p63 immunoreactivity in lung cancer: yet another player in the development of squamous cell carcinomas?

Molecular Characterization of Esophageal Squamous Cell Carcinoma Using Quantitative Proteomics

Esophageal squamous cell carcinoma (ESCC) is a heterogeneous cancer associated with a poor prognosis in advanced stages. In India, it is the sixth most common cause of cancer-related mortality. In this study, we employed high-resolution mass spectrometry-based quantitative proteomics to characterize the differential protein expression pattern associated with ESCC. We identified several differentially expressed proteins including PDPN, TOP2A, POSTN and MMP2 that were overexpressed in ESCC. In addition, we identified downregulation of esophagus tissue-enriched proteins such as SLURP1, PADI1, CSTA, small proline-rich proteins such as SPRR3, SPRR2A, SPRR1A, KRT4, and KRT13, involved in squamous cell differentiation. We identified several overexpressed proteins mapped to the 3q24-29 chromosomal region, aligning with CNV alterations in this region reported in several published studies. Among these, we identified overexpression of SOX2, TP63, IGF2BP2 and RNF13 that are encoded by genes in the 3q26 region. Functional enrichment analysis revealed proteins involved in cell cycle pathways, DNA replication, spliceosome, and DNA repair pathways. We identified the overexpression of multiple proteins that play a major role in alleviating ER stress, including SYVN1 and SEL1L. The SYVN1/SEL1L complex is an essential part of the ER quality control machinery clearing misfolded proteins from the ER. SYVN1 is an E3 ubiquitin ligase that ubiquitinates ER-resident proteins. Interestingly, there are also other non-canonical substrates of SYVN1 which are known to play a crucial role in tumor progression. Thus, SYVN1 could be a potential therapeutic target in ESCC.

A Functional Polymorphism in Accessible Chromatin Region Confers Risk of Non-Small Cell Lung Cancer in Chinese Population

Background

The disease-associated non-coding variants identified by genome-wide association studies (GWASs) were enriched in open chromatin regions (OCRs) and implicated in gene regulation. Genetic variants in OCRs thus may exert regulatory functions and contribute to non-small cell lung cancer (NSCLC) susceptibility.

Objective

To fine map potential functional variants in GWAS loci that contribute to NSCLC predisposition using chromatin accessibility and histone modification data and explore their functions by population study and biochemical experimental analyses.

Methods

We mapped the chromatin accessible regions of lung tissues using data of assay for transposase-accessible chromatin using sequencing (ATAC-seq) in The Cancer Genome Atlas (TCGA) and prioritized potential regulatory variants within lung cancer GWAS loci by aligning with histone signatures using data of chromatin immunoprecipitation assays followed by sequencing (ChIP-seq) in the Encyclopedia of DNA Elements (ENCODE). A two-stage case–control study with 1,830 cases and 2,001 controls was conducted to explore the associations between candidate variants and NSCLC risk in Chinese population. Bioinformatic annotations and biochemical experiments were performed to further reveal the potential functions of significant variants.

Results

Sixteen potential functional single-nucleotide polymorphisms (SNPs) were selected as candidates from bioinformatics analyses. Three variants out of the 16 candidate SNPs survived after genotyping in stage 1 case–control study, and only the results of SNP rs13064999 were successfully validated in the analyses of stage 2 case–control study. In combined analyses, rs13064999 was significantly associated with NSCLC risk [additive model; odds ratio (OR) = 1.17; 95%CI, 1.07–1.29; p = 0.001]. Functional annotations indicated its potential enhancer bioactivity, and dual-luciferase reporter assays revealed a significant increase in luciferase activity for the reconstructed plasmid with rs13064999 A allele, when compared to the one with wild-type G allele (p_A549 < 0.001, p_SK-MES-1 = 0.004). Further electrophoretic mobility shift assays (EMSA) and super-shift assays confirmed a stronger affinity of HP1γ for the binding motif containing SNP rs13064999 A allele.

Conclusion

These findings suggested that the functional variant rs13064999, identified by the integration of ATAC-seq and ChIP-seq data, contributes to the susceptibility of NSCLC by affecting HP1γ binding, while the exact biological mechanism awaits further exploration.

Toxicity of Ortho-phthalaldehyde Aerosols in a Human In Vitro Airway Tissue Model

Ortho-phthalaldehyde (OPA) is a chemical disinfectant used for the high-level sterilization of heat-sensitive medical instruments. Although OPA is considered a safer alternative to glutaraldehyde, no exposure limits have been established for respiratory exposures to ensure the safety of OPA sterilization and the safe use of OPA-treated medical instruments. In order to address data gaps in the toxicological profile of OPA, we treated human in vitro air-liquid-interface (ALI) airway cultures at the air interface with various concentrations of OPA aerosols for 10 consecutive days. Temporal tissue responses were evaluated at multiple time points during the treatment phase as well as 10 days following the last exposure. The disturbance of glutathione (GSH) homeostasis occurred as early as 20 min following the first exposure, while oxidative stress persisted throughout the treatment phase, as indicated by the sustained induction of heme oxygenase-1 (HMOX-1) expression. Repeated exposures to OPA aerosols resulted in both functional and structural changes, including the inhibition of ciliary beating frequency, aberrant mucin production, decreases in airway secretory cells, and tissue morphological changes. While OPA-induced oxidative stress recovered to control levels after a 10 day recovery period, functional and structural alterations caused by the high concentration of OPA aerosols failed to fully recover over the observation period. These findings indicate that aerosolized OPA induces both transient and relatively persistent functional and structural abnormalities in ALI cultures under the conditions of the current study.

Lung squamous cell carcinoma and lung adenocarcinoma differential gene expression regulation through pathways of Notch, Hedgehog, Wnt, and ErbB signalling

Lung malignancies comprise lethal and aggressive tumours that remain the leading cancer-related death cause worldwide. Regarding histological classification, lung squamous cell carcinoma (LUSC) and adenocarcinoma (LUAD) account for the majority of cases. Surgical resection and various combinations of chemo- and radiation therapies are the golden standards in the treatment of lung cancers, although the five-year survival rate remains very poor. Notch, Hedgehog, Wnt and Erbb signalling are evolutionarily conserved pathways regulating pivotal cellular processes such as differentiation, proliferation, and angiogenesis during embryogenesis and post-natal life. However, to date, there is no study comprehensively revealing signalling networks of these four pathways in LUSC and LUAD. Therefore, the aim of the present study was the investigation profiles of downstream target genes of pathways that differ between LUSC and LUAD biology. Our results showed a few co-expression modules, identified through weighted gene co-expression network analysis (WGCNA), which significantly differentiated downstream signaling of Notch, ErbB, Hedgehog, and Wnt in LUSC and LUAD. Among co-expressed genes essential regulators of the cell cycle, DNA damage response, apoptosis, and proliferation have been found. Most of them were upregulated in LUSC compared to LUAD. In conclusion, identified downstream networks revealed distinct biological mechanisms underlying cancer development and progression in LUSC and LUAD that may diversify the clinical outcome of the disease.

