Identification of circulating miRNAs profiles that distinguish malignant pleural mesothelioma from lung adenocarcinoma.

Accurate diagnosis of malignant pleura mesothelioma (MPM) is challenging. Differential diagnosis of MPM versus lung adenocarcinoma (AD) is particularly difficult, yet clinically important since the two neoplasias call for different treatment approaches. Circulating miRNA-profiling to identify miRNAs that can be used to distinguish MPM from AD has not been reported. We conducted a wide screening study of miRNA profiles in serum pools of MPM patients (N = 11), AD patients (N = 36), and healthy subjects (N = 45) to identify non-invasive biomarkers for differential diagnosis of MPM and AD, using deep sequencing. Sequencing detected up to 300 known miRNAs and up to 25 novel miRNAs species in the serum samples. Among known miRNAs, 7 were upregulated in MPM and 12 were upregulated in AD compared to healthy controls. Of these, eight were distinctive for AD and three were unique for MPM. Direct comparison of the miRNA profiles for MPM and AD revealed differences in miRNA levels that could be useful for differential diagnosis. No differentially expressed novel miRNAs were found. Further bioinformatics analysis indicated that three upregulated miRNAs in MPM are associated with the p38 pathway. There are unique alterations in serum miRNAs in MPM and AD compared to healthy controls, as well as differences between MPM and AD profiles. Differing miRNA levels between MPM and AD may be useful for differential diagnosis. A potential association to p38 pathway of three upregulated miRNAs in MPM was revealed.

Differential expression of STAT5 and Bcl-xL, and high expression of Neu and STAT3 in non-small-cell lung carcinoma.

Experimental evidence suggests that in lung cancer, development, progression and an increased proliferation rate can be linked to apoptosis-related factors. The objective of this study is to evaluate the status of Neu, signal transducer and activator of transcription (STAT)-3, STAT5 and Bcl-xL expression in non-small-cell lung cancer. We investigated the immunohistochemical expression of these proteins in 92 non-small-cell lung cancer specimens to establish their role in lung cancer pathogenesis. Neu was overexpressed in 65% of cases, and although STAT3 was overexpressed in 52.1% in cytoplasm, it was expressed in nucleus (activated) in 60.8%. Meanwhile, STAT5 was found overexpressed in 41.3% in cytoplasm and 32.6% in nucleus. Thus, Bcl-xL was overexpressed in cytoplasm in 81.5%. Interestingly, we found nuclear expression of Bcl-xL in 30.4% of cases. Finally, we found correlation among histological types of lung cancer and nuclear expression of both STAT5 (P=0.005) and nuclear Bcl-xL (P=0.003). Besides, nuclear expression of Bcl-xL was correlated with TNM stage IV (distant metastasis) (P=0.02). These results suggest for the first time, a relevant role for STAT5 and Bcl-xL as apoptosis-regulatory proteins in the pathogenesis of lung cancer, and overexpression of both Neu and activated STAT3, could be related with the proliferation rate in lung carcinoma cells.

Quality control study on negative gynecological cytology in Mexico.

An external evaluation of the quality of diagnosis of gynecological cytology specimens (Papanicolaou or "Pap" tests) in the Cytopathological Laboratory at the Mexico General Hospital was performed, with evaluation of 6,011 Pap tests randomly selected from 31,378 Pap studies previously reported as negative during 1988-1989. These tests were part of the early detection program for cervical cancer run by the Ministry of Health of Mexico City. A quality index for specimens was constructed based on the presence of endocervical cells, mucus, and squamous metaplastic cells. The index of false negatives for the diagnosis of cervical neoplasm in this sample which correspond to diagnostic error by the examiner was 0.18% (11). The constructed quality index revealed that 64.1% of specimens were low quality. The correlation between diagnostic error and low quality was .87. Results indicate that laboratories participating in early detection programs for cervical cancer in developing countries need to implement (1) external evaluation programs for Pap diagnosis; (2) permanent training programs in registration; and (3) monitoring procedures for collection, fixation, and transportation of cytologic materials.