Label-Free Quantitative Comparison of Cervical Mucus Peptides in Subjects With Endocervical Adenocarcinoma and Adenocarcinoma in Situ.

PURPOSE: To uncover potential diagnostic biomarkers for endocervical adenocarcinoma (EAC) and adenocarcinoma in situ (AIS). EXPERIMENTAL DESIGN: Quantitative label-free liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) peptidomics strategies were employed to profile 8 cervical mucus (CM) samples, including 3 EAC cases, 2 AIS cases and 3 normal controls (Ctrl). RESULTS: Among the 3721 exclusive peptides identified, 12 (5 up-regulated and 7 down-regulated) endogenous peptides were significantly expressed in EAC compared to healthy controls (EAC/Ctrl); 10 (7 up-regulated and 3 down-regulated) endogenous peptides were significantly expressed in AIS compared to healthy controls (AIS/Ctrl); 11 (6 up-regulated and 5 down-regulated) endogenous peptides were significantly expressed in EAC compared to AIS (EAC/AIS) (absolute fold change ≥1.5, Benjamini-Hochberg adjusted p-value ≤0.05). Among these identifications, annexin A1 (ANXA1) was found to be down-regulated both in EAC and AIS, and its unique peptide (FIENEEQEYVQTVK) may be promising indicators for cervical glandular epithelial lesions. CONCLUSION: This is the first study to utilize CM peptidomics in cervical glandular malignancies, which may reveal the novel noninvasive biomarkers for EAC and AIS.

A proteogenomic profile of early lung adenocarcinomas by protein co-expression network and genomic alteration analysis.

The tumourigenesis of early lung adenocarcinomas, including adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and lepidic predominant invasive adenocarcinoma (LPA), remains unclear. This study aimed to capture disease-related molecular networks characterising each subtype and tumorigenesis by assessing 14 lung adenocarcinomas (AIS, five; MIA, five; LPA, four). Protein-protein interaction networks significant to the three subtypes were elucidated by weighted gene co-expression network analysis and pairwise G-statistics based analysis. Pathway enrichment analysis for AIS involved extracellular matrix proteoglycans and neutrophil degranulation pathway relating to tumour growth and angiogenesis. Whereas no direct networks were found for MIA, proteins significant to MIA were involved in oncogenic transformation, epithelial-mesenchymal transition, and detoxification in the lung. LPA was associated with pathways of HSF1-mediated heat shock response regulation, DNA damage repair, cell cycle regulation, and mitosis. Genomic alteration analysis suggested that LPA had both somatic mutations with loss of function and copy number gains more frequent than MIA. Oncogenic drivers were detected in both MIA and LPA, and also LPA had a higher degree of copy number loss than MIA. Our findings may help identifying potential therapeutic targets and developing therapeutic strategies to improve patient outcomes.

The clinicopathological and molecular features of sporadic gastric foveolar type neoplasia.

Gastric intraepithelial foveolar type neoplasia (IEFN) is not well defined. In addition, atrophic mucosa (AM) is an important issue to consider when evaluating gastric tumorigenesis. Here, we assessed the clinicopathological characteristics and molecular alterations contributing to the development of IEFN compared with intestinal type neoplasia. We examined the clinicopathological and molecular features of 42 cases of IEFN with low-grade dysplasia (LGD) and those of 77 cases of intraepithelial intestinal type neoplasia (IEIN) with LGD. The clinicopathological and molecular features examined included the AM status, mucin phenotype expression, CDX2 expression, p53 overexpression, ß-catenin intranuclear accumulation, microsatellite instability (MSI), DNA methylation status (low methylation epigenotype [LME], intermediate ME, or high ME), allelic imbalances (AIs), and APC promoter 1B mutations. There were no differences in the frequencies of AM and rates of CDX2 expression between IEFN and IEIN cases. Although no differences in the frequencies of p53 overexpression and MSI were observed between the two histological types, intranuclear expression of ß-catenin was significantly higher in IEIN than in IEFN. In addition, although the rate of LME was significantly higher in IEFN cases than in IEIN cases, IEFN was characterized by AIs at multiple foci. Finally, mutation of the APC promoter 1B, which is a characteristic of gastric adenocarcinoma and proximal polyposis of the stomach (potentially resembling IEFN), was detected in only one IEFN case. These findings suggested that IEFN may be an independent entity in terms of molecular alterations including the presence of multiple AIs and LME.