Thyroid transcription factor 1 and p63 expression is associated with survival outcome in patients with non-small cell lung cancer treated with erlotinib

While erlotinib is primarily administered to patients with non-small cell lung cancer with sensitizing epidermal growth factor receptor (EGFR) mutations, it is also prescribed to patients with wild type (wt) EGFR in higher lines of treatment. However, there is no predictive marker for erlotinib efficacy in patients with EGFR wt. Certain immunohistochemical (IHC) parameters, including thyroid transcription factor 1 (TTF1) and p63, have been reported to indicate predictive power in patients with EGFR wt. The present study focused on retrospective data from the University Hospital in Pilsen using the TULUNG register. TTF1 and p63 expression data were extracted from the hospital information system and merged with registry data to calculate progression-free survival (PFS) and overall survival (OS) rates. A cohort of 345 patients with adenocarcinoma (ADC) or squamous cell carcinoma (SCC) exhibited similar erlotinib efficacies when TTF1 and p63 were ignored. However, significant differences were reported in PFS and OS rates of a subgroup of 126 patients where TTF1 and p63 parameters were known. In a univariate analysis, group A (ADC TTF1+/p63-) achieved PFS of 2.6 months, group B (SSC TTF1-/p63+) 1.9 months and group C (did not fit into groups A or B, i.e., ADC TTF1-/p63+ or SCC TTF1+/p63-) 1.4 months (P=0.006). Median OS was 14.2, 19.1 and 5.3 months for A, B and C, respectively (P=0.002). Furthermore, a multivariate analysis demonstrated IHC markers to be the only significant parameters for PFS and OS. Group C had a negative prognostic factor for PFS [hazard ratio (HR), 1.812; P=0.02] and OS (HR=2.367; P=0.01). In conclusion, patients with EGFR wt and lung carcinomas without TTF1 and p63 expression typical for ADC (TTF1+/p633-) or SCC (TTF1-/p63+) do not appear to be suitable candidates for erlotinib treatment.

TTF-1/p63-Positive Poorly Differentiated NSCLC: A Histogenetic Hypothesis from the Basal Reserve Cell of the Terminal Respiratory Unit

TTF-1 is expressed in the alveolar epithelium and in the basal cells of distal terminal bronchioles. It is considered the most sensitive and specific marker to define the adenocarcinoma arising from the terminal respiratory unit (TRU). TTF-1, CK7, CK5/6, p63 and p40 are useful for typifying the majority of non-small-cell lung cancers, with TTF and CK7 being typically expressed in adenocarcinomas and the latter three being expressed in squamous cell carcinoma. As tumors with coexpression of both TTF-1 and p63 in the same cells are rare, we describe different cases that coexpress them, suggesting a histogenetic hypothesis of their origin. We report 10 cases of poorly differentiated non-small-cell lung carcinoma (PD-NSCLC). Immunohistochemistry was performed by using TTF-1, p63, p40 (ΔNp63), CK5/6 and CK7. EGFR and BRAF gene mutational analysis was performed by using real-time PCR. All the cases showed coexpression of p63 and TTF-1. Six of them showing CK7+ and CK5/6− immunostaining were diagnosed as “TTF-1+ p63+ adenocarcinoma”. The other cases of PD-NSCLC, despite the positivity for CK5/6, were diagnosed as “adenocarcinoma, solid variant”, in keeping with the presence of TTF-1 expression and p40 negativity. A “wild type” genotype of EGFR was evidenced in all cases. TTF1 stained positively the alveolar epithelium and the basal reserve cells of TRU, with the latter also being positive for p63. The coexpression of p63 and TTF-1 could suggest the origin from the basal reserve cells of TRU and represent the capability to differentiate towards different histogenetic lines. More aggressive clinical and morphological features could characterize these “basal-type tumors” like those in the better known “basal-like” cancer of the breast.

Hyper-phosphorylation of Rb S249 together with CDK5R2/p39 overexpression are associated with impaired cell adhesion and epithelial-to-mesenchymal transition: Implications as a potential lung cancer grading and staging biomarker

Prediction of lung cancer metastasis relies on post-resection assessment of tumor histology, which is a severe limitation since only a minority of lung cancer patients are diagnosed with resectable disease. Therefore, characterization of metastasis-predicting biomarkers in pre-resection small biopsy specimens is urgently needed. Here we report a biomarker consisting of the phosphorylation of the retinoblastoma protein (Rb) on serine 249 combined with elevated p39 expression. This biomarker correlates with epithelial-to-mesenchymal transition traits in non-small cell lung carcinoma (NSCLC) cells. Immunohistochemistry staining of NSCLC tumor microarrays showed that strong phospho-Rb S249 staining positively correlated with tumor grade specifically in the squamous cell carcinoma (SCC) subtype. Strong immunoreactivity for p39 positively correlated with tumor stage, lymph node invasion, and distant metastases, also in SCC. Linear regression analyses showed that the combined scoring for phospho-Rb S249, p39 and E-cadherin in SCC is even more accurate at predicting tumor staging, relative to each score individually. We propose that combined immunohistochemistry staining of NSCLC samples for Rb phosphorylation on S249, p39, and E-cadherin protein expression could aid in the assessment of tumor staging and metastatic potential when tested in small primary tumor biopsies. The intense staining for phospho-Rb S249 that we observed in high grade SCC could also aid in the precise sub-classification of poorly differentiated SCCs.

Application of Immunohistochemistry in the Diagnosis of Pulmonary and Pleural Neoplasms

CONTEXT

- A vast majority of neoplasms arising from lung or pleura are initially diagnosed based on the histologic evaluation of small transbronchial, endobronchial, or needle core biopsies. Although most diagnoses can be determined by morphology alone, immunohistochemistry can be a valuable diagnostic tool in the workup of problematic cases.

OBJECTIVE

- To provide a practical approach in the interpretation and immunohistochemical selection of lung/pleura-based neoplasms obtained from small biopsy samples.

DATA SOURCES

- A literature review of previously published articles and the personal experience of the authors were used in this review article.

CONCLUSION

- Immunohistochemistry is a useful diagnostic tool in the workup of small biopsies from the lung and pleura sampled by small biopsy techniques.

TERT promoter mutation status in sarcomatoid urothelial carcinomas of the upper urinary tract

AIM

To determine TERT promoter mutation status as well as the expression of PAX8, GATA3, p63, p40, p53 and uroplakin III in 17 patients with the upper urinary tract sarcomatoid urothelial carcinoma.

METHODS & RESULTS

 TERT C228T mutations were found in six of 17 cases (35%). p53 was expressed in 77% of these tumors. PAX8, GATA3, p40 and uroplakin III are less frequently expressed. Lymph node metastases were present in ten cases (59%). Eight patients (47%), including all three patients with TERT mutation, died of cancer within 2 years after surgery.

CONCLUSION

Sarcomatoid carcinoma of the upper urinary tract is an aggressive tumor and the presence of TERT mutation may portend poor prognosis.

The Regulation of Tumor Suppressor p63 by the Ubiquitin-Proteasome System

The protein p63 has been identified as a homolog of the tumor suppressor protein p53 and is capable of inducing apoptosis, cell cycle arrest, or senescence. p63 has at least six isoforms, which can be divided into two major groups: the TAp63 variants that contain the N-terminal transactivation domain and the ΔNp63 variants that lack the N-terminal transactivation domain. The TAp63 variants are generally considered to be tumor suppressors involved in activating apoptosis and suppressing metastasis. ΔNp63 variants cannot induce apoptosis but can act as dominant negative inhibitors to block the function of TAp53, TAp73, and TAp63. p63 is rarely mutated in human tumors and is predominately regulated at the post-translational level by phosphorylation and ubiquitination. This review focuses primarily on regulation of p63 by the ubiquitin E-3 ligase family of enzymes via ubiquitination and proteasome-mediated degradation, and introduces a new key regulator of the p63 protein.

