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Query: UMLS:C0684249 (lung carcinoma)
 23,830 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study examined the p16 expression status and the P16 gene deletion and methylation status in specimens from Japanese patients with malignant pleural mesothelioma (MPM). Immunohistochemical staining for p16 protein and fluorescence in situ hybridization for the P16 gene were performed using specimens from 30 Japanese patients with primary MPM. The methylation status of the P16 gene was examined in 13 patients whose frozen tumor specimens were available using a methylation-specific PCR assay. Among the 30 patients, the loss of p16 protein expression was observed in 24 patients (80.0%). Twenty-one patients had homozygous deletions, and 9 patients retained the P16 gene. None of the patients with P16 homozygous deletions exhibited p16-positive expression, and 3 patients who retained the P16 gene did not exhibit p16-positive expression. Aberrant P16 methylation was present in two patients with an intact P16 gene but without p16 expression. These results suggest that either a homozygous deletion or methylation is responsible for P16 inactivation. Regarding the prognosis, patients with p16-negative expression had a significantly shorter survival time than those with p16-positive expression (P=0.040). Our study showed that P16 inactivation by homozygous deletions or methylation is a frequent event in Japanese patients with MPMs, relating to poor prognosis. Homozygous deletion is the major cause of P16 inactivation, but methylation also lead to the inactivation of P16 when the P16 alleles are retained.
Lung Cancer 2008 Oct
PMID:Frequent p16 inactivation by homozygous deletion or methylation is associated with a poor prognosis in Japanese patients with pleural mesothelioma. 1839 29

Inhalation of radon is closely associated with an increased risk of lung cancers. While the involvement of Ink4a in lung tumor development has been widely described, the tumor suppressor gene has not been studied in radon-induced lung tumors. In this study, loss of heterozygosity (LOH) analysis of the Cdkn2a locus, common to the Ink4a and Arf genes, was performed on 33 radon-induced rat lung tumors and showed a DNA loss in 50% of cases. The analysis of p16(Ink4a) protein expression by immunohistochemistry revealed that 50% of the tumors were negative for this protein. Looking for the origin of this lack of expression, we observed a low frequency of homozygous deletion (6%), a lack of mutation, an absence of correlation between promoter methylation and Ink4a mRNA expression and no correlation between LOH and protein expression. However, a tendency for an inverse correlation between p16(Ink4a) and pRb protein expression was observed. The expressions of p19Arf, Mmd2 and Mdm4 were not deregulated and only 14% of the tumors were mutated for Tp53. These results indicated that Ink4a/Cdk4/Rb1 pathway deregulation, more than Arf/Mdm2/Tp53 pathway, has a major role in the development of these tumors through p16(Ink4a) deregulation. However, all known mechanisms of inactivation of the pathway do not play a recurrent role in these tumors and the actual origin of the lack of p16(Ink4a) protein expression remains to be established.
Lung Cancer 2009 Mar
PMID:Molecular analysis of the Ink4a/Rb1-Arf/Tp53 pathways in radon-induced rat lung tumors. 1865 78

We examined the methylation status in 100 specimens of lung adenocarcinomas measuring 2cm or less and with bronchioloalveolar carcinoma (BAC) components (Noguchi types A-C) and then compared the methylation status between noninvasive tumors (Noguchi type A or B) and invasive tumors (Noguchi type C). Methylation-specific PCR was used to determine the methylation statuses of p16(INK4a), RASSF1A, CDH13, RARbeta, and Cyclin D2. The methylation index that was regarded as representing the degree of methylation was calculated. We also determined the mutational statuses of EGFR exons 19 and 21 using a PCR-based method. A multivariate analysis showed that the aberrant methylation of p16(INK4a), RASSF1A, and CDH13 was significantly more frequent in invasive tumors than in noninvasive tumors [p16(INK4a), 36.5% versus (vs.) 8.3%, P=0.0023; RASSF1A, 46.2% vs. 14.6%, P=0.0012; CDH13, 42.3% vs. 10.4%, P=0.0006]. The methylation index was significantly higher in invasive tumors than in noninvasive tumors (P=0.004). The methylation of p16(INK4a) was significantly more frequent in EGFR wild-type tumors than in EGFR mutant tumors (P=0.021). Our results indicate the involvement of epigenetic alterations in the progression of adenocarcinoma with BAC components.
Lung Cancer 2009 Sep
PMID:DNA methylation in small lung adenocarcinoma with bronchioloalveolar carcinoma components. 1914 41