Ciliogenesis and Hedgehog signalling are suppressed downstream of KRAS during acinar-ductal metaplasia in mouse.

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related deaths worldwide, but has a 5-year survival rate of only 7% primarily due to late diagnosis and ineffective therapies. To treat or even prevent PDAC, it is vital that we understand the initiating events that lead to tumour onset. PDAC develops from preneoplastic lesions, most commonly pancreatic intraepithelial neoplasias (PanINs), driven by constitutive activation of KRAS. In patients, PanINs are associated with regions of acinar-to-ductal metaplasia (ADM) where, in response to inflammation, acini dedifferentiate to a pancreatic progenitor-like fate. In healthy tissue this process is reversible leading to regeneration of the pancreas; however, in the presence of oncogenic KRAS, regeneration is blocked and ADM can give rise to PanIN lesions. Here, we used a 3D mouse acinar culture that recapitulates ADM in vitro to explore how KRAS prevents regeneration. Regeneration is regulated by Hedgehog (Hh) signalling, which is transduced via the primary cilium. In wild-type acini, cilia assemble upon ADM and Hh target gene expression is upregulated; however, ciliogenesis and Hh signalling are suppressed during ADM in cells expressing oncogenic KRAS. We show that ciliogenesis fails due to ectopic activation of the cilium disassembly pathway, which is mediated by AurkA, a direct transcriptional target of KRAS. Inhibition of AurkA is able to rescue primary cilia and restore Hh signalling. We suggest that this could be used as a mechanism to prevent the formation of early lesions and thereby prevent progression to PDAC.

SOX17 expression and its down-regulation by promoter methylation in cervical adenocarcinoma in situ and adenocarcinoma.

AIMS: SOX17 expression has not been studied in glandular lesions of the uterine cervix like adenocarcinoma in situ (AIS) and invasive adenocarcinomas (AdC), whereas SOX17 promoter CpG island methylation has been reported. Therefore, the aim of this study was to relate the topographical distribution of SOX17 expression and SOX17 methylation status to each other, and to SOX2 expression, human papillomavirus (HPV) type, and physical status of the virus. METHODS AND RESULTS: Immunohistochemistry was used in 45 cases to assess expression of SOX17 and SOX2. SOX17 promoter methylation was determined in 25 cases by means of bisulphite conversion and methylation-specific polymerase chain reaction. SOX17 and SOX2 showed a mutually exclusive expression pattern in normal epithelium, with a sharp delineation in the squamocolumnar junction. SOX17 was found in endocervical columnar and reserve cells, whereas SOX2 was exclusively found in squamous epithelium. In both glandular lesions and cases with coexisting glandular and squamous intraepithelial components, a complex combination of SOX17 and SOX2 expression patterns was seen and mutually exclusive expression was lost. Frequently, gain of expression of SOX2 was found and expression of SOX17 was lost. Methylation of the CpG island in the SOX17 promoter was shown to be strongly associated with loss of expression of SOX17 (P = 0.0016). CONCLUSIONS: In this study, we show for the first time a direct correlation between the topographical distribution of SOX17 expression and the methylation status of its gene promoter. This explains the heterogeneity of SOX17 expression in the glandular lesions of the cervix. No correlation was found between HPV type and physical status of the virus on the one hand and methylation status on the other.

ARID1A Maintains Differentiation of Pancreatic Ductal Cells and Inhibits Development of Pancreatic Ductal Adenocarcinoma in Mice.