The impact of immunohistochemistry on the classification of lung tumors

INTRODUCTION

To highlight the role of immunohistochemistry to lung cancer classification on the basis of existing guidelines and future perspectives.

AREAS COVERED

Four orienting key-issues were structured according to an extensive review on the English literature: a) cancer subtyping; b) best biomarkers and rules to follow; c) negative and positive profiling; d) suggestions towards an evidence-based proposal for lung cancer subtyping. A sparing material approach based on a limited number of specific markers is highly desirable. It includes p40 for squamous cell carcinoma ('no p40, no squamous'), TTF1 for adenocarcinoma, synaptophysin for neuroendocrine tumors and vimentin for sarcomatoid carcinoma. A close relationship between genotype and phenotype also supports a diagnostic role for negative profiles. Expert commentary: Highly specific and sensitive IHC markers according to positive and negative diagnostic algorithms seem appropriate for individual patients' lung cancer subtyping.

Role of FNAC, fluid specimens, and cell blocks for cytological diagnosis of lung cancer in the present era

Cytoblocks prepared from residual tissue fluids and fine-needle aspirations can be useful adjuncts to smears for establishing a more definitive cytopathologic diagnosis. These paraffin embedded cytoblocks have been popular since these can be handled like any other histologic specimen. Rapid on-site evaluation (ROSE) can help in attaining adequate material in the cytoblock, which is a major concern to the cytopathologists. Ancillary studies can be done using cytoblocks including IHC and various molecular techniques. The opportunities for cytopathologists to influence therapy, and uncover strategies in the complex field of lung cancer are exciting and limitless especially in the presence of an adequate cytoblock

Expressions of Thyroid Transcription Factor-1, Napsin A, p40, p63, CK5/6 and Desmocollin-3 in Non-Small Cell Lung Cancer, as Revealed by Imprint Cytology Using a Malinol-Based Cell-Transfer Technique

BACKGROUND

The introduction of new therapies has made it important to differentiate between adenocarcinoma and squamous cell carcinoma. To allow the use of various immunocytochemical stains on limited materials, we tried transferring cells from a given smear to multiple slides. Using touch-preparation samples of 215 surgically resected non-small cell lung carcinomas of confirmed histologic classification (adenocarcinoma,n = 101; squamous cell carcinoma,n = 114), we performed immunocytochemistry for thyroid transcription factor-1, napsin A, p40, p63, CK5/6 and desmocollin-3, and compared cytologic staining results with the corresponding resection.

METHODS

We examined: (a) the expressions of the above 6 antibodies on cells transferred from touch imprints of resected specimens, the extent of staining being considered positive if more than 5% of the area was stained, and (b) the sensitivity, specificity, positive predictive value and negative predictive value for each antibody.

RESULTS

The histologic corresponding rate with Papanicolaou staining was only 73%. Regarding the differentiation of adenocarcinoma from squamous cell carcinoma, the sensitivity and specificity for napsin A in adenocarcinoma were 80 and 97%, respectively, while those for p40 in squamous cell carcinoma were 84 and 98%, respectively.

CONCLUSION

The immunocytochemical expressions of napsin A and p40 in imprint cytology seem to be of great utility for the accurate histological differentiation of lung cancers.

What clinicians are asking pathologists when dealing with lung neuroendocrine neoplasms?

Lung neuroendocrine tumors (NET) are currently classified in resection specimens according to four histological categories, namely typical carcinoid (TC), atypical carcinoid (AC), large-cell neuroendocrine carcinoma (LCNEC) and small cell carcinoma (SCC). Diagnostic criteria have remained unchanged in the 2015 WHO classification, which has ratified the wide acceptance and popularity of such terminology in the pathologists׳ and clinicians׳ community. A unifying umbrella of NE morphology and differentiation has been recognized in lung NET, which has pushed to enter an unique box of invasive tumors along with diffuse idiopathic pulmonary NE cell hyperplasia (DIPNECH) as a pre-invasive lesion with a potential toward the development of carcinoids. However, uncertainties remain in the terminology of lung NET upon small samples, where Ki-67 antigen could play some role to avoid misdiagnosing carcinoids as high-grade NE tumors. Epidemiologic, clinical and genetic traits support a biological three-tier over a pathology four-tier model, according to which TC are low malignancy tumors, AC intermediate malignancy tumors and LCNEC/SCC high malignancy tumors with no significant differences in survival among them. Inconsistencies in diagnostic reproducibility, troubles in the therapy of AC and LCNEC, and limitations to histology within the same tumor category argue in favor of a global re-thinking of lung NET where a grading system could play a role. This review outlines three main key questions in the field of lung NET: (A) unbiased diagnoses, (B) the role of Ki-67 and tumor grading, and (C) management of predictive markers. Answers are still inconclusive, thus additional research is required to improve our understanding on lung NET.

Rationale for targeting the ErbB family of receptors in patients with advanced squamous cell carcinoma of the lung

Squamous cell carcinoma (SCC) of the lung represents around 30% of all non-small-cell lung cancers. Treatment options for nonsquamous histology have increased in recent years following the development of pemetrexed chemotherapy and the identification of activating EGFR mutations and ALK rearrangements as targets for effective noncytotoxic agents. By contrast, until recently the development of new therapies for SCC has lagged behind. However, the identification of important genetic events driving SCC, including a greater understanding of the role of the ErbB receptor family in SCC pathogenesis, as well as recent immunotherapy advances, have led to new treatment options for SCC.

Chromosomal rearrangements and copy number abnormalities of TP63 correlate with p63 protein expression in lung adenocarcinoma

The TP63 gene encodes a member of the p53 family of transcription factors. Although TP53 is a well-known tumor suppressor gene, the role of p63 in tumorigenesis is controversial. Our group recently identified novel chromosomal rearrangements involving TP63 in approximately 6% of peripheral T-cell lymphomas, which correlated with a p63+/p40- immunohistochemical profile. As a subset of lung adenocarcinomas are p63+/p40-, we undertook the current study to examine the presence of TP63 rearrangements and correlate with p63/p40 expression. Next-generation sequencing was used to identify genomic rearrangements of TP63 in 37 adenocarcinomas. Confirmatory fluorescence in-situ hybridization (FISH) using a break-apart probe to the TP63 gene region and immunohistochemistry for p63 and p40 were performed on adenocarcinomas with TP63 rearrangements identified by mate-pair sequencing. Immunohistochemistry for p63 and p40 was performed on 45 additional adenocarcinomas, and FISH was performed on all adenocarcinomas with p63 positivity. TP63 rearrangement was identified in two adenocarcinoma specimens from a single patient. The rearrangement resulted in a complex rearrangement of 3q that fused B3GALNT1 at the 3' intron to TP63. FISH confirmed the rearrangement in both tumors. Immunohistochemistry staining for p63 was diffuse (>80% cells+) and p40 was negative. Of the 44 additional adenocarcinomas, 13 (30%) showed p63 expression; p40 was negative in all cases. No case showed rearrangement of TP63 by a break-apart FISH. However, extra copies of the intact TP63 locus were seen in the p63-positive areas of all 12 cases, with copy numbers ranging from three to seven. We have identified a novel chromosomal rearrangement involving TP63 in a p63+/p40- lung adenocarcinoma. Break-apart FISH testing can be used to diagnose this finding. Immunohistochemistry for p63 was not specific for this rearrangement, as nearly 33% of adenocarcinomas expressed p63. Additional copies of the intact TP63 locus were also a common finding and correlated with immunohistochemistry positivity for p63.