CT plays an important role in diagnosis of lung cancer, however has been limited by uncertain detection rate for early stage of non-small-cell lung cancer (NSCLC), particularly central tumors. Genetic analysis of sputum has proven to be useful in diagnosis of NSCLC. We proposed to evaluate efficacy of combing CT and genetic analysis of sputum for noninvasive diagnosis of stage I NSCLC. Genomic copy changes of a panel of lung cancer-related genes, HYAL2, FHIT, p16, and SP-A were analyzed by a mini-chip in sputum from 33 patients with stage I NSCLC and 49 cancer-free controls. The genetic and CT diagnoses were compared with surgical-pathologic stage. CT had higher sensitivity (85%) in detection of lung cancer compared with the mini-chip (70%) (p<0.05), while there was no significant difference in specificity between the two tests (89% vs. 92%, p=0.09). Similarly, CT showed considerably higher sensitivity (93%) in identifying peripheral tumors than did the mini-chip (64%) (p<0.05), whereas there was no difference in specificity between them (98% vs. 96%, p=0.28). However, in detecting central tumors, CT had lower specificity (90%) compared with the mini-chip (98%) (p<0.05), although its sensitivity (79%) was higher than that of the mini-chip (73%) (p=0.05). Combining both tests offered higher sensitivity (91%) than did any single one (85%, 70%, all <0.05), while still keeping 92% sensitivity. In particular, this combined approach yielded higher sensitivity, specificity, and accuracy for diagnosing central cancers compared with CT alone (all p<0.05). The integration of the genetic assay with CT led to improvements in noninvasive diagnosis of stage I NSCLCs, especially central tumors.
Lung Cancer 2009 Oct
PMID:Combined genetic analysis of sputum and computed tomography for noninvasive diagnosis of non-small-cell lung cancer. 1918 17

About 50% of patients presenting with resectable lung cancer develop distant metastases within 5 years. Genomic markers predicting metastatic behaviour of squamous cell lung carcinoma (SCC) are currently underexposed. We analyzed a cohort of patients with primary SCC using array-based comparative genomic hybridization (aCGH) to identify which genomic aberrations are related to metastatic behaviour. The cohort consisted of 34 patients with a follow-up of at least 5 years, 8 with metastases in regional lymph nodes only and 26 patients without any metastases at the time of surgery. Eleven of the latter 26 developed metastases in distant organs within 3 years after surgery. Copy number changes observed in at least 40% of all SCC included gains at chromosomal arms 3q, 5p, 8q, 19q, 20p, 22q and losses at 3p, 4p, 4q, 5q, 8p and 9p. High copy number amplifications were observed at 2p15-p16, 3q24-q29, 8p11-p12, 8q23-q24, and 12p12, containing candidate oncogenes such as BCL11A, REL, ECT2, PIK3CA, ADAM9, MYC and KRAS. Amplification of 2p15-p16 is a novel finding in SCC. Another novel finding is the homozygous deletion observed at 4q33-34.1 in 15% of the SCC cases. Gains at 7q36, 8p12, 10q22, 12p12, loss at 4p14 and the homozygous deletions at 4q occurred significantly more frequent in SCC from patients with lymph node metastases only. SCC from patients with distant metastases showed a significantly higher gain frequency at 8q22-q24 and loss at 8p23 and 13q21, and a significantly lower gain frequency at 2p12 and 2p16 and loss at 11q25 compared with SCC from patients without metastases. Of these, gains at 7q, 8p and 10q were restricted to SCC with lymph node metastasis and gain at 8q was restricted to patients with distant metastasis. Two genomic aberrations, i.e. loss of 4p and gain of 19q12 were observed more frequently in SCC with only lymph node metastases as compared to SCC with distant metastases. In conclusion, we identified genomic aberrations in primary SCC that were related to lymph node or distant metastases.
Lung Cancer 2009 Dec
PMID:Genomic aberrations in squamous cell lung carcinoma related to lymph node or distant metastasis. 1932 46