BACKGROUND & AIMS: The ARID1A gene encodes a protein that is part of the large adenosine triphosphate (ATP)-dependent chromatin remodeling complex SWI/SNF and is frequently mutated in human pancreatic ductal adenocarcinomas (PDACs). We investigated the functions of ARID1A during formation of PDACs in mice. METHODS: We performed studies with Ptf1a-Cre;KrasG12D mice, which express activated Kras in the pancreas and develop pancreatic intraepithelial neoplasias (PanINs), as well as those with disruption of Aird1a (Ptf1a-Cre;KrasG12D;Arid1af/f mice) or disruption of Brg1 (encodes a catalytic ATPase of the SWI/SNF complex) (Ptf1a-Cre;KrasG12D; Brg1f/fmice). Pancreatic ductal cells (PDCs) were isolated from Arid1af/f mice and from Arid1af/f;SOX9OE mice, which overexpress human SOX9 upon infection with an adenovirus-expressing Cre recombinase. Pancreatic tissues were collected from all mice and analyzed by histology and immunohistochemistry; cells were isolated and grown in 2-dimensional and 3-dimensional cultures. We performed microarray analyses to compare gene expression patterns in intraductal papillary mucinous neoplasms (IPMNs) from the different strains of mice. We obtained 58 samples of IPMNs and 44 samples of PDACs from patients who underwent pancreatectomy in Japan and analyzed them by immunohistochemistry. RESULTS: Ptf1a-Cre;KrasG12D mice developed PanINs, whereas Ptf1a-Cre;KrasG12D;Arid1af/f mice developed IPMNs and PDACs; IPMNs originated from PDCs. ARID1A-deficient IPMNs did not express SOX9. ARID1A-deficient PDCs had reduced expression of SOX9 and dedifferentiated in culture. Overexpression of SOX9 in these cells allowed them to differentiate and prevented dilation of ducts. Among mice with pancreatic expression of activated Kras, those with disruption of Arid1a developed fewer PDACs from IPMNs than mice with disruption of Brg1. ARID1A-deficient IPMNs had reduced activity of the mTOR pathway. Human IPMN and PDAC specimens had reduced levels of ARID1A, SOX9, and phosphorylated S6 (a marker of mTOR pathway activation). Levels of ARID1A correlated with levels of SOX9 and phosphorylated S6. CONCLUSIONS: ARID1A regulates expression of SOX9, activation of the mTOR pathway, and differentiation of PDCs. ARID1A inhibits formation of PDACs from IPMNs in mice with pancreatic expression of activated KRAS and is down-regulated in IPMN and PDAC tissues from patients.

Tissue-based Immunohistochemical Biomarker Expression in Malignant Glandular Lesions of the Uterine Cervix: A Systematic Review.

Literature published between 1975 and 2015 was systematically reviewed to conduct a case-comparator study of tissue based, immunohistochemical biomarker expression among malignant glandular histotypes of the uterine cervix so as to identify differences that could have diagnostic utility. Of the 902 abstracts, 154 articles had a full review, and 52 were included. Biomarker positivity in cases of adenocarcinoma in situ (AIS) were compared with atypical lobular endocervical glandular hyperplasia and invasive histotypes grouped as mucinous, endometrioid, adenosquamous, serous clear cell, minimal deviation-gastric type, and mesonephric carcinomas (7 AIS case-comparators). The invasive histotypes were compared with each other (30 adenocarcinoma case-comparators). Biomarker positivity in all 37 case-comparators was calculated as weighted averages of histotype-specific estimates. Unsupervised hierarchical clustering examined differences in expression and were visualized via heatmaps and dendrograms. Of the 56 biomarkers tested, 1 or more of 15 showed a 50% or more difference in positive expression in 6 (86%) of the AIS and 21 (70%) of the adenocarcinoma case-comparators. There was no data on the comparison of serous clear cell to mesonephric carcinoma. AIS case-comparator biomarkers were HIK1083, alpha SMA, PAX8, VIL1, CEA, p53, p16, and CD10, and only alpha SMA had a difference of 100%. The adenocarcinoma case-comparator biomarkers were CEA, p53, Claudin18, HIK1083, p16, Calretinin, CD10, PR, Chromogranin, MUC6, Vimentin and p63, and none had a difference of 100%. Biomarker expression in the discrimination of AIS from invasive adenocarcinoma, and the invasive histotypes from each other is understudied. One or more of 15 biomarkers could have diagnostic utility.