A comprehensive immunohistochemistry algorithm for the histological subtyping of small biopsies obtained from non-small cell lung cancers

AIMS

Need for accurate histologic subtyping of non-small cell lung carcinomas (NSCLCs) is growing. IHC patterns may be ambiguous in some cases, rendering it difficult to determine subtypes.

METHODS AND RESULTS

Tissue microarrays composed of 184 resected NSCLCs were stained for TTF-1, Napsin A, CK7, p40, p63, CK5/6, and mucicarmine. TTF-1 and Napsin A were chosen as the most accurate adenocarcinoma (ADC) marker (ACM), and p40 as squamous cell carcinoma (SCC) marker (SCM). We then prospectively performed IHC using these markers (TTF-1, Napsin A, and p40) in a cohort of small NSCLC biopsies (n = 186) with ambiguous morphology. Of these biopsies, 82.8% (154/186) were classifiable into either ADC or SCC by applying '3-marker IHC panel'. Additional CK7, p63, and CK5/6 were applied in 30 biopsies with equivocal IHC patterns, including 18 ACM-/SCM- (double-negative) and 12 ACM+/SCM+ (double-positive) cases. Decision tree and support vector machine models revealed that TTF-1 was a critical single marker for ADC in double-positive cases (91.7% accuracy), whereas p63 and/or CK5/6 helped to subtype double-negative cases (72.2% accuracy).

CONCLUSIONS

We propose a novel comprehensive algorithm for subtyping NSCLCs using a 3-marker IHC panel and additional p63 and CK5/6 that would be useful for subtyping small NSCLC biopsies.

Potential utility of p63 expression in differential diagnosis of non-small-cell lung carcinoma and its effect on prognosis of the disease

BACKGROUND

P63 is a gene located in chromosome 3q27-29, which has been implicated in regulation of stem cell commitment and promotion of squamous differentiation in various tissues. The aim of this study was to investigate whether there was a correlation between p63 expression, differential diagnosis of lung carcinoma, and prognosis.

MATERIAL AND METHODS

Immunohistochemical expression of p63 in 62 lung carcinomas was investigated and mRNA analysis using RT-PCR method was done in 6 selected cases.

RESULTS

When cases were evaluated for p63 staining, 24 of 25 (96%) squamous cell carcinomas were strongly positive. Six of 20 adenocarcinomas (25%) and 1 (100%) large cell carcinoma (except neuroendocrine carcinoma) were mildly positive. p63 staining was statistically significant in favor of squamous cell carcinoma than other tumors (p<0.001). Forty percent of squamous cell carcinomas had squamous carcinoma in situ, whereas adenocarcinomas had none. There was a significant statistical difference between squamous cell carcinoma and adenocarcinoma (p=0.002). p63 was strongly positive in all of 12 squamous carcinoma in situ cases. In 6 cases where mRNA analysis was performed by RT-PCR method, DNp63 was strongly positive in 3 squamous cell carcinomas, mildly positive in 1 adenocarcinoma, and negative in 1 carcinoid tumor. TAp63 was strongly positive in non-tumoral lung tissue but negative in all tumors, except 1 squamous cell carcinoma.

CONCLUSIONS

Our data suggest that poorly differentiated squamous cell carcinoma had strong and widespread staining for immunohistochemical expression of p63. Therefore, p63 can be a useful marker in differentiating squamous cell carcinoma from poorly differentiated adenocarcinoma and squamous cell carcinoma from large cell neuroendocrine carcinoma.

A genetic variant in p63 (rs17506395) is associated with breast cancer susceptibility and prognosis

BACKGROUND

p63, homologous to p53, has been investigated to be involved in various aspects of tumorigenesis and cancer progression. Recently, we have identified a functional single nucleotide polymorphism (SNP) rs17506395 (T>G) in p63 which was associated with female reproduction and ovarian cancer development. The present study aimed to evaluate the association of rs17506395 genotypes with breast cancer susceptibility, clinicopathological characteristics and prognosis.

PATIENTS AND METHODS

TaqMan assay was used to genotype the rs17506395 polymorphism. The expression of p63 mRNA was determined by quantitative reverse-transcription PCR (qRT-PCR). Unconditional logistic regression and univariate Cox hazard regression analyses were performed to evaluate the association of rs17506395 with breast cancer susceptibility and prognosis respectively.

RESULTS

First, we found that breast tumors with TT genotype exhibited higher level of p63 mRNA compared with other genotypes in breast cancer tissues, indicating that rs17506395 may be a functional single nucleotide polymorphism in breast cancer. Further investigation revealed that the presence of TT genotype was statistically correlated with increased risk for breast cancer, compared with genotypes containing the G allele (GG and GT). Moreover, a significant association between rs17506395 polymorphism and age at diagnosis and status of hormone receptor was observed. Consistently, prognostic analysis showed that patients carrying TT genotype represent unfavorable survival, suggesting that TT genotype may be a biomarker for poor prognosis in breast cancer.

CONCLUSION

Our data suggest that rs17506395 polymorphism can function as a risk factor and prognostic indicator for breast cancer, whereas precise mechanism underlying the function of this polymorphism needs further investigation.

A comprehensive comparative analysis of the histomorphological features of ALK-rearranged lung adenocarcinoma based on driver oncogene mutations: frequent expression of epithelial-mesenchymal transition markers than other genotype

Molecular classification of lung cancer correlates well with histomorphological features. However, specific histomorphological features that differentiate anaplastic lymphoma kinase (ALK)-rearranged tumors from ALK-negative tumors have not been fully evaluated. Eighty ALK-rearranged and 213 ALK-negative (91 epidermal growth factor receptor-mutated; 29 K-ras-mutated; 93 triple-negative) resected lung adenocarcinomas were analyzed for several histomorphological parameters and histological subtype. ALK-rearranged tumors were associated with younger age at presentation, frequent nodal metastasis, and higher stage of disease at diagnosis. ALK-rearranged tumors were more likely to show a solid predominant pattern than ALK-negative tumors (43.8%; 35/80; p<0.001). Unlike ALK-negative tumors, a lepidic predominant pattern was not observed in ALK-rearranged tumors (p<0.001). In multivariate analysis, the most significant morphological features that distinguished ALK-rearranged tumors from ALK-negative tumors were cribriform formation (odds ratio [OR], 3.253; p = 0.028), presence of mucin-containing cells (OR, 4.899; p = 0.008), close relationship to adjacent bronchioles (OR, 5.361; p = 0.001), presence of psammoma bodies (OR, 4.026; p = 0.002), and a solid predominant pattern (OR, 13.685; p = 0.023). ALK-rearranged tumors exhibited invasive histomorphological features, aggressive behavior and frequent expression of epithelial-mesenchymal transition markers (loss of E-cadherin and expression of vimentin) compared with other genotype (p = 0.015). Spatial proximity between bronchus and ALK-rearranged tumors and frequent solid histologic subtype with p63 expression may cause diagnostic difficulties to differentiate squamous cell carcinoma in the small biopsy, whereas p40 was rarely expressed in ALK-rearranged adenocarcinoma. Knowledge of these features may improve the diagnostic accuracy and lead to a better understanding of the characteristic behavior of ALK-rearranged tumors.

Utilization of p40 (ΔNp63) with p63 and cytokeratin 5/6 immunohistochemistry in non-small cell lung carcinoma fine-needle aspiration biopsy

OBJECTIVE

Specific subclassification of pulmonary non-small cell carcinoma (NSCCA) is clinically necessary, and the aim of this study is to examine the utilization of p40 (ΔNp63) in fine-needle aspiration (FNA) biopsy for lung NSCCA.

