A New Plasmacytoid Dendritic Cell-Based Vaccine in Combination with Anti-PD-1 Expands the Tumor-Specific CD8+ T Cells of Lung Cancer Patients.

The purpose of immune checkpoint inhibitor (ICI)-based therapies is to help the patient's immune system to combat tumors by restoring the immune response mediated by CD8+ cytotoxic T cells. Despite impressive clinical responses, most patients do not respond to ICIs. Therapeutic vaccines with autologous professional antigen-presenting cells, including dendritic cells, do not show yet significant clinical benefit. To improve these approaches, we have developed a new therapeutic vaccine based on an allogeneic plasmacytoid dendritic cell line (PDC*line), which efficiently activates the CD8+ T-cell response in the context of melanoma. The goal of the study is to demonstrate the potential of this platform to activate circulating tumor-specific CD8+ T cells in patients with lung cancer, specifically non-small-cell lung cancer (NSCLC). PDC*line cells loaded with peptides derived from tumor antigens are used to stimulate the peripheral blood mononuclear cells of NSCLC patients. Very interestingly, we demonstrate an efficient activation of specific T cells for at least two tumor antigens in 69% of patients irrespective of tumor antigen mRNA overexpression and NSCLC subtype. We also show, for the first time, that the antitumor CD8+ T-cell expansion is considerably improved by clinical-grade anti-PD-1 antibodies. Using PDC*line cells as an antigen presentation platform, we show that circulating antitumor CD8+ T cells from lung cancer patients can be activated, and we demonstrate the synergistic effect of anti-PD-1 on this expansion. These results are encouraging for the development of a PDC*line-based vaccine in NSCLC patients, especially in combination with ICIs.

Acetylation and phosphorylation of SRSF2 control cell fate decision in response to cisplatin.

SRSF2 is a serine/arginine-rich protein belonging to the family of SR proteins that are crucial regulators of constitutive and alternative pre-mRNA splicing. Although it is well known that phosphorylation inside RS domain controls activity of SR proteins, other post-translational modifications regulating SRSF2 functions have not been described to date. In this study, we provide the first evidence that the acetyltransferase Tip60 acetylates SRSF2 on its lysine 52 residue inside the RNA recognition motif, and promotes its proteasomal degradation. We also demonstrate that the deacetylase HDAC6 counters this acetylation and acts as a positive regulator of SRSF2 protein level. In addition, we show that Tip60 downregulates SRSF2 phosphorylation by inhibiting the nuclear translocation of both SRPK1 and SRPK2 kinases. Finally, we demonstrate that this acetylation/phosphorylation signalling network controls SRSF2 accumulation as well as caspase-8 pre-mRNA splicing in response to cisplatin and determines whether cells undergo apoptosis or G(2)/M cell cycle arrest. Taken together, these results unravel lysine acetylation as a crucial post-translational modification regulating SRSF2 protein level and activity in response to genotoxic stress.

Circulating free DNA concentration is an independent prognostic biomarker in lung cancer.

Plasma circulating cell-free (cf)DNA is of interest in oncology because it has been shown to contain tumour DNA and may thus be used as liquid biopsy. In nonsmall cell lung cancer (NSCLC), cfDNA quantification has been proposed for the monitoring and follow-up of patients. However, available studies are limited and need to be confirmed by studies with larger sample sizes and including patients who receive more homogenous treatments. Our objective was to assess the predictive and prognostic value of plasma cfDNA concentration in a large series of patients with NSCLC and treated with a standard chemotherapy regimen.We included samples from lung cancer patients recruited into the Pharmacogenoscan study. The cfDNA of 218 patients was extracted and quantified by fluorometry before and after two or three cycles of platinum-based chemotherapy. The association between baseline and post-chemotherapy concentrations and treatment response, assessed by RECIST (response evaluation criteria in solid tumours) or patient survival was analysed.Patients with high cfDNA concentrations (highest tertile) at baseline had a significantly worse disease-free and overall survival than those with lower concentrations (lowest and middle tertiles) (median overall survival 10 months (95% CI 10.7-13.9) versus 14.2 months (95% CI 12.6-15.8), respectively; p=0.001). In multivariate analysis, increased baseline concentration of cfDNA was an independent prognostic factor. However, we did not find any association between cfDNA concentration and response to treatment.cfDNA may be a biomarker for the assessment of prognosis in NSCLC. However, total concentration of cfDNA does not appear to predict chemotherapy response.

