Pulmonary sarcomatoid carcinomas (PSCs) are currently defined as poorly differentiated non-small-cell carcinomas containing a component with sarcoma or sarcoma-like (spindle and/or giant cell) features. They consist of 5 major histological variants, namely pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, carcinosarcoma, and pulmonary blastoma. The segregation of PSCs into a distinct clinicopathologic entity seems justified on the basis of morphologic, behavioral, and genotypic/phenotypic attributes. As a group, PSCs generally run an aggressive clinical course and may cause major difficulties in the differential diagnosis with other primary and secondary malignancies of the lung. At present, PSCs are believed to represent a family of carcinomas "in transition," in which diverse pathways of clonal evolution account for histological differences of a common ancestor lesion. The sarcomatous or sarcomatoid component of these tumors is thought to derive from carcinoma cells during the progression of carcinogenesis through the activation of an epithelial-mesenchymal transition program leading to sarcomatous transformation or metaplasia (conversion paradigm). Conceivably, targeting the epithelial-mesenchymal transition program could become a valid therapeutic strategy for these life-threatening tumors, whose sensitivity to current medical manipulation is disappointing.
Previous studies have suggested a "catalytic role" in neoplastic angiogenesis and cancer progression for bone marrow-derived endothelial progenitor cells (EPC). However, preclinical and clinical studies have shown that the quantitative role of marrow-derived EPCs in cancer vascularization is extremely variable. We have found that human and murine white adipose tissue (WAT) is a very rich reservoir of CD45-CD34þ EPCs with endothelial differentiation potential, containing a mean of 263 times more CD45-CD34 þ cells/mL than bone marrow.Compared with marrow-derived CD34 þ cells mobilized in blood by granulocyte colony-stimulating factor, purified WAT-CD34 þ cells expressed similar levels of stemness-related genes, significantly increased levels of angiogenesis-related genes, and increased levels of FAP-a, a crucial suppressor of antitumor immunity.
Gefitinib and erlotinib have different antitumor activity according to the type of the EGFR mutation borne. Report of cases harboring rare mutations can support the decision-making process in this subset of patients.
SUMMARY: p63 is a p53-related gene that encodes for multiple mRNA transcripts with or without (⌬N-p63) transactivating properties on p53-responsive genes. We evaluated for the first time the prevalence and clinical implications of p63 immunoreactivity (IR) and mRNA expression in laryngeal squamous cell carcinomas (LSCCs). Moreover, we also assessed the relationships between p63 expression and p53 gene status. p63 IR was detectable in the basal cell layers of non-neoplastic epithelium and in the whole thickness of dysplastic epithelium. All the 150 LSCCs analyzed were immunoreactive for p63, with 28 (18.7%) cases showing p63 IR in Յ50% of neoplastic cells. ⌬N-p63 mRNA transcripts were detected in all the 23 tumors analyzed, whereas TA-p63 mRNA transcripts were absent in 5 (21.7%) cases. p53 gene mutations were found in 24 (29.2%) of the 82 cases analyzed and p53 IR was found in 58 (53.7%) of the 108 cases analyzed; neither was associated with p63 IR. No significant association was found between p63 IR and patients' survival. Interestingly, down-regulation of TA-p63 mRNA levels was more prevalent in patients with T3-T4 tumors and advanced clinical stage. Although the risk of death for cancer was higher in these patients (40% versus 16.6%), this difference did not reach statistical significance. Our results suggest that abnormal expression of p63 may be involved in the early phases of laryngeal tumorigenesis irrespective of p53 gene status and that TA-p63 mRNA down-regulation, but not p63 IR, may be clinically relevant in patients with LSCC. (Lab Invest 2002, 82:1327-1334.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.