STUDY DESIGN

Database files of the Washington University Medical Center were searched. Patients who underwent endobronchial ultrasound and CT FNA of a primary lung neoplasia were selected and immunohistochemistry (IHC) was performed. A panel of markers was utilized, including p40, p63, cytokeratin (CK) 5/6, thyroid transcription factor, and napsin.

RESULTS

One hundred patients were identified and comprised 38 squamous cell carcinomas (SCCA), 46 adenocarcinomas (AdCA), and 16 NSCCA. For SCCA, p40 was positive in 34/38 cases (89%) and negative in 4/38 cases (11%); p63 was positive in 33/38 cases (87%) and negative in 5/38 cases (13%); CK5/6 was positive in 38/38 cases. For AdCA cases, p40 was negative, p63 was positive in 2 cases (5%) and CK5/6 was negative in 43/46 cases (92%).

CONCLUSION

For NSCCA, p40 had 89% sensitivity and 100% specificity compared to p63 with 86% sensitivity and 96% specificity and CK5/6 with 100% sensitivity and 96% specificity. In the evaluation of FNA biopsy for pulmonary NSCCA, p40 is a useful IHC marker for neoplastic subclassification, with better specificity in comparison to p63.

Role of thyroid transcription factor-1 and P63 immunocytochemistry in cytologic typing of non-small cell lung carcinomas

PURPOSE

Evaluation of the value of thyroid transcription factor (TTF-1) and P63 in subtyping of non-small cell lung cancer in cytologic material.

PATIENTS AND METHODS

This is a retrospective study including 40 cases of primary lung lesions who underwent image guided FNAC from pulmonary nodules. The final histopathologic diagnosis was the gold standard. Cell blocks were stained with anti-TTF-1, and P63. Nuclear immunoreactivity for both markers was considered specific. Sensitivity, specificity, positive and negative predictive values, of the cytologic diagnosis and of the two markers, as well as the accuracy of the combined markers were calculated.

RESULTS

Cytomorphology achieved a sensitivity of 83.3%, specificity of 91%, PPV of 91%, and NPV of 83.3%, for the diagnosis of AC, and 91% sensitivity, 83.3% specificity, 83.3% PPV, and 91% NPV, for the diagnosis of SCC. The concordance between cytologic and histopathologic diagnoses of AC and SCC was 87%. TTF-1 achieved 87.5% sensitivity, 94.7% specificity, 95.5% PPV, and 85.7% NPV for AC, while P63 achieved 94.7% sensitivity, 95.8% specificity, 94.7% PPV, and 95.8% NPV for SCC. TTF-1 enhanced the sensitivity of cytomorphology for AC from 83.3% to 87.5%, and specificity from 91% to 94.7%. Similarly P63 enhanced the sensitivity for SCC from 91% to 94.7%, and specificity from 83.3% to 95.8%.

CONCLUSION

TTF-1 achieved moderate sensitivity, and high specificity in the diagnosis of AC, while P63 was highly sensitive and specific for the diagnosis of SCC. Immunocytochemistry raised the sensitivity and specificity of FNAC in diagnosing AC and SCC using TTF-1 and P63, respectively.

Delineating Molecular Mechanisms of Squamous Tissue Homeostasis and Neoplasia: Focus on p63

Mouse models have informed us that p63 is critical for normal epidermal development and homeostasis. The p53/p63/p73 family is expressed as multiple protein isoforms due to a combination of alternative promoter usage and C-terminal alternative splicing. These isoforms can mimic or interfere with one another, and their balance ultimately determines biological outcome in a context-dependent manner. While not frequently mutated, p63, and in particular the ΔNp63 subclass, is commonly overexpressed in human squamous cell cancers. In vitro keratinocytes and murine transgenic and transplantation models have been invaluable in elucidating the contribution of altered p63 levels to cancer development, and studies have identified the roles for ΔNp63 isoforms in keratinocyte survival and malignant progression, likely due in part to their transcriptional regulatory function. These findings can be extended to human cancers; for example, the novel recognition of NFκB/c-Rel as a downstream effector of p63 has identified a role for NFκB/c-Rel in human squamous cell cancers. These models will be critical in enhancing the understanding of the specific molecular mechanisms of cancer development and progression.

ΔNp63 (p40) distribution inside lung cancer: a driver biomarker approach to tumor characterization

ΔNp63 (henceforth simply p40) is a squamous/basal-type biomarker corresponding to nontransactivating (non-TA) isoforms of p63 gene. Its prospective relevance as driver biomarker in lung cancer has not yet been thoroughly investigated. In all, 72 adenocarcinomas (ADs), 27 squamous cell carcinomas (SQCs), 13 pleomorphic carcinomas (PLCs), 10 small-cell lung carcinomas (SCLCs), 5 large-cell neuroendocrine carcinomas (LCNECs), 5 adenosquamous carcinomas (ADSQCs), 3 large-cell carcinomas with basaloid features (B-LCC), 2 carcinoids, 2 carcinosarcomas (CS), 2 salivary-gland type tumors (SGTTs) of the lung, and 5 pleural malignant epithelioid mesotheliomas (MEMs) were prospectively diagnosed by morphology and verified by immunohistochemistry for p40, p63, and thyroid transcription factor 1 (TTF1). Histological scores (HS) were devised by multiplying the percentage of immunoreactive cells (0 to 100%) by immunostaining intensity (low = 1 vs strong = 2, according to internal controls). There was a nonrandom distribution of p40 across the diverse tumor groups and cell differentiation lineages, with p40-HS > 100 closely paralleling squamous or myoepithelial carcinomas (SQC, B-LCC, SQC-containing PLC, ADSQC with predominant SQC, SGTT), and p40-HS ≤ 10 pinpointing AD, AD-containing PLC, or CS and neuroendocrine (NE) tumors. At variance, p63-HS was significantly higher than p40 in AD (P < .0001) and NE tumors (P = .0156), with positive predictive value being 83% and 95% and overall accuracy being 95% and 99%, respectively. Also, TTF1 was shared by gland-differentiated and NE tumors. MEM cases were always negative for all biomarkers. The HS-guided assessment of p40 allowed an effective orientation among thoracic malignancies at the level of individual tumor patients thereby contributing to prospectively realize a driver, holistic approach to cancer characterization.

Immunohistochemistry: applications to the evaluation of lung and pleural neoplasms: part 1

Immunohistochemistry has come to occupy a key position among the armamentarium of tools pathologists apply to the evaluation of lung and pleural neoplasms. This technique uses antibodies that bind to specific antigens, usually proteins, enabling microscopic detection of the antigens. Over the last several decades, an impressive array of antibodies has become commercially available, and many of these antibodies have become integrated into the routine practice of pathology. Evaluation of tissue or cytology samples with these antibodies can facilitate determination of tumor type and site of origin. Comments citing results of immunohistochemical staining with these antibodies frequently appear in pathology reports and may be difficult to translate for those less familiar with the technique. This review presents, in two parts, common diagnostic applications of immunohistochemistry, with information about strategies taken for frequently encountered differential diagnostic scenarios. This, the first of two parts, offers a basic overview of the technique and discusses its applications in the diagnosis of common primary lung carcinomas.