In effusion cytology, adjuvant techniques are often needed for the differentiation of reactive proliferating mesothelial cells and malignant cells. In the case of malignancy the further challenge is to distinguish metastatic tumors from the primary malignant mesothelioma. Fluorescence in situ hybridization (FISH) of cells in interphase is an accurate method to monitor the genetic status of cells, detecting aneuploid signals and gene deletions. Moreover, it has been proposed that a homozygous deletion of the p16(INK4A) gene could more specifically identify malignant mesothelial cells among the exfoliated cells. The first objective of this study was to adapt the commercial FISH-test, UroVysion originally designed for the cytological diagnosis of bladder cancer, to the analysis of cells in effusions. The second objective was to test the clinical utility of the test. Sixty-eight pleural effusions were evaluated. The cytological diagnosis was malignant in 29 cases, inconclusive in 24 cases and benign in 15 cases. The independently verified final diagnoses were mesothelioma in 21 cases, metastatic cancer in 29 and benign in 18 cases. The algorithm for aneuploidy distinguished almost all tested malignant conditions from benign ones, also those with inconclusive cytology. The 9p21 locus, carrying the p16(INK4A) gene, was homozygously deleted in two of the metastatic cancers, while this was seen in 12 of the 21 malignant mesotheliomas. Thus the commercial UroVysion-test can be used to accurately distinguish malignant and reactive cells in effusions, particularly when cytology is inconclusive. The test may also indicate presence of MM.
Lung Cancer 2010 Apr
PMID:Adaptation of a commercial fluorescent in situ hybridization test to the diagnosis of malignant cells in effusions. 1952 12

The tumor suppressor LKB1 is inactivated in 90% of Peutz-Jeghers cancer syndrome, 30-40% of non-small cell lung carcinoma, and a variety of other cancers, indicating the loss of LKB1 activity is a critical step in oncogenesis. However, current understanding of LKB1 function is largely limited to the results from cancer cells, and how LKB1 inactivation initiates malignant transformation in normal cells remains unclear. Here we ablated endogenous expression of LKB1 in two normal cell lines: human embryonic kidney 293T cells (HEK-293T cells) and human umbilical vein endothelial cells (HUVECs) by LKB1-specific short hairpin RNAs. Downregulation of endogenous LKB1 lead to a facilitated G(1)/S transition, accompanied by a concomitant increase in Rb phosphorylation (Ser(807/811)). Furthermore, reduced expression of p53 and p16 was observed in LKB1 ablated cells, while no differences were detected for cyclin D1 and cyclin E. These results jointly suggest that endogenous LKB1 knockdown accelerates cell cycle progression through G(1)/S checkpoint in HEK-293T cells and HUVECs, which is at least in part, mediated by decline of p53 and p16 pathways. Our findings provided a plausible mechanism by which loss of LKB1 expression in normal cells contributes to the formation of malignancies.
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PMID:Endogenous LKB1 knockdown accelerates G(1)/S transition through p53 and p16 pathways. 2036 93

This study determined whether expression levels of a panel of biologically relevant microRNAs can be used as prognostic or predictive biomarkers in patients who participated in the International Adjuvant Lung Cancer Trial (IALT), the largest randomized study conducted to date of adjuvant chemotherapy in patients with radically resected non-small cell lung carcinoma (NSCLC). Expression of miR-21, miR-29b, miR-34a/b/c, miR-155, and let-7a was determined by quantitative real-time PCR in formalin-fixed paraffin-embedded tumor specimens from 639 IALT patients. The prognostic and predictive values of microRNA expression for survival were studied using a Cox model, which included every factor used in the stratified randomization, clinicopathologic prognostic factors, and other factors statistically related to microRNA expression. Investigation of the expression pattern of microRNAs in situ was performed. We also analyzed the association of TP53 mutation status and miR-34a/b/c expression, epidermal growth factor receptor and KRAS mutation status, and miR-21 and Let-7a expression. Finally, the association of p16 and miR-29b expression was assessed. Overall, no significant association was found between any of the tested microRNAs and survival, with the exception of miR-21 for which a deleterious prognostic effect of lowered expression was suggested. Otherwise, no single or combinatorial microRNA expression profile predicted response to adjuvant cisplatin-based chemotherapy. Together, our results indicate that the microRNA expression patterns examined were neither predictive nor prognostic in a large patient cohort with radically resected NSCLC, randomized to receive adjuvant cisplatin-based chemotherapy versus follow-up only.
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PMID:MicroRNA expression and clinical outcomes in patients treated with adjuvant chemotherapy after complete resection of non-small cell lung carcinoma. 2179 42

The cell cycle governs the proliferation and growth of cells and is strictly controlled by some regulators including cyclins, CDKs and CKIs. Germ-line and somatic mutations in cell cycle genes were frequently observed in a subset of cancers including non-small cell lung cancer (NSCLC). In this study, we hypothesized that potentially functional single nucleotide polymorphisms (SNPs) in cell cycle genes may contribute to the prognosis of NSCLC in China. 54 potentially functional polymorphisms in key cell cycle genes (CDK1, CDK2, CDK4, CDK6, CDK7, CCND1, CCND2, CCND3, CCNE1, CCNA1, CCNA2, CCNB1, CCNH, p15, p16, p18, p19, p21, p27, Cdc25A and Cdc25B) were genotyped by using Illumina SNP genotyping platform to evaluate their associations with survival of NSCLC in a clinical cohort of 568 patients. We found that p18 rs3176447 variant genotypes were significantly associated with the decreased risk of death of NSCLC patients (adjusted HR=0.74, 95% CI=0.57-0.97 in an additive model; adjusted HR=0.76, 95% CI=0.55-0.97 in a dominant model); however, p21 rs2395655 variant genotypes were significantly associated with the increased risk of death (adjusted HR=1.21, 95% CI=1.02-1.42 in an additive model; adjusted HR=1.38, 95% CI=1.07-1.78 in a recessive model). Furthermore, the combined effect of unfavorable genotypes for these two SNPs was more prominent in patients with squamous cell carcinoma, late stage and without chemo- or radio-therapy. Although the exact biological function remains to be explored, our findings suggest possible association of polymorphisms of p18 and p21 with the prognosis of NSCLC in a Chinese population. Further large and functional studies are needed to confirm our findings.
Lung Cancer 2011 Jul
PMID:Potentially functional polymorphisms in cell cycle genes and the survival of non-small cell lung cancer in a Chinese population. 2114 15

The p16(INK4A) gene is frequently inactivated in nonsmall cell lung carcinoma (NSCLC) by either mutations, deletions or DNA methylations. To assess the biological significance of p16(INK4A) inactivation in the development of NSCLC, full-length p16(INK4A) cDNA was introduced into NSCLC cell lines, A549 and H322, in which p16(INK4A) was homozygously deleted. NSCLC cells transfected with the p16(INK4A) expression vector formed colonies in 20-68% of those with a control vector, and exogenous p16(INK4A) protein was expressed in 4 of 68 A549-derived clones and none of 29 H322-derived clones, respectively. A549-derived clones which stably expressed the exogenous p16(INK4A) gene showed significant decrease in growth rate in vitro and tumorigenicity in vivo in proportion to the level of p16(INK4A) expression. Furthermore, the cell cycle of these cells significantly delayed with accumulation of cells in G1 phase. Micro-injection of p16(INK4A) expression vector also revealed that p16(INK4A) blocked S phase entry in both A549 and H322 cells. These results suggest that the restoration of the p16(INK4A) function suppresses the growth of NSCLC cells by induction of G1 arrest in the cells. Therefore, inactivation of p16(INK4A) may play an important role in the enhancement of unregulated NSCLC growth in vivo.
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PMID:Growth suppression of non-small cell lung carcinoma cells by the introduction of the p16(INK4A) gene. 2153 40


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