Evaluation of RECIST in chemotherapy-treated lung cancer: the Pharmacogenoscan Study.

BACKGROUND: Response Evaluation Criteria in Solid Tumors (RECIST) are widely used to assess the effect of chemotherapy in patients with cancer. We hypothesised that the change in unidimensional tumour size handled as a continuous variable was more reliable than RECIST in predicting overall survival (OS). METHODS: The prospective Pharmacogenoscan study enrolled consecutive patients with non-small-cell lung cancer (NSCLC) at any stage seen between 2005 and 2010 at six hospitals in France, given chemotherapy. After exclusion of patients without RECIST or continuous-scale tumour size data and of those with early death, 464 patients were left for the survival analyses. Cox models were built to assess relationships between RECIST 1.1 categories or change in continuous-scale tumour size and OS. The best model was defined as the model minimising the Akaike Information Criterion (AIC). RESULTS: OS was 14.2 months (IQR, 7.3-28.9 months). According to RECIST 1.1, 146 (31%) patients had a partial or complete response, 245 (53%) stable disease, and 73 (16%) disease progression. RECIST 1.1 predicted better OS than continuous-scale tumour in early (<6 months) predicted survival analyses (p = 0.03) but the accuracy of the two response evaluation methods was similar in late (≥6 months) predicted survival analyses (p = 0.15). CONCLUSION: In this large observational study, change in continuous-scale tumour size did not perform better than RECIST 1.1 in predicting survival of patients given chemotherapy to treat NSCLC. TRIAL REGISTRATION: NCT00222404.

Prognostic value of TP53, KRAS and EGFR mutations in nonsmall cell lung cancer: the EUELC cohort.

Nonsmall cell lung cancer samples from the European Early Lung Cancer biobank were analysed to assess the prognostic significance of mutations in the TP53, KRAS and EGFR genes. The series included 11 never-smokers, 86 former smokers, 152 current smokers and one patient without informed smoking status. There were 110 squamous cell carcinomas (SCCs), 133 adenocarcinomas (ADCs) and seven large cell carcinomas or mixed histologies. Expression of p53 was analysed by immunohistochemistry. DNA was extracted from frozen tumour tissues. TP53 mutations were detected in 48.8% of cases and were more frequent among SCCs than ADCs (p<0.0001). TP53 mutation status was not associated with prognosis. G to T transversions, known to be associated with smoking, were marginally more common among patients who developed a second primary lung cancer or recurrence/metastasis (progressive disease). EGFR mutations were almost exclusively found in never-smoking females (p=0.0067). KRAS mutations were detected in 18.5% of cases, mainly ADC (p<0.0001), and showed a tendency toward association with progressive disease status. These results suggest that mutations are good markers of different aetiologies and histopathological forms of lung cancers but have little prognostic value, with the exception of KRAS mutation, which may have a prognostic value in ADC.

Correcting for the influence of sampling conditions on biomarkers of exposure to phenols and phthalates: a 2-step standardization method based on regression residuals.