Association of RASSF1A and p63 with poor recurrence-free survival in node-negative stage I-II non-small cell lung cancer

PURPOSE

This study was aimed at analyzing the recurrence-related prognostic significance of 12 candidate molecular biomarkers in node-negative stage I-II non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

We retrospectively analyzed promoter methylation of eight genes using methylation-specific PCR in formalin-fixed and paraffin-embedded tissues from 328 node-negative stage I-II NSCLCs. The expression of Bcl-2, E-cadherin, p53, and p63 proteins was also assessed by immunohistochemistry.

RESULTS

Recurrence was found in 145 (44%) of 328 node-negative stage I-II NSCLCs with a median follow-up period of 6.2 years. No association was found between recurrence and alteration of individual biomarker in univariate analysis. We defined recurrently divergent groups on the basis of recursive partitioning analyses for 12 biomarkers and found a significant association of co-alteration of RASSF1A and p63 with poor recurrence-free survival (RFS). Cox proportional hazards analysis showed that hypermethylation of RASSF1A and negative expression of p63 was associated with poor RFS [HR, 1.93; 95% confidence interval (CI), 1.13-5.47; P = 0.009] compared with those without co-alteration of RASSF1A and p63, after adjusting for age, adjuvant therapy, histology, and tumor size. Random forest classifier including RASSF1A and p63 showed best performance in the prediction of recurrence in node-negative stage I-II NSCLCs: area under receiver operator characteristic curve for random forest was 0.91 and error rate for the model was 17%.

CONCLUSION

The present study suggests that RASSF1A and p63 may be independent prognostic indicators for RFS in node-negative stage I-II NSCLCs.

Tissue-preserving antibody cocktails to differentiate primary squamous cell carcinoma, adenocarcinoma, and small cell carcinoma of lung

CONTEXT

With the availability of cell type-specific therapies, differentiating primary lung squamous cell carcinomas (SCCs) and adenocarcinomas (ACAs) has become important. The limitations of small sample size and the need to conserve tissue for additional molecular studies necessitate the use of sensitive and specific marker panels on a single slide.

OBJECTIVE

To distinguish SCC from ACA and small cell carcinoma (SmCC) of lung using 2 novel tissue-conserving cocktails.

DESIGN

We compared two antibody cocktails, desmoglein 3 + cytokeratin 5/napsin A and p40/thyroid transcription factor 1 (Biocare Medical, Concord, California) in diagnosing SCC and ACA of the lung on tissue microarray, cytology, and surgical specimens. Both lung and nonlung tissue were evaluated on an 1150-core tissue microarray that contained 200 lung cancers. A microarray of 35 SmCCs and 5 small cell SCCs was also evaluated.

RESULTS

A cocktail of desmoglein 3 + cytokeratin 5/napsin A provided diagnostic accuracy in lung cancers with a sensitivity and specificity of 100% in SCCs and a sensitivity of 86% and a specificity of 100% in ACAs. A p40/thyroid transcription factor 1 cocktail showed p40 to have a specificity of 92% and a sensitivity of 93% in SCCs, whereas thyroid transcription factor 1 had a specificity of 100% and a sensitivity of 77% in ACAs. Cell blocks of fine-needle aspiration cytology compared with corresponding surgical (n = 20) specimens displayed similar findings. The p40 was useful in differentiating bladder from prostate carcinoma with 88% sensitivity. Isolated carcinomas from nonlung tissues were desmoglein 3 + cytokeratin 5 positive. Napsin A was positive in 22% of renal tumors as previously observed. Both cocktails were excellent in differentiating SmCCs and small cell SCCs because none of the SmCCs stained with p40.

CONCLUSIONS

Both antibody cocktails are excellent in differentiating primary lung ACA from SCC, as well as excluding SmCC and ACAs from all other sites on small specimens. A cocktail of desmoglein 3 + cytokeratin 5/napsin A is slightly superior compared with p40/thyroid transcription factor 1 cocktail.

UBE4B: a promising regulatory molecule in neuronal death and survival

Neuronal survival and death of neurons are considered a fundamental mechanism in the regulation of the nervous system during early development of the system and in adulthood. Defects in this mechanism are highly problematic and are associated with many neurodegenerative diseases. Because neuronal programmed death is apoptotic in nature, indicating that apoptosis is a key regulatory process, the p53 family members (p53, p73, p63) act as checkpoints in neurons due to their role in apoptosis. The complexity of this system is due to the existence of different naturally occurring isoforms that have different functions from the wild types (WT), varying from apoptotic to anti-apoptotic effects. In this review, we focus on the role of UBE4B (known as Ube4b or Ufd2a in mouse), an E3/E4 ligase that triggers substrate polyubiquitination, as a master regulatory ligase associated with the p53 family WT proteins and isoforms in regulating neuronal survival. UBE4B is also associated with other pathways independent of the p53 family, such as polyglutamine aggregation and Wallerian degeneration, both of which are critical in neurodegenerative diseases. Many of the hypotheses presented here are gateways to understanding the programmed death/survival of neurons regulated by UBE4B in normal physiology, and a means of introducing potential therapeutic approaches with implications in treating several neurodegenerative diseases.

Lung cancer: a classic example of tumor escape and progression while providing opportunities for immunological intervention

Lung cancers remain one of the most common and deadly cancers in the world today (12.5% of newly diagnosed cancers) despite current advances in chemo- and radiation therapies. Often, by the time these tumors are diagnosed, they have already metastasized. These tumors demonstrate the classic hallmarks of cancer in that they have advanced defensive strategies allowing them to escape various standard oncological treatments. Immunotherapy is making inroads towards effectively treating other fatal cancers, such as melanoma, glioblastoma multiforme, and castrate-resistant prostate cancers. This paper will cover the escape mechanisms of bronchogenic lung cancer that must be overcome before they can be successfully treated. We also review the history of immunotherapy directed towards lung cancers.

ΔNp63 (p40) and thyroid transcription factor-1 immunoreactivity on small biopsies or cellblocks for typing non-small cell lung cancer: a novel two-hit, sparing-material approach

INTRODUCTION

Diagnosing non-small cell lung cancer on biopsy/cellblock samples by morphology may be demanding. As sparing material for molecular testing is mandatory, a minimalist immunohistochemistry (IHC)-based diagnostic approach is warranted by means of novel, reliable, and easy-to-assess biomarkers.

METHODS

Forty-six consecutive biopsy/cellblock samples and the corresponding resection specimens (as the gold standard for morphology and IHC) from 30 adenocarcinomas (AD), 10 squamous carcinomas (SQC), 5 adenosquamous carcinomas (ADSQC), and 1 sarcomatoid carcinoma (SC) were IHC-evaluated for p40 [corresponding to nontransactivating ΔNp63 isoforms] and thyroid transcription factor-1 (TTF1) by semiquantitative assessment. For p40, also immunodecoration intensity was taken into account and dichotomized as strong or low.

RESULTS

Nonrandom and overlapping distributions of the relevant markers were found in biopsy/cellblock and surgical specimens, which closely correlated with each other and the diverse tumor categories, with no differences in area under curve-receiver-operating-characteristic curves for each marker between any two samples, including p40 and p63. Diagnostic combinations were p40-/TTF1+ or TTF1- for AD (where p40 was negative, apart from 5/30 AD showing at the best 1-2% tumor cells with low intensity); p40+/TTF1- (p40 strong and by far higher than 50%) for SQC; and p40+/TTF1+ or p40+/TTF1- (p40 strong and less than 50%) for ADSQC. The single SC case was p40-/TTF1-, suggesting glandular lineage. Practically, 41/46 (89%) tumors were correctly classified by IHC on small samples, including 30 AD, 10 SQC, 1/5 ADSQC, and no SC. Underdiagnosis of ADSQC was actually because of sampling error of biopsies/cellblocks rather than insufficient biomarker robustness, whereas underdiagnosis of SC was really because of the failure of either marker to highlight epithelial-mesenchymal transition.