Stress-Activated NRF2-MDM2 Cascade Controls Neoplastic Progression in Pancreas.

Despite expression of oncogenic KRAS, premalignant pancreatic intraepithelial neoplasia 1 (PanIN1) lesions rarely become fully malignant pancreatic ductal adenocarcinoma (PDAC). The molecular mechanisms through which established risk factors, such as chronic pancreatitis, acinar cell damage, and/or defective autophagy increase the likelihood of PDAC development are poorly understood. We show that accumulation of the autophagy substrate p62/SQSTM1 in stressed KrasG12D acinar cells is associated with PDAC development and maintenance of malignancy in human cells and mice. p62 accumulation promotes neoplastic progression by controlling the NRF2-mediated induction of MDM2, which acts through p53-dependent and -independent mechanisms to abrogate checkpoints that prevent conversion of differentiated acinar cells to proliferative ductal progenitors. MDM2 targeting may be useful for preventing PDAC development in high-risk individuals.

Quantitative assessment of pancreatic cancer precursor lesions in IHC-stained tissue with a tissue image analysis platform.

Tissue image analysis (tIA) is emerging as a powerful tool for quantifying biomarker expression and distribution in complex diseases and tissues. Pancreatic ductal adenocarcinoma (PDAC) develops in a highly complex and heterogeneous tissue environment and, generally, has a very poor prognosis. Early detection of PDAC is confounded by limited knowledge of the pre-neoplastic disease stages and limited methods to quantitatively assess disease heterogeneity. We sought to develop a tIA approach to assess the most common PDAC precursor lesions, pancreatic intraepithelial neoplasia (PanIN), in tissues from KrasLSL-G12D/+; Trp53LSL-R172H/+; Pdx-Cre (KPC) mice, a validated model of PDAC development. tIA profiling of training regions of PanIN and tumor microenvironment (TME) cells was utilized to guide identification of PanIN/TME tissue compartment stratification criteria. A custom CellMap algorithm implementing these criteria was applied to whole-slide images of KPC mice pancreata sections to quantify p53 and Ki-67 biomarker staining in each tissue compartment as a proof-of-concept for the algorithm platform. The algorithm robustly identified a higher percentage of p53-positive cells in PanIN lesions relative to the TME, whereas no difference was observed for Ki-67. Ki-67 expression was also quantified in a human pancreatic tissue sample available to demonstrate the translatability of the CellMap algorithm to human samples. Together, our data demonstrated the utility of CellMap to enable objective and quantitative assessments, across entire tissue sections, of PDAC precursor lesions in preclinical and clinical models of this disease to support efforts leading to novel insights into disease progression, diagnostic markers, and potential therapeutic targets.

Microenvironmental changes in the progression from adenocarcinoma in situ to minimally invasive adenocarcinoma and invasive lepidic predominant adenocarcinoma of the lung.