BACKGROUND: Environmental epidemiology and biomonitoring studies typically rely on biological samples to assay the concentration of non-persistent exposure biomarkers. Between-participant variations in sampling conditions of these biological samples constitute a potential source of exposure misclassification. Few studies attempted to correct biomarker levels for this error. We aimed to assess the influence of sampling conditions on concentrations of urinary biomarkers of select phenols and phthalates, two widely-produced families of chemicals, and to standardize biomarker concentrations on sampling conditions. METHODS: Urine samples were collected between 2002 and 2006 among 287 pregnant women from Eden and Pélagie cohorts, from which phthalates and phenols metabolites levels were assayed. We applied a 2-step standardization method based on regression residuals. First, the influence of sampling conditions (including sampling hour, duration of storage before freezing) and of creatinine levels on biomarker concentrations were characterized using adjusted linear regression models. In the second step, the model estimates were used to remove the variability in biomarker concentrations due to sampling conditions and to standardize concentrations as if all samples had been collected under the same conditions (e.g., same hour of urine collection). RESULTS: Sampling hour was associated with concentrations of several exposure biomarkers. After standardization for sampling conditions, median concentrations differed by--38% for 2,5-dichlorophenol to +80 % for a metabolite of diisodecyl phthalate. However, at the individual level, standardized biomarker levels were strongly correlated (correlation coefficients above 0.80) with unstandardized measures. CONCLUSIONS: Sampling conditions, such as sampling hour, should be systematically collected in biomarker-based studies, in particular when the biomarker half-life is short. The 2-step standardization method based on regression residuals that we proposed in order to limit the impact of heterogeneity in sampling conditions could be further tested in studies describing levels of biomarkers or their influence on health.

ING2 controls the progression of DNA replication forks to maintain genome stability.

Inhibitor of growth 2 (ING2) is a candidate tumour suppressor gene the expression of which is frequently lost in tumours. Here, we identified a new function for ING2 in the control of DNA replication and in the maintenance of genome stability. Global replication rate was markedly reduced during normal S-phase in small interfering RNA (siRNA) ING2 cells, as seen in a DNA fibre spreading experiment. Accordingly, we found that ING2 interacts with proliferating cell nuclear antigen and regulates its amount to the chromatin fraction, allowing normal replication progression and normal cell proliferation. Deregulation of DNA replication has been previously associated with genome instability. Hence, a high proportion of siRNA ING2 cells presented endoreduplication of their genome as well as an increased frequency of sister chromatid exchange. Thus, we propose for the first time that ING2 might function as a tumour suppressor gene by directly maintaining DNA integrity.

Fragile histidine triad gene inactivation in lung cancer: the European Early Lung Cancer project.

RATIONALE: Fragile histidine triad (FHIT) is a tumor suppressor gene involved in the pathogenesis of lung cancer. OBJECTIVES: The purpose of this study was to investigate the different molecular alterations leading to the inactivation of FHIT gene function and to validate their use as biomarkers of risk for progression of the disease in patients belonging to the multicentric European study for the Early detection of Lung Cancer (EUELC) who were resected for early-stage lung tumors. METHODS: FHIT immunostaining was performed on 305 tumor samples. The methylation status of FHIT promoter was assessed by nested methylation-specific polymerase chain reaction (MSP-PCR) in 232 tumor and 225 normal lung samples of which a subset of 187 patients had available normal/tumor DNA pairs. Loss of heterozygosity (LOH) at the FHIT locus was analyzed in 202 informative cases by D3S1300 and D3S1234 microsatellite markers. MEASUREMENTS AND MAIN RESULTS: Lost or reduced FHIT expression was found in 36.7 and 75.7% of the tumor samples, respectively. Methylation of the FHIT promoter was found in 36.7% of tumor and 32.7% of normal lung samples, whereas LOH was detected in 61.9% of the tumors. A strong association with complete loss of FHIT expression was present when methylation and LOH were analyzed together (P = 0.0064). Loss of FHIT protein expression was significantly more frequent in squamous cell carcinoma histotype (P < 0.0001) and in smokers (P = 0.008). FHIT methylation in normal lung was associated with an increased risk of progressive disease (OR, 2.27; P = 0.0415). CONCLUSIONS: Our results indicate that different molecular mechanisms interplay to inactivate FHIT expression and support the proposition that FHIT methylation in normal lung tissue could represent a prognostic marker for progressive disease.

Loss of histone H4K20 trimethylation occurs in preneoplasia and influences prognosis of non-small cell lung cancer.

PURPOSE: Epigenetic modifications of histone have crucial roles in the control of gene activity, nuclear architecture, and genomic stability. In this respect, they may contribute to the development and progression of cancer. We investigated whether epigenetic changes of histone H4 are involved in lung carcinogenesis. EXPERIMENTAL DESIGN: Epigenetic modifications of histone H4 were studied by immunohistochemistry in normal lung and 157 lung carcinoma using antibodies specifically recognizing the acetylated (Ac) lysines 5 (K5), K8, K12, K16, and trimethylated (me3) K20 residues of histone H4. Western blotting was used to validate the immunohistochemistry results. H4K20me3 was also studied in 17 preneoplastic lesions. Expression of the Suv4-20h1/2 trimethyltransferases was analyzed by quantitative reverse transcription-PCR in a subset of tumor samples. RESULTS: As compared with normal lung, cancer cells displayed an aberrant pattern of histone H4 modifications with hyperacetylation of H4K5/H4K8, hypoacetylation of H4K12/H4K16, and loss of H4K20 trimethylation. Alteration of H4K20 trimethylation was frequent in squamous cell carcinoma (67%) and was observed in early precursors lesions in which the level of H4K20me3 staining strongly decreased with disease progression. In adenocarcinoma, the down-regulation of H4K20me3 was less frequent (28%) but allowed the identification of a subgroup of stage I adenocarcinoma patients with reduced survival (P = 0.007). Loss of H4K20 trimethylation was associated with decreased expression of Suv4-20h2, a specific H4K20 trimethyltransferase involved in telomere length maintenance. CONCLUSIONS: Our findings indicate an important role of histone H4 modifications in bronchial carcinogenesis and highlight H4K20me3 as a candidate biomarker for early detection of and therapeutic approaches to lung cancer.

VEGF165b, a splice variant of VEGF-A, promotes lung tumor progression and escape from anti-angiogenic therapies through a ß1 integrin/VEGFR autocrine loop.

Vascular endothelial growth factor-A (VEGF-A) is highly subjected to alternative pre-mRNA splicing that generates several splice variants. The VEGFxxx and VEGFxxxb families encode splice variants of VEGF-A that differ only at the level of six amino acids in their C-terminal part. The expression level of VEGFxxx splice variants and their function as pro-angiogenic factors during tumor neo-angiogenesis have been well-described. The role of VEGFxxxb isoforms is less well known, but they have been shown to inhibit VEGFxxx-mediated angiogenesis, while being partial or weak activators of VEGFR receptors in endothelial cells. On the opposite, their role on tumor cells expressing VEGFRs at their surface remains largely unknown. In this study, we find elevated levels of VEGF165b, the main VEGFxxxb isoform, in 36% of non-small cell lung carcinoma (NSCLC), mainly lung adenocarcinoma (46%), and show that a high VEGF165b/VEGF165 ratio correlates with the presence of lymph node metastases. At the molecular level, we demonstrate that VEGF165b stimulates proliferation and invasiveness of two lung tumor cell lines through a VEGFR/ß1 integrin loop. We further provide evidence that the isoform-specific knockdown of VEGF165b reduces tumor growth, demonstrating a tumor-promoting autocrine role for VEGF165b in lung cancer cells. Importantly, we show that bevacizumab, an anti-angiogenic compound used for the treatment of lung adenocarcinoma patients, increases the expression of VEGF165b and activates the invasive VEGFR/ß1 integrin loop. Overall, these data highlight an unexpected role of the VEGF165b splice variant in the progression of lung tumors and their response to anti-angiogenic therapies.

The new tumor suppressor genes ING: genomic structure and status in cancer.

The Inhibitor of Growth 1 (ING1) gene has been identified and characterized as a Type-II tumor suppressor gene (TSG). Subsequently, 4 additional members of the family were identified by homology search. ING proteins contain a nuclear localization sequence (NLS) and a plant homeo domain (PHD) finger motif in their C-terminus. These proteins are involved in numerous signaling pathways especially in 2 tumor suppressor pathways: apoptosis and senescence. In human tumors, several studies have shown that the expression of ING1 is frequently lost or downregulated. It occurs most frequently at the RNA level, and thus epigenetics mechanism could be involved. We summarize the current knowledge on ING proteins functions and their involvement in various signaling pathways. We also review the studies that have investigated the ING protein status in human tumors. The interest of ING proteins as biomarkers and their role in tumor initiation and progression is discussed.

CT-guided biopsy of nonresolving focal air space consolidation.

OBJECTIVES: To evaluate the diagnostic accuracy of percutaneous computed tomography (CT)-guided coaxial core needle biopsy in patients with nonresolving pulmonary focal air space consolidations and negative fiberoptic bronchoscopy results. METHODS: From 1997 to 2005, 23 patients (11 woman, 12 men; age range, 45 to 81 y; mean age, 66 y) presenting with nonresolving pneumonia persisting more than 8 weeks (mean, 22 wk; range, 8 to 40 wk) with negative fiberscopic results, underwent coaxial percutaneous biopsy using an automated core needle (18-gauge) under CT guidance. Histologic and bacteriologic evaluations were obtained. The final diagnosis was confirmed by surgical pathology, culture results, or clinical follow-up. RESULTS: Specimens adequate for histopathologic evaluations were obtained in 20 (87%) cases. Final diagnoses were lung cancer (n=15) and benign diseases (infectious pneumonia, 3; lipoid pneumonia, 1; Erdheim Chester disease: 1; and nonspecific chronic pneumonia, 3). Diagnostic yield of core needle biopsy was 78% (18 of 23). The sensitivity and specificity for malignancy were 87% and 100%, respectively. Immediate pneumothorax was present in 11 patients of cases, but only 2 patients required pleural drainage. DISCUSSION: CT-guided lung biopsy using a core needle biopsy provides a high degree of diagnostic accuracy and allows specific characterization of nonresolving pulmonary focal air space consolidation.

Integrative genomic profiling of large-cell neuroendocrine carcinomas reveals distinct subtypes of high-grade neuroendocrine lung tumors.

Pulmonary large-cell neuroendocrine carcinomas (LCNECs) have similarities with other lung cancers, but their precise relationship has remained unclear. Here we perform a comprehensive genomic (n = 60) and transcriptomic (n = 69) analysis of 75 LCNECs and identify two molecular subgroups: "type I LCNECs" with bi-allelic TP53 and STK11/KEAP1 alterations (37%), and "type II LCNECs" enriched for bi-allelic inactivation of TP53 and RB1 (42%). Despite sharing genomic alterations with adenocarcinomas and squamous cell carcinomas, no transcriptional relationship was found; instead LCNECs form distinct transcriptional subgroups with closest similarity to SCLC. While type I LCNECs and SCLCs exhibit a neuroendocrine profile with ASCL1high/DLL3high/NOTCHlow, type II LCNECs bear TP53 and RB1 alterations and differ from most SCLC tumors with reduced neuroendocrine markers, a pattern of ASCL1low/DLL3low/NOTCHhigh, and an upregulation of immune-related pathways. In conclusion, LCNECs comprise two molecularly defined subgroups, and distinguishing them from SCLC may allow stratified targeted treatment of high-grade neuroendocrine lung tumors.

Baseline results of the Depiscan study: a French randomized pilot trial of lung cancer screening comparing low dose CT scan (LDCT) and chest X-ray (CXR).

BACKGROUND: Lung cancer has the highest mortality-rate per cancer, with an overall 5-year survival <15%. Several non-randomized studies pointed out the high sensitivity of low dose computed tomography (LDCT) to detect early stage lung cancer. In France, Depiscan, a pilot RCT of LDCT versus chest X-ray (CXR), started on October 2002 to determine the feasibility of enrollment by general practitioners (GPs), investigations and diagnostic procedures by university hospital radiologists and multidisciplinary teams, data management by centralized clinical research assistants, and anticipate the future management of a large national trial. METHODS: GPs and occupational physicians (OPs) selected and enrolled 1000 subjects in 1 year. Eligible subjects were asymptomatic males or females aged 50-75 years with a current or former cigarette smoking history of >/=15 cigarettes per day for at least 20 years (former smokers having quit <15 years prior to enrollment). Based to randomization, annual LDCT or CXR screenings were planned at baseline and annually for 2 years. RESULTS: Between October 2002 and December 2004, 765 subjects were enrolled by 89 out of the 232 participating GPs and OPs. Complete clinical and imaging baseline data were available for 621 individuals out of the 765 enrolled, due to 144 noncompliant subjects who withdrew their consent. At least one nodule was detected in 152 out of 336 subjects (45.2%) in the LDCT screening, versus 21 out of 285 subjects (7.4%) in the CXR screening arm. Eight lung cancers were detected in the LDCT arm and one in the CXR arm. DISCUSSION: This pilot trial allows estimating that non-calcified nodules are 10 [6.36-17.07] times more often detected from LDCT than from CXR. However enrollment by GPs was more difficult than expected with 41% active investigators and a high rate (19%) of noncompliant patients. This experience speaks to the need for a high level of GPs formation and a large, coordinated clinical research team in such a trial. TRIAL REGISTRATION NUMBER: 02526.

Telomere shortening and telomerase reverse transcriptase expression in preinvasive bronchial lesions.

PURPOSE: Telomerase, a ribonucleoprotein complex whose activity is related to the expression of its catalytic subunit human telomerase reverse transcriptase (hTERT), restores telomere length in tumor cells and enables immortality after p53/Rb inactivation has been achieved. To determine the timing of hTERT derepression during bronchial carcinogenesis and its relationship with telomere shortening and the p53/Rb pathway alterations, we did an immunohistochemical and in situ hybridization study in preinvasive and invasive bronchial lesions. EXPERIMENTAL DESIGN: hTERT, P53, P16, cyclin D1, Bax-to-Bcl2 ratio, and Ki67 immunostainings were done in 106 preneoplastic lesions and in paired lung carcinoma and normal bronchial mucosae. Concomitantly, hTERT mRNA levels and qualitative telomere shortening were assessed by in situ hybridization and fluorescence in situ hybridization, respectively, in a subset of preneoplastic and neoplastic lesions. RESULTS: Telomerase was increasingly expressed from normal epithelium to squamous metaplasia, dysplasia, and carcinoma in situ, and decreased in invasive carcinoma (P < 0.0001), with a direct correlation between protein and mRNA levels of expression (P < 0.0001). hTERT expression was directly correlated with P53, Ki67, and Bcl2-to-Bax ratio, suggesting a coupling between telomerase reactivation, proliferation, and resistance to apoptosis. Telomere signals significantly decreased as early as squamous metaplasia and progressively increased over the spectrum of preneoplastic lesions. CONCLUSIONS: Telomere shortening represents an early genetic abnormality in bronchial carcinogenesis, preceding telomerase expression and p53/Rb inactivation, which predominate in high-grade preinvasive lesions.

Identification of Circulating Tumor DNA for the Early Detection of Small-cell Lung Cancer.

Circulating tumor DNA (ctDNA) is emerging as a key potential biomarker for post-diagnosis surveillance but it may also play a crucial role in the detection of pre-clinical cancer. Small-cell lung cancer (SCLC) is an excellent candidate for early detection given there are no successful therapeutic options for late-stage disease, and it displays almost universal inactivation of TP53. We assessed the presence of TP53 mutations in the cell-free DNA (cfDNA) extracted from the plasma of 51 SCLC cases and 123 non-cancer controls. We identified mutations using a pipeline specifically designed to accurately detect variants at very low fractions. We detected TP53 mutations in the cfDNA of 49% SCLC patients and 11.4% of non-cancer controls. When stratifying the 51 initial SCLC cases by stage, TP53 mutations were detected in the cfDNA of 35.7% early-stage and 54.1% late-stage SCLC patients. The results in the controls were further replicated in 10.8% of an independent series of 102 non-cancer controls. The detection of TP53 mutations in 11% of the 225 non-cancer controls suggests that somatic mutations in cfDNA among individuals without any cancer diagnosis is a common occurrence, and poses serious challenges for the development of ctDNA screening tests.

Mdm2 overexpression and p14(ARF) inactivation are two mutually exclusive events in primary human lung tumors.

Pathways involving p53 and pRb tumor suppressor genes are frequently deregulated during lung carcinogenesis. Through its location at the interface of these pathways, Mdm2 can modulate the function of both p53 and pRb genes. We have examined here the pattern of expression of Mdm2 in a series of 192 human lung carcinomas of all histological types using both immunohistochemical and Western blot analyses and four distinct antibodies mapping different epitopes onto the Mdm2 protein. Using Immunohistochemistry (IHC), Mdm2 was overexpressed as compared to normal lung in 31% (60 out of 192) of all tumors analysed, whatever their histological types. Western blotting was performed on 28 out of the 192 tumoral samples. Overexpression of p85/90, p74/76 and p57 Mdm2 isoforms was detected in 18% (5 out of 28), 25% (7 out of 28) and 39% (11 out of 28) of the cases respectively. Overall, overexpression of at least one isoform was observed in 14 out of 28 (50%) lung tumors and concomittant overexpression of at least two isoforms in 7 out of 28 (25%) cases. A good concordance (82%) was observed between immunohistochemical and Western blot data. Interestingly, a highly significant inverse relationship was detected between p14(ARF) loss and Mdm2 overexpression either in NSCLC (P=0.0089) or in NE lung tumors (P<0.0001). Furthermore, a Mdm2/p14(ARF) >1 ratio was correlated with a high grade phenotype among NE tumors overexpressing Mdm2 (P=0.0021). Taken together, these data strongly suggest that p14(ARF)and Mdm2 act on common pathway(s) to regulate p53 and/or pRb-dependent or independent functions and that the Mdm2 : p14(ARF) ratio might act as a rheostat in modulating the activity of both proteins.

Value of immunohistochemical markers in preinvasive bronchial lesions in risk assessment of lung cancer.

PURPOSE: Bronchial carcinogenesis is a multistep process characterized by accumulation of genetic and molecular abnormalities, which precedes and accompanies the preinvasive lesions known as dysplasia and carcinoma in situ (CIS). We hypothesized that the level of accumulated molecular abnormalities in dysplasia assessed by immunohistochemical markers might reflect the severity of the carcinogenic process, thus allowing for risk assessment in smokers. EXPERIMENTAL DESIGN: We performed a prospective analysis of bronchial biopsies in 48 former smokers who had at least one area of metaplasia. Twenty-two of the patients had a previous history of lung cancer. Eighty bronchial lesions were recorded at baseline, including 31 metaplasia, 12 mild dysplasia, 9 moderate dysplasia, 9 severe dysplasia, and 19 CISs. Forty-one percent of the patients had multiple preinvasive lesions. Immunohistochemical analysis of P53, cyclin D1, cyclin E, Bax, and Bcl2 was performed. Aberrant expression of one of these proteins as compared with normal bronchi was recorded as one molecular alteration. RESULTS: After 18 months, 17 patients were diagnosed with lung cancer. No isolated parameter, including dysplastic grade or any isolated molecular alteration, was significantly associated with cancer occurrence at 18 months follow-up, using a logistic regression statistical analysis. In contrast, considering CIS and cancer as end point, more than two immunohistochemical abnormalities were associated with cancer or CIS occurrence (P = 0.02). CONCLUSIONS: We concluded that the cumulative index of immunohistochemical abnormalities in a random dysplasia is associated with CIS or lung cancer in the cancerization field of symptomatic smokers, independently of the histopathological grade of dysplasia. This set of histopathological biomarkers might be useful in risk assessment and provide intermediate end points for chemopreventive trials.