CONCLUSIONS

This minimalist IHC-based model of p40 and TTF1 on biopsy/cellblock samples was effective to correctly subtype most cases of lung cancer.

p40 (ΔNp63) is superior to p63 for the diagnosis of pulmonary squamous cell carcinoma

Immunohistochemistry has recently emerged as a powerful ancillary tool for differentiating lung adenocarcinoma and squamous cell carcinoma-a distinction with important therapeutic implications. Although the most frequently recommended squamous marker p63 is extremely sensitive, it suffers from low specificity due to its reactivity in a substantial proportion of lung adenocarcinomas and other tumor types, particularly lymphomas. p40 is a relatively unknown antibody that recognizes ΔNp63-a p63 isoform suggested to be highly specific for squamous/basal cells. Here we compared the standard p63 antibody (4A4) and p40 in a series of 470 tumors from the archives of Memorial Sloan-Kettering Cancer Center and The Johns Hopkins Hospital, which included lung squamous cell carcinomas (n=81), adenocarcinomas (n=237), and large cell lymphomas (n=152). The p63 was positive in 100% of squamous cell carcinomas, 31% of adenocarcinomas, and 54% of large cell lymphomas (sensitivity 100%, specificity 60%). In contrast, although p40 was also positive in 100% of squamous cell carcinomas, only 3% of adenocarcinomas, and none of large cell lymphomas had p40 labeling (sensitivity 100%, specificity 98%). The mean percentage of p63 versus p40-immunoreactive cells in squamous cell carcinomas was equivalent (97 vs 96%, respectively, P=0.73). Rare adenocarcinomas with p40 labeling had reactivity in no more than 5% of tumor cells, whereas the mean (range) of p63-positive cells in adenocarcinomas and lymphomas was 26% (1-90%) and 48% (2-100%), respectively. In summary, p40 is equivalent to p63 in sensitivity for squamous cell carcinoma, but it is markedly superior to p63 in specificity, which eliminates a potential pitfall of misinterpreting a p63-positive adenocarcinoma or unsuspected lymphoma as squamous cell carcinoma. These findings strongly support the routine use of p40 in place of p63 for the diagnosis of pulmonary squamous cell carcinoma.

The challenge of NSCLC diagnosis and predictive analysis on small samples. Practical approach of a working group

Until recently, the division of pulmonary carcinomas into small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) was adequate for therapy selection. Due to the emergence of new treatment options subtyping of NSCLC and predictive testing have become mandatory. A practical approach to the new requirements involving interaction between pulmonologist, oncologist and molecular pathology to optimize patient care is described. The diagnosis of lung cancer involves (i) the identification and complete classification of malignancy, (ii) immunohistochemistry is used to predict the likely NSCLC subtype (squamous cell vs. adenocarcinoma), as in small diagnostic samples specific subtyping is frequently on morphological grounds alone not feasible (NSCLC-NOS), (iii) molecular testing. To allow the extended diagnostic and predictive examination (i) tissue sampling should be maximized whenever feasible and deemed clinically safe, reducing the need for re-biopsy for additional studies and (ii) tissue handling, processing and sectioning should be optimized. Complex diagnostic algorithms are emerging, which will require close dialogue and understanding between pulmonologists and others who are closely involved in tissue acquisition, pathologists and oncologists who will ultimately, with the patient, make treatment decisions. Personalized medicine not only means the choice of treatment tailored to the individual patient, but also reflects the need to consider how investigative and diagnostic strategies must also be planned according to individual tumour characteristics.

Heterogeneity of large cell carcinoma of the lung: an immunophenotypic and miRNA-based analysis

Large cell carcinomas (LCCs) of the lung are heterogeneous and may be of different cell lineages. We analyzed 56 surgically resected lung tumors classified as LCC on the basis of pure morphologic grounds, using a panel of immunophenotypic markers (adenocarcinoma [ADC]-specific, thyroid transcription factor-1, cytokeratin 7, and napsin A; squamous cell carcinoma [SQCC]-specific, p63, cytokeratin 5, desmocollin 3, and Δnp63) and the quantitative analysis of microRNA-205 (microRNA sample score [mRSS]). Based on immunoprofiles 19 (34%) of the cases were reclassified as ADC and 14 (25%) as SQCC; 23 (41%) of the cases were unclassifiable. Of these 23 cases, 18 were classified as ADC and 5 as SQCC according to the mRSS. Our data show that an extended panel of immunohistochemical markers can reclassify around 60% of LCCs as ADC or SQCC. However, a relevant percentage of LCCs may escape convincing immunohistochemical classification, and mRSS could be used for further typing, but its clinical relevance needs further confirmation.

DeltaN TP63 reactivation, epithelial phenotype maintenance, and survival in lung squamous cell carcinoma

Genes, active during normal development, are frequently reactivated during neoplastic transformation and may be related to progression. One of them, the transcription factor TP63, is crucial for pulmonary epithelial development and a possible target of the recurrent 3q amplifications in lung squamous cell carcinoma (SCC). Here, we explored whether TP63 reactivation could be associated to cancer progression in lung SCC through an epithelial to mesenchymal transition. We studied TP63 amplification and TP63 expression at RNA and protein levels and we analyzed the ΔNTP63/TATP63 ratio that quantifies the proportion of the isoform lacking the transactivation domain/the isoform containing the transactivation domain. We correlated TP63 status to survival and to the expression of epithelial (E-cadherin and plakoglobin) and mesenchymal (N-cadherin, vimentin, TWIST1, and SNAIL) markers. We found that high ΔN/TA TP63 ratio was related to high E-cadherin and plakoglobin mRNA levels (P < 0.05) and that E-cadherin mRNA level was the only marker related to survival. Kaplan-Meier survival curves stratified according to the expression level of E-cadherin showed, as already reported in breast cancer, that patients with low (first quartile) or high (last quartile) E-cadherin expression had a worse survival with respect to patients with intermediate E-cadherin expression. Altogether, our results indicate that a reactivation of ΔNTP63 is linked to the maintenance of epithelial markers and suggest that E-cadherin has a dual role in lung SCC.

p53 Family: Role of Protein Isoforms in Human Cancer

TP53, TP63, and TP73 genes comprise the p53 family. Each gene produces protein isoforms through multiple mechanisms including extensive alternative mRNA splicing. Accumulating evidence shows that these isoforms play a critical role in the regulation of many biological processes in normal cells. Their abnormal expression contributes to tumorigenesis and has a profound effect on tumor response to curative therapy. This paper is an overview of isoform diversity in the p53 family and its role in cancer.