OBJECTIVES: Invasive lepidic predominant adenocarcinoma (LPA) of the lung is thought to progress in a stepwise fashion from adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA). The aim of this study was to investigate the microenvironmental changes during the development from AIS to LPA. MATERIALS AND METHODS: Clinicopathological characteristics of AIS (n=51), MIA (n=59), LPA smaller than 3cm (LPA-S, n=113), and LPA larger than 3cm (LPA-L, n=47) were analyzed. We then evaluated the expression levels of epithelial-mesenchymal transition (EMT)-related molecules (E-cadherin, S100A4), invasion-related molecules (laminin-5, ezrin), stem-cell-related molecules (ALDH-1), and growth factor receptors (c-Met, EGFR) in cancer cells of each group (n=20). The number of tumor-promoting stromal cells, including podoplanin-positive cancer-associated fibroblasts (PDPN+ CAFs), CD204-positive tumor-associated macrophages (CD204+ TAMs), and CD34+ microvessel cells, were also analyzed. RESULTS: No significant difference in these characteristics was found between LPA-S and LPA-L. Laminin-5 expression in the non-invasive carcinoma component of MIA was significantly higher than that of AIS (p<0.001). During the progression from MIA to LPA-S, the expression level of laminin-5 in the invasive carcinoma component was significantly elevated (p<0.01). Moreover, tumor-promoting stromal cells were more frequently recruited in the invasive area of LPA-S (PDPN+ CAFs; p<0.05, CD204+ TAMs; p<0.001, CD34+ microvessel; p<0.05). Ezrin expression in the invasive carcinoma component of LPA-L was significantly increased (p<0.05) compared to LPA-S; however, the number of tumor-promoting stromal cells were not different between these two groups. CONCLUSION: Our current results indicated that microenvironmental molecular changes occur during the progression from MIA to LPA-S and suggested that this process may play an important role in disease progression from AIS to LPA.

Stratified Mucin-Producing Intraepithelial Lesion of the Cervix: Subtle Features Not to Be Missed.

OBJECTIVES: Stratified mucin-producing intraepithelial lesion (SMILE) is an uncommon premalignant lesion of the uterine cervix. A detailed examination of preinvasive SMILE cases including a comparison of the cytologic features with usual-type adenocarcinoma in situ (AIS) and human papillomavirus (HPV) genotyping was performed. STUDY DESIGN: Excisions and preceding Papanicolaou (Pap) tests were retrieved from the files of 2 tertiary care centers. Histologic review estimated the lesional SMILE proportion. Pap tests were reviewed and assessed for architectural, cellular and background features. Cobas® HPV test was performed. RESULTS: 13 cases were identified. Mean/median patient age was 35/33 years (range 23-51 years). Concurrent high-grade squamous intraepithelial lesion was found in 10/13 (77%) and AIS in 8/13 (62%) cases. In 6 cases, SMILE was dominant (≥50%) and represented in 5/6 corresponding Pap tests. Cytology interpretations differed more often in the SMILE-dominant group (p < 0.05). SMILE and AIS had overlapping features. Feathering and prominent nucleoli were absent in SMILE. HPV DNA was detected in all 12 cases tested. HPV 18 was most common (7/12). Excisions with positive/suspicious margins were reported in 5/6 SMILE-dominant versus 3/7 nondominant cases. CONCLUSION: SMILE is best considered as an AIS variant for cytologic, etiologic and management purposes. Cytologic features overlap with AIS, but are more subtle and easily missed. HPV testing may play a role in facilitating SMILE detection.

Esplenosis: diagnóstico no invasivo de un gran imitador / Splenosis: non-invasive diagnosis of a great mimicker

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The ubiquitin ligase RNF43 downregulation increases membrane expression of frizzled receptor in pancreatic ductal adenocarcinoma.

RNF43 is a novel tumor suppressor protein and known to be expressed in a multitude of tissue and dysregulated in cancers of these organs including ovarian and colorectal tissues. RNF43 expression has been shown to be expressed in mutated forms in several pancreatic cell lines. RNF43, by virtue of being an ubiquitin ligase, has the potential to ubiquitinylate membrane receptors like frizzled that subserves sensing Wnt soluble signals at the cell membrane. Thus, normally, RNF43 downregulates Wnt signaling by removing frizzled receptor from the membrane. In the present study, the expression of the tumor suppressor RNF43 was examined in human patient samples of pancreatic ductal adenocarcinoma (PDAC). Reduced levels of expression of RNF43 in PDAC were demonstrated by Western blotting. We incorporated membrane biotinylation assay to examine the expression of frizzled6 receptor in the membrane and demonstrated that it is significantly increased in PDAC tissues. This may be responsible for enhanced Wnt/beta-catenin signaling and provides the first level of evidence of a possible role of this well-known pathway in pancreatic exocrine carcinogenesis. We have utilized appropriate controls to ensure the true positivity of the findings of the present study. The contribution of Wnt/beta-catenin/RNF43 pathway in pancreatic carcinogenesis may provide for utilization of pharmacologic resources for precision-based approaches to treat pancreatic ductal adenocarcinoma.

[Remodeling of angiogenesis and lymphangiogenesis in cervical cancer development].

Ability to stimulate angiogenesis/lymphangiogenesis is recognized as an inherent feature of cancer cells providing necessary conditions for their growth and dissemination. "Angiogenic switch" is one of the earliest consequences of malignant transformation that encompasses a great number of genes and triggers a complex set of signaling cascades in endothelial cells. The processes of tumor microvasculature development are closely connected to the steps of carcinogenesis (from benign lesions to invasive forms) and occur through multiple deviations from the norm. Analysis of expression of proangiogenic factors at successive steps of cervical cancer development (intraepithelial neoplasia, cancer in situ, microinvasive, and invasive cancer) enables to reconstruct the regulatory mechanisms of (lymph-)angiogenesis and to discriminate the most important components. This review presents detailed analysis of literature data on expression of the key regulators of angiogenesis in cervical intraepithelial neoplasia and cervical cancer. Their possible involvement in molecular mechanisms of neoplastic transformation of epithelial cells, as well as invasion and tumor metastasis is discussed. Correlation between expression of proangiogenic molecular factors and various clinicopathological parameters is considered, the potential of their use in molecular diagnostics and targeted therapy of cervical cancer is reviewed. Particular attention is paid to relatively poorly studied regulators of lymphangiogenesis and "non-VEGF dependent", or alternative, angiogenic pathways that constitute the prospect of future research in the field.

[Immunohistochemical evaluation of mutant p53 protein over-expression in non-mucinous adenocarcinoma in-situ and invasive adenocarcinoma, NOS of lung].

OBJECTIVE: To study the over-expression of mutant p53 protein in non-mucinous adenocarcinoma in-situ (NMAIS) and invasive adenocarcinoma, NOS of lung. METHODS: Immunohistochemical study for p53 protein was performed on 17 cases of NMAIS and 70 cases of invasive adenocarcinoma, NOS of lung. The difference in p53 over-expression between the two tumor subtypes was analyzed. RESULTS: The over-expression of mutant p53 protein was observed in 0 case (0%) of NMAIS and 37 cases (52.9%) of invasive adenocarcinoma, NOS of lung. The difference was of statistical significance (P = 0.000). CONCLUSION: Mutant p53 protein over-expression may play a role in the progression of NMAIS to invasive adenocarcinoma, NOS.

Stratified mucin-producing intraepithelial lesion (SMILE): report of a case series with associated pathological findings.

AIMS: Stratified mucin-producing intraepithelial lesion (SMILE) is an uncommon premalignant cervical lesion showing morphological overlap with cervical intraepithelial neoplasia (CIN) and adenocarcinoma in situ (AIS)/cervical glandular intraepithelial neoplasia. Given the limited literature on SMILE, we aimed to document its frequency and assess the associated pathology in a large series of cases. METHODS AND RESULTS: Over a 6-year period, we documented all cases of SMILE and the associated findings. SMILE was diagnosed in 69 specimens from 60 patients (50 loop excisions and 19 punch biopsy specimens), constituting 0.6% of cervical specimens. Overall, SMILE coexisted with high-grade CIN in 93% of cases, AIS in 42%, and a carcinoma in 10%. When SMILE was diagnosed on a cervical punch biopsy, there was high-grade CIN in the follow-up loop in most cases. SMILE was consistently diffusely p16-positive and IMP3-negative. CONCLUSIONS: Given the morphological overlap and significant association with high-grade CIN and AIS, we believe that SMILE is best regarded as a form of high-grade reserve cell dysplasia, probably arising from reserve or stem cells with the capacity for multidirectional differentiation. We recommend that management of SMILE should be as for AIS.

Identification of mRNAs and lincRNAs associated with lung cancer progression using next-generation RNA sequencing from laser micro-dissected archival FFPE tissue specimens.

OBJECTIVES: Adenocarcinoma in situ (AIS) is an intermediate step in the progression of normal lung tissue to invasive adenocarcinoma. However, molecular mechanisms underlying this progression remain to be fully elucidated due to challenges in obtaining fresh clinical samples for downstream analyses. Formalin fixation and paraffin embedding (FFPE) is a tissue preservation system widely used for long-term storage. Until recently, challenges in working with FFPE precluded using new RNA sequencing technologies (RNA-seq), which would help clarify key pathways in cancer progression. Also, isolation techniques including laser-capture micro-dissection provide the ability to select histopathologically distinct tissues, allowing researchers to study transcriptional variations between tightly juxtaposed cell and tissue types. MATERIALS AND METHODS: Utilizing these technologies and new alignment tools we examined differential expression of long intergenic non-coding RNAs (lincRNAs) and mRNAs across normal, AIS and invasive adenocarcinoma samples from six patients to identify possible markers of lung cancer progression. RESULTS: RNA extracted and sequenced from these 18 samples generated an average of 198 million reads per sample. After alignment and filtering, uniquely aligned reads represented an average 35% of the total reads. We detected differential expression of a number of lincRNAs and mRNAs when comparing normal to AIS, or AIS to invasive adenocarcinoma. Of these, 5 lincRNAs and 31 mRNAs were consistently up- or down-regulated from normal to AIS and more so to invasive carcinoma. We validated the up-regulation of two mRNAs and one lincRNA by RT-qPCR as proof of principle. CONCLUSION: Our findings indicate a potential role of not only mRNAs, but also lincRNAs in the progression to invasive adenocarcinoma. We anticipate that these findings will lay the groundwork for future experimental studies of candidate RNAs from FFPE to identify their functional roles in lung cancer.

Expression of CLDN1 and CLDN10 in lung adenocarcinoma in situ and invasive lepidic predominant adenocarcinoma.

BACKGROUND: Non-mucinous bronchioloalveolar carcinoma (BAC) is considered the early stage of lung adenocarcinoma and is classified as the lung adenocarcioma in situ (AIS) by the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society. This study was designed to investigate the gene expression differences between AIS (formerly non-mucinous BAC) and invasive lepidic predominant adenocarcinoma (LPA, formerly non-mucinous BAC pattern with >5 mm invasion, mixed type adenocarcinoma with BAC features) and to investigate the mechanism of the progression of lung adenocarcinoma in situ to invasive adenocarcinoma. METHODS: Gene expression analysis was performed by using Agilent 4 × 44 K Whole Human Genome Oligo Microarray on 10 fresh frozen tissue samples of AIS and LPA, respectively. Real time RT-PCR was used to validate the differential expression of 13 genes selected by cDNA microarray on fresh frozen tissue samples from 41 patients with lung adenocarcinoma and 4 genes were confirmed. These 4 genes were then validated by western blotting. Immunohistochemical staining for these validated genes was performed on formalin-fixed, paraffin-embedded tissue samples from 81 cases of lung adenocarcinomna. RESULTS: We identified a 13 gene expression signature by comparative analysis of gene expression. Expression of these genes strongly differed between AIS and LPA. Four genes (MMP-2, c-fos, claudin 1 (CLDN1) and claudin 10(CLDN10)) were correