Laminin Immunostaining in Biopsies as a Useful Biomarker of Early Invasion in Actinic Cheilitis and Differential Diagnosis Between Actinic Cheilitis and Lip Cancer: New Insights.

BACKGROUND: Squamous cell carcinoma of the lip (LSCC) and oral cavity can be life-threatening if not diagnosed early. Precancerous lesions like actinic cheilitis (AC), can transform into LSCC. Laminin is a fundamental component for basement membrane (BM) and its integrity may prevent neoplastic invasion. Therefore, laminin immunostaining of BM may be useful in identifying early invasion in actinic cheilitis and thus in the differential diagnosis between AC and invasive LSCC or high-grade epithelial dysplasia (ED). MATERIALS AND METHODS: Biopsies from 46 patients with oral lesions were histologically analyzed and immunohistochemically stained for laminin-1. RESULTS: AC was diagnosed in 34 patients and LSCC in 12 patients, including 3 patients with AC and concomitant high-grade ED/in situ carcinoma. Laminin-1 immunostaining revealed intense and linear expression of the BM in AC with low-grade ED. Loss of laminin expression was observed in LSCC. Intracellular laminin expression in parabasal cells was noted in AC with high-grade ED/in situ carcinoma. CONCLUSION: Laminin immunostaining could be useful in identifying AC cases suspected of early invasion. It could also contribute to the histopathological differential diagnosis between AC with low- and high-grade ED and between AC and invasive LSCC. The findings of this study provide new insights into the mechanism involved in the progression process of AC into LSCC, encouraging preclinical studies that may document the stochastic role of laminin in this process.

Hypoxia inducible factor-1 alpha and vascular endothelial growth factor in biopsies of small cell lung carcinoma.

Neoangiogenesis has been documented in small cell lung carcinoma (SCLC). In addition, antiangiogenic therapies are being tested in clinical trials that involve SCLC. However, study of the underlying mechanisms has been performed almost exclusively in cell lines. In the current study, we immunostained 30 biopsy samples of SCLC with antibodies to hypoxia inducible factor-1 alpha (HIF-1 alpha), vascular endothelial growth factor (VEGF), vascular endothelial growth factor-receptor 1 (VEGF-R1/flt-1) and vascular endothelial growth factor-receptor 2 (VEGF-R1/flk-1). The immunoreactivity was analyzed using a bivariate Spearman correlation test and linear regression analysis. We found significant correlation between HIF-1 alpha nuclear staining and VEGF staining. Moreover HIF-1 alpha+/VEGF+ cases were associated with poor survival. We also found a positive correlation between VEGF and VEGF-R2 expression. We suggest that a HIF-1 alpha/VEGF angiogenic pathway may exist in vivo in SCLC, similar to that in non-SCLC. Our data also suggest a potential VEGF/VEGFR-2 autocrine pathway in SCLC. The inclusion of novel inhibitors to HIF-1 alpha and other factors may optimize antiangiogenic interventions in SCLC.

High-risk human papillomavirus (HPV) in parotid lesions.

Although several studies have reported that oropharyngeal infection with HPV may predispose to tumorigenesis, little is known about the etiological factors of salivary gland tumors and the presence of HPV. We studied 9 parotid lesions for HPV infection including an oncocytoma, an acinic cell carcinoma, a high-grade adenocarcinoma, a low-grade polymorphous adenocarcinoma, a Warthin's tumor and 2 pleomorphic adenomas, a lymphoepithelial cyst and a lipoma of the parotid gland. DNA was extracted from formalin-fixed and paraffin-embedded tissue sections. Solution PCR for HPV detection was performed using the GP5+/GP6+ primers, while HPV typing was carried out by multiplex PCR for HPV6, 11, 16, 18, and 33; positive samples were recorfirmed by PCR with specific primers for each type. Quantitative real-time PCR for the high-risk HPV genotypes 16, 18, 31, 33, 35, 52, 58 and 67 was also performed to quantitate the viral load. Finally, in situ PCR was employed with HPV16-specific primers by direct-detection method. Seven of the 9 parotid lesions were HPV positive while 6 of these 7 had been infected by HPV16 and/or HPV18 oncogenic types. High viral load of highrisk genotypes of HPV was found in the oncocytoma, in one of the pleomorphic adenomas, and in the Warthin's tumor. Finally, in situ PCR indicated that HPV16 amplification occurred in the salivary gland tumors. This is the first time that highrisk HPV genotypes are detected in these histological types of parotid lesions, suggesting the possible involvement of the virus in the disease.

Transcriptional activation of H-ras, K-ras and N-ras proto-oncogenes in human bladder tumors.

In this study we demonstrate the involvement of ras oncogenes in bladder cancer at the level of RNA overexpression. We examined 26 bladder specimens, consisting of paired tumor and adjacent normal tissue and found that H-ras transcripts were overexpressed in 39% of the specimens while K-ras and N-ras in 58% of total specimens. Each tumor specimen had a unique pattern of overexpression for the three ras genes. A competitive-RT-PCR was employed for H-ras and a beta-actin control gene was co-amplified with K-ras or N-ras genes. These results indicate that the involvement of ras oncogenes in bladder cancer could be relative to overexpression of these genes.

Genomic instability and loh at 2 polymorphic sites in the h-ras1 gene.

Several repetitive elements have been associated with and identified in the surrounding region and within the human c-H-ras1 gene. The polymorphism exhibited by these sites provides valuable information regarding the function and structure of the H-ras gene. We have investigated two such polymorphic sites: i) a hexanucleotide microsatellite region (HRMS) within intron 1 of H-ras and ii) the VTR region at the 3' end of the gene. Comparison between normal and tumor tissues from 25 samples of bladder cancer revealed that 5 samples (20%) exhibited LOH at these polymorphic sites indicating that an allelic loss had occured at the H-ras locus. Furthermore, instability was detected in 4 cases at the hexanucleotide locus, while the VTR region was found unaffected. The two polymorphic sites are in a strong linkage disequilibrium in normal tissues, while in tumor tissues with genomic instability this linkage is altered, possibly leading to differential regulation of the H-ras. Also a previously reported allele at the HRMS locus was found to behave in a manner that preserves the linkage between the two polymorphic sites in normal tissues.