Immunohistochemical algorithm for differentiation of lung adenocarcinoma and squamous cell carcinoma based on large series of whole-tissue sections with validation in small specimens

Immunohistochemistry is increasingly utilized to differentiate lung adenocarcinoma and squamous cell carcinoma. However, detailed analysis of coexpression profiles of commonly used markers in large series of whole-tissue sections is lacking. Furthermore, the optimal diagnostic algorithm, particularly the minimal-marker combination, is not firmly established. We therefore studied whole-tissue sections of resected adenocarcinoma and squamous cell carcinoma (n=315) with markers commonly used to identify adenocarcinoma (TTF-1) and squamous cell carcinoma (p63, CK5/6, 34βE12), and prospectively validated the devised algorithm in morphologically unclassifiable small biopsy/cytology specimens (n=38). Analysis of whole-tissue sections showed that squamous cell carcinoma had a highly consistent immunoprofile (TTF-1-negative and p63/CK5/6/34βE12-diffuse) with only rare variation. In contrast, adenocarcinoma showed significant immunoheterogenetity for all 'squamous markers' (p63 (32%), CK5/6 (18%), 34βE12 (82%)) and TTF-1 (89%). As a single marker, only diffuse TTF-1 was specific for adenocarcinoma whereas none of the 'squamous markers,' even if diffuse, were entirely specific for squamous cell carcinoma. In contrast, coexpression profiles of TTF-1/p63 had only minimal overlap between adenocarcinoma and squamous cell carcinoma, and there was no overlap if CK5/6 was added as a third marker. An algorithm was devised in which TTF-1/p63 were used as the first-line panel, and CK5/6 was added for rare indeterminate cases. Prospective validation of this algorithm in small specimens showed 100% accuracy of adenocarcinoma vs squamous cell carcinoma prediction as determined by subsequent resection. In conclusion, although reactivity for 'squamous markers' is common in lung adenocarcinoma, a two-marker panel of TTF-1/p63 is sufficient for subtyping of the majority of tumors as adenocarcinomas vs squamous cell carcinoma, and addition of CK5/6 is needed in only a small subset of cases. This simple algorithm achieves excellent accuracy in small specimens while conserving the tissue for potential predictive marker testing, which is now an essential consideration in advanced lung cancer specimens.

Personalized medicine for lung cancer: new challenges for pathology

Recent advances in non-small-cell lung cancer (NSCLC) therapy mean the relatively simple discrimination between small-cell and 'non-small-cell' carcinoma is insufficient to determine the best treatment for individual patients. Safety, efficacy and prescribing requirements mandate more specific subtyping of NSCLC for several new drugs: practice made difficult by the tumour heterogeneity combined with the paucity of tissue in most diagnostic samples. Immunohistochemical approaches have emerged as accurate predictors of probable tumour histotype. P63 and/or cytokeratins 5 and 6 and thyroid transcription factor 1 (TTF1) are among the best predictors, respectively, of squamous and adenocarcinoma histology. Molecular characteristics may predict response to both newer molecular targeted agents and traditional cytotoxic agents. Specific mutations in the epidermal growth factor receptor (EGFR) gene as predictors of response to EGFR tyrosine kinase inhibitors (erlotinib, gefitinib) is the first example of markers which predict response to targeted agents. Actual drug targets [e.g. thymidilate synthase (TS) - pemetrexed] or markers of the tumour's ability to repair cytotoxic drug-induced damage [e.g. excision repair cross-complementation group 1 (ERCC1) - cisplatin] may well also complement NSCLC diagnosis. This extended diagnostic requirement from increasingly limited material provided by minimally invasive biopsy techniques poses major challenges for pathology.

Use of immunohistochemistry techniques in patients exposed to sulphur mustard gas

We performed a pathologic study with further using an immunohistochemical technique (using anti-p63 and anti-CK5) on tissues obtained by open lung biopsy from 18 patients with previous exposure to sulphur mustard (SM) as case group and 8 unexposed patients (control group). The most frequent pathologic diagnosis was constrictive bronchiolitis (44.4%), followed by respiratory (22.2%) and chronic cellular bronchiolitis (16.7%) in the case group, and hypersensitivity bronchiolitis (50%) in the control group. The pathologic diagnoses were significantly different in the case and control groups (P = 0.042). In slides stained by anti-p63 and anti-CK5, the percent of stained cells and the mean number of epithelial cells were lower in the case group in comparison to the control group. This difference was significant for the mean number of cells stained by anti-CK5 (P = 0.042). Furthermore, there was a significant correlation between pathologic diagnosis and total number of cells and mean number of cells stained with anti-p63 and anti-CK5 (P  value = 0.002, <0.001, 0.044). These results suggest that constrictive bronchiolitis may be the major pathologic consequence of exposure to SM. Moreover, decrease of p63 in respiratory tissues affected by SM may suggest the lack of regenerative capacity in these patients.

Role of p63 in cancer development

Since their initial identification p53 homologues p63 and p73 have been expected to play a role in cancer development due to their close homology to p53, notoriously one of the most mutated genes in cancer. However soon after their discovery the awareness that these genes were rarely mutated in cancer seemed to indicate that they did not play a role in its development. However a large number of data collected in the following years indicated that altered expression rather than mutation could be found in different neoplasia and play a role in its biology. In particular p63 due to its fundamental role in epithelial development seems to play a role in a number of tumors of epithelial origin. In this review we summarize some of the evidence linking p63 to carcinogenesis.

Evaluation of p53, p63, p21, p27, ki-67 in paranasal sinus squamous cell carcinoma and inverted papilloma

Using a molecular genetic approach, we try to confirm the molecular alterations of inverted papilloma and clarify its status as a putative precursor lesion of sinonasal squamous cell carcinoma. To better understand its genetics, we investigated the immunohistochemical protein expression patterns of cell-cycle-regulators p53, p63, p21, p27 and proliferation marker Ki-67 in 22 inverted papilloma and 9 squamous cell carcinoma of the sinonasal tract. Significantly elevated levels of p53 and p63 in squamous cell carcinoma of sinonasal tract compared with inverted papilloma were revealed. Ki-67-stained neoplastic cell nuclei were found in a significantly higher percentage of squamous cell carcinoma of sinonasal tract than in inverted papilloma, whereas no variation of p21 and p27 expression was identified. This work first examined the immunohistochemical overexpression of p63 in sinonasal inverted papilloma and squamous cell carcinoma. In conclusion, this is a first study shedding light on the expression of p63 in tumors of paranasal sinuses.

Combined double CK5/P63 stain: useful adjunct test for diagnosing pulmonary squamous cell carcinoma

Increasing demand for accurate differentiation of pulmonary squamous cell carcinoma (SQCC) from other subtypes can be challenging for pathologists. This is more so in fine-needle aspirations (FNA) since the sample is small and SQCC may show degenerative changes and necrosis that distort the cellular features. Immunohistochemistry (IHC) is a valuable adjunct, and CK5/6 and P63 immunoreactivity is found to be basically restricted to SQCC. In our study, we evaluated the efficiency of CK5/P63 double staining in the diagnosis of pulmonary SQCC in cell blocks (CB) of lung FNA. We used a cohort including 24 CB of lung SQCC and 34 CB of lung adenocarcinomas (ADC). IHC was performed for CK5/P63 double stain. Seventeen of 24 (70%) lung SQCC were positive for the double stain CK5/P63. Two (8%) were positive for CK5 alone and two (8%) were positive for P63 alone. Thus, a total 19 of 24(79%) SQCC of the lung were positive for CK5 and P63 each. In ADC, no immunoreactivity was detected for CK5 alone or combined CK5/P63. Three of 34(8%) ADC were positive for P63. This first study of double staining of CK5/P63 in FNA CB shows a sensitivity of 70% and specificity of 100% for SQCC of the lung. When each marker staining alone is included, the sensitivity for CK5 and P63 increases to 79% each. This double stain can help in the diagnosis of pulmonary SQCC with an accuracy of 88% and a positive predictive value of 100%.