedgehog signaling activation is a very common event in pancreatic cancer and that targeted inhibition of hedgehog signaling may be effective in treatment of pancreatic cancer.

The role of hedgehog signaling during gastric regeneration

Hedgehog signaling plays critical roles during embryonic development. It is also involved in tissue regeneration and carcinogenesis in various adult tissues. Moreover, it regulates the maintenance of cancer stem cells and adult stem cells. Although hedgehog signaling is important in gastric carcinogenesis, its role in gastric regeneration has not been previously examined. In the present study, we evaluated the expression and roles of hedgehog signaling during gastric regeneration. Gastric ulcers were induced by serosal application of an acetic acid solution in mice. Sham-operated mice served as controls. The proliferation of gastric progenitor cells was studied using bromodeoxyuridine (BrdU). The expression of hedgehog signaling molecules and the differentiation of gastric progenitor cells were examined by immunohistochemical staining and Western blotting. One day after the induction of gastric ulcer, the proliferation of gastric progenitor cells increased; however, the expression of hedgehog signaling molecules, including sonic hedgehog (Shh), Indian hedgehog (Ihh), desert hedgehog (Dhh), and patched (Ptch1) decreased at the ulcer margin. From 5 days after the induction of gastric ulcer, newly generated gastric glands and their differentiation were observed at the ulcer margin. The expression of hedgehog signaling molecules gradually increased in the newly generated gastric glands of the ulcer margin. Cyclopamine, a specific inhibitor of hedgehog signaling, significantly inhibited the differentiation of mucous cells and parietal cells during the gastric regeneration process. The above results suggest that hedgehog signaling is involved in the differentiation of gastric progenitor cells during the gastric ulcer repair process.

Enhanced expression of hedgehog signaling molecules in squamous cell carcinoma of uterine cervix and its precursor lesions

The hedgehog (Hh)-signaling pathway plays an essential role in normal development. Deregulation of this pathway is responsible for several types of cancers. The aim of this study was to determine the expression pattern and the extent of Hh-signaling molecules in squamous cell carcinoma of uterine cervix and its precursor lesions. A total of 106 uterine cervical cancers and related lesions (37 squamous cell carcinomas, 23 cervical intraepithelial neoplasia (CIN) III, 10 CIN II, four CIN I, 32 normal cervical epithelia) were immunohistochemically analyzed with anti-Shh, Indian Hh (Ihh), Patched (PTCH), Smoothened (Smo), Gli-1, Gli-2, Gli-3 antibodies on paraffin blocks. The results showed that the expression of all the Hh-signaling molecules was greatly enhanced in uterine cervical tumors, including carcinoma and its precursor lesions. The staining pattern was mainly cytoplasmic except for Gli-1/2, whose expression was observed in both cytoplasm and nucleus. In case of Ihh, PTCH, Smo and Gli-1, their expression in normal epithelium was completely absent or rare. The expression of all the seven Hh-signaling molecules mentioned above was significantly increased in CIN II/III and carcinoma, compared with that in normal epithelium (P<0.05). The expression of Shh was increased by double; the first increase occurred in normal epithelium–CIN transition, and the second, during the progression of CIN to carcinoma. These results strongly suggest that the Hh-signaling pathways were extensively activated in carcinoma and CIN of uterine cervix. In conclusion, the Hh-signaling pathways may be involved in carcinogenesis of squamous cell carcinoma of uterine cervix and can be considered as a potential therapeutic target.