Cohypermethylation of p16 and FHIT promoters as a prognostic factor of recurrence in surgically resected stage I non-small cell lung cancer

Biomarkers for the lung cancer diagnosis and their advances in proteomics

Over a last decade, intense interest has been focused on biomarker discovery and their clinical uses. This interest is accelerated by the completion of human genome project and the progress of techniques in proteomics. Especially, cancer biomarker discovery is eminent in this field due to its anticipated critical role in early diagnosis, therapy guidance, and prognosis monitoring of cancers. Among cancers, lung cancer, one of the top three major cancers, is the one showing the highest mortality because of failure in early diagnosis. Numerous potential DNA biomarkers such as hypermethylations of the promoters and mutations in K-ras, p53, and protein biomarkers; carcinoembryonic antigen (CEA), CYFRA21-1, plasma kallikrein B1 (KLKB1), Neuron-specific enolase, etc. have been discovered as lung cancer biomarkers. Despite extensive studies thus far, few are turned out to be useful in clinic. Even those used in clinic do not show enough sensitivity, specificity and reproducibility for general use. This review describes what the cancer biomarkers are for, various types of lung cancer biomarkers discovered at present and predicted future advance in lung cancer biomarker discovery with proteomics technology.

Specific 50'CpG island methylation signatures of FHIT and p16 genes and their potential diagnostic relevance in Indian breast cancer patients

Even after tremendous molecular studies, early detection,more accurate and sensitive diagnosis, and prognosis of breast cancer appear to be a riddle so far. To stab the enigma, this study is designed to envisage DNA methylation signatures as cancer-specific and stage-specific biomarkers in Indian patients. Rigorous review of scattered scientific reports on aberrant DNA methylation helped us to select and analyze a potential tumor suppressor gene pair (FHIT and p16 genes) in breast cancer patients. Methylation signatures from 232 primary sporadic breast cancer patients were pinpointed by methylation-specific PCR (MSP). To increase the sensitivity, we combined both MSP and expression studies (RT-PCR and Northern blotting) in a reproducible manner. Statistical analysis illustrated that hypermethylation of FHIT gene ( p < 0.0001) and p16 gene ( p=0.04) may be used as a potential diagnostic marker to diagnose the early and locally advanced stages of breast cancer. Additionally, the study authenticates the dependency of methylation and expressional loss of p16 gene on FHIT gene silencing. This observation not only describes the severity of disease when both genes are silenced but also drives to speculate the molecular cross talk between two genes or genetic pathways dictated by them separately.

Potential biomarkers involving IKK/RelA signal in early stage non-small cell lung cancer

The clinical relevance of nuclear factor kappaB (NF-kappaB) and its regulatory molecules on prognosis of patient with early stages of non-small cell lung cancer (NSCLC), remains unclear. Therefore, we conducted biomarker analyses with survival in patients with stages I and II NSCLC. Tumor samples were collected from 88 patients with early-stage NSCLC (stages I, II). A minimum follow-up period of 5 years was required. RelA, phosphorylated I kappaB (pI kappaB alpha), pIKK alpha/beta were detected by immunostaining. NF-kappaB DNA binding activity was assessed by electrophoretic mobility shift assay. Association of clinical and pathologic variables (e.g. sex, age, pathologic stage) with relevant molecules was determined by Pearson's chi(2) test or Fisher's exact test. Survival analysis based on single expression of RelA, pI kappaB alpha, pIKK alpha/beta as well as composite expressions were evaluated using Cox proportional hazards regression models, and log rank test followed Kaplan-Meier estimates. RelA, pI kappaB alpha, pIKK alpha/beta were observed as increased expression in NSCLC tissues compared with adjacent normal tissues and normal lung tissues. These molecules were associated with tumor-node-metastasis stages, T stages and histological status, respectively. Among the molecules analyzed, RelA and pI kappaB alpha-positive were statistically significant predictors of patient death in the entire patient population adjusted by age, gender and smoking status; furthermore both RelA and pI kappaB alpha-positive was the strongest prognostic indicators of poor prognosis by univariate and multivariate analyses. Borderline positive correlations were observed between RelA and pI kappaB alpha or pIKK alpha/beta expression. In this cohort of early-stage NSCLC patients, molecular markers, especially composite application of multiple biomarkers (both nuclear RelA and cytoplasmic pI kappaB-alpha expression) that independently predict overall survival have been identified.

Survival after surgery in stage IA and IB non-small cell lung cancer

RATIONALE

Whether histologic subtype of non-small cell lung cancer (NSCLC) has an important effect on prognosis after surgery is unknown.

OBJECTIVES

We hypothesized that we could predict mortality more effectively by integrating precise tumor size and histology rather than relying on conventional staging.

METHODS

We used the SEER (Surveillance, Epidemiology, and End Results) registry. Inclusion criteria were as follows: (1) primary squamous cell or adenocarcinoma; (2) potentially curative surgery, defined as a lobectomy or bilobectomy; (3) lymph node dissection performed; and (4) pathologic stage IA or IB.

MEASUREMENTS AND MAIN RESULTS

From 1988 to 2000, 7,965 patients were included. For both all-cause and lung cancer-associated mortality, tumor size demonstrated the strongest association (log-rank P < 0.0001 for each). When tumors were small (</=2 cm), lung cancer-associated mortality was similar for adenocarcinoma when compared with squamous cell carcinoma. When tumors were 3 cm or larger in size, lung cancer-associated mortality was higher for adenocarcinoma. The increased risk of lung cancer-associated mortality with adenocarcinoma was more pronounced in those younger than 65 years. Survival prediction using precise size and histology had much better discriminatory power than conventional TNM (tumor-node-metastasis) staging (P = 0.005).

CONCLUSIONS

Staging that takes into account size, histology, late recurrence risk, and patient age is more accurate than the current TNM system and is clinically relevant because improved prediction can facilitate better decisions on the use of adjuvant chemotherapy.

Combined prognostic value of both RelA and IkappaB-alpha expression in human non-small cell lung cancer

BACKGROUND

We sought to investigate the prognostic significance of nuclear factor (NF)-kappaB activity, especially nuclear RelA and IkappaB-alpha expression patterns, in non-small cell lung cancer (NSCLC).

METHODS

A total of 116 patients with pathologically confirmed stage I to II NSCLC were included. Immunohistochemical analysis and electrophoretic mobility shift assays of NF-kappaB were performed to determine RelA and phosphorylated IkappaB-alpha staining, and DNA binding activity of NF-kappaB in human NSCLC. Downstream genes, including VEGF and IL-8, were also assessed. The prognostic significance of a single expression of RelA, phosphorylated IkappaB-alpha, and b-composite expressions was evaluated by Cox proportional hazard regression models and by Kaplan-Meier survival analyses. Correlation between RelA/IkappaB-alpha expression status and clinicopathological features of NSCLC was also analyzed.

RESULTS

NF-kappaB DNA binding activity, VEGF, and IL-8 showed correlation with nuclear RelA and cytoplasmic pIkappaB-alpha expression. Expression of nuclear RelA/NF-kappaB showed an increase in NSCLC tissue compared with adjacent normal tissue and normal lung tissue. There was a positive correlation between NF-kappaB activation (nuclear translocation of RelA) and tumor clinicopathological features such as tumor grade, including T stages, N stages, and tumor, node, metastasis system stages, smoking status, and age. Positive correlation was observed between nuclear RelA and cytoplasmic pIkappaB-alpha. Both nuclear RelA and cytoplasmic pIkappaB-alpha were associated with poor prognosis by univariate and multivariate analyses.

CONCLUSIONS

Nuclear RelA and cytoplasmic pIkappaB-alpha expression are associated with a poorer prognosis in NSCLC patients. In particular, composite application of these two biomarkers might be of greater value than application of a single marker to identify patients at high risk, even at an early clinical stage.

Biomarkers for lung cancer: clinical uses

PURPOSE OF REVIEW

Biomarkers for lung cancer may be used for risk stratification, early detection, treatment selection, prognostication and monitoring for recurrence. All these areas of clinical management would benefit from sensitive and specific, noninvasive, cost-effective biomarkers.

RECENT FINDINGS

Significant progress has been made in understanding the steps involved in lung carcinogenesis and in the development of novel technologies for biomarker discovery. Over the last 3 years research into prospective lung cancer biomarkers has proliferated, especially in the areas of early detection and prognostication. The most active areas of research have been in promoter methylation, proteomics and genomics. Many investigators are adopting panels of serum biomarkers in an attempt to increase sensitivity. The development of targeted lung cancer therapy has engendered interest in markers to identify the optimal candidates for these therapies.

SUMMARY

Much progress has been made in the last 3 years in the identification and validation of new biomarkers for the early diagnosis of lung cancer. The biomarkers require additional studies before they can be used clinically. Markers to identify lung cancer patients who may benefit from targeted therapy have been developed more rapidly and may be used now in some clinical situations.

The association of p16(INK4A) and fragile histidine triad gene expression and cervical lesions

OBJECTIVE

This cross-sectional study was intended to assess the association between immunohistochemical analysis of p16 and fragile histidine triad (FHIT) and the presence of precancerous cervical lesions.

MATERIALS AND METHODS

Women seen at Pérola Byington Hospital, São Paulo, Brazil, with histologically confirmed cervicitis (n = 31), cervical intraepithelial neoplasia (CIN) 1 (n = 30), CIN 2,3 (n = 30), and cervical cancer (n = 7) had also cervical material collected for liquid-based cytology, human papillomavirus Hybrid Capture 2 (HC2) test, and p16 and FHIT immunohistochemical reactions.

RESULTS

p16 and FHIT reactions were scored as the following: <1%, 1% to 5%, >5% to 25%, and >25%. Receiver operating curve analysis was used to select p16 and FHIT score cutoffs for further categorical analyses. All but one of the 37 CIN 2,3/cancer cases had a p16 score of greater than 1% to 5%. Among the 61 cervicitis/CIN 1 cases, 46 (75%) had a p16 score lower than 1% to 5%. In contrast, no association of FHIT expression and severity of cervical lesions could be demonstrated in this data set. Receiver operating curve analyses suggested the score of 1% to 5% for p16 as the cutoff that best discriminates CIN 2,3/cancer from cervicitis/CIN 1. No cutoff for FHIT scores could be suggested with data set.

CONCLUSIONS

p16, but not FHIT expression, has the potential to be used as complementary diagnostic tool to investigate human papillomavirus-induced cervical lesions, if these results are confirmed in larger studies.

Promoter hypermethylation of RASSF1A and RUNX3 genes as an independent prognostic prediction marker in surgically resected non-small cell lung cancers

Aberrant methylation of promoter CpG islands is known to be a major inactivation mechanism of the tumor suppressor and tumor-related genes. Some published studies suggest a relationship to exist between the methylation status of several genes and the prognosis in non-small cell lung cancer (NSCLC); hypermethylation of the specific genes may be expected to serve as a biomarker for the prognosis, after a curative resection of NSCLC. To determine the relationship between the methylation status of the tumor suppressor and the tumor-related genes, and the clinicopathologic characteristics, including the survival rate, in patients with NSCLC after a surgical resection, we studied methylation in 10 genes (DAPK, FHIT, H-cadherin, MGMT, p14, p16, RAR-beta, RASSF1A, RUNX3, and TIMP-3) in 101 NSCLC cases by methylation-specific PCR (MSP). The methylation frequencies of the 10 genes examined in NSCLC were 26% for DAPK, 34% for FHIT, 26% for H-cadherin, 14% for MGMT, 8% for p14, 27% for p16, 38% for RAR-beta, 42% for RASSF1A, 25% for RUNX3, and 12% for TIMP-3. Clinicopathologically, the patients with all stages of disease who had positive RASSF1A, RUNX3, or H-cadherin methylation status were found to have a significantly shorter duration of survival, as compared with the patients with a negative methylation status for those genes (RASSF1A:P=0.023, RUNX3:P=0.035, H-cadherin:P=0.039) in univariate analysis. Thereafter, while limiting our examination to patients with stage I disease, the patients who had a positive RASSF1A or RUNX3 methylation status were found to have a significantly shorter duration of survival, in comparison to the patients with negative methyaltion status for each of those genes (RASSF1A:P=0.022, RUNX3:P<0.01) in univariate analysis. Next, the histological differences were recognized that the patients with RUNX3 methylation had a shorter duration of survival in adenocarcinomas (ACs) (P=0.045), in contrast to those with RASSF1A methylation who had a shorter duration of survival in squamous cell carcinomas (SCCs) (P=0.021). In multivariate analysis, both positive RASSF1A methylation status, and positive RUNX3 methylation status were found to be independent prognostic factors (RASSF1A:P=0.031, RUNX3:P=0.028), as was TNM stage (P=0.004) and pleural involvement (P=0.037). In conclusion, the hypermethylation of RASSF1A or RUNX3 gene is therefore a useful biomarker to predict the prognosis in NSCLC, particularly RASSF1A due to SCCs and RUNX3 due to ACs.

Epigenomics in respiratory epithelium carcinogenesis: prevention and therapeutic challenges

Respiratory epithelium carcinogenesis is currently considered as the phenotypic aspect of serial genetic and epigenetic aberrations resulting in deregulation of cellular homeostasis. Recent data indicate that DNA demethylating agents and histone deacetylase inhibitors might act synergistically for the prevention of cancer development throughout the carcinogen-exposed epithelium. Preliminary clinical trials have shown encouraging results using these new molecules in lung carcinomas therapeutics. However, the caveats that should be overtaken for efficacious antitumour activity have also emerged. Setting the context in which epigenetic modifications contribute to carcinogenesis evolution is of paramount importance in order to optimize the potency of the current and future epigenome targeting agents.

Coexpression of Fragile Histidine Triad and c-kit Is Relevant for Prediction of Survival in Patients with Small Cell Lung Cancer

BACKGROUND

In a retrospective analysis of 195 patients with small cell lung cancer (SCLC), we examined the prognostic value of a coexpression of fragile histidine triad (FHIT) protein and c-kit on patient's survival.

METHODS

As assessed by immunohistochemistry using formalin-fixed, paraffin-embedded tissue sections, tumors of 195 patients with SCLC were evaluated for FHIT and c-kit coexpression.

RESULTS

Coexpression of FHIT and c-kit was observed in 53.3%; a positive expression of either FHIT or c-kit was found in 40.5%. Complete lack of FHIT and c-kit (6.2%) was associated with a significantly shorter survival time for the patients with a mean of 122 +/- 45 days compared with 468 +/- 89 days for patients with lung cancer coexpressing FHIT and c-kit (P = 0.0011). The proportion of FHIT- and c-kit-positive cells within a tumor was also related to survival time. Patients with tumors with a proportion between 0% to 25% of FHIT- and c-kit-positive cells had the worst survival of 157 +/- 34 days compared with 496 +/- 95 days for patients showing >25% FHIT- and c-kit-positive cells (P = 0.0002). Further, variables associated with shorter survival times were low performance status, elevated lactate dehydrogenase level, and advanced tumor stage according to tumor-node-metastasis classification. Multivariate analysis using Cox regression model, including 11 variables, confirmed the prognostic significance of a combined expression of FHIT and c-kit next to tumor stage, performance status, and lactate dehydrogenase level.

CONCLUSIONS

Differential FHIT and c-kit expression was of prognostic relevance for survival in patients with SCLC and therefore provide useful variables for therapeutic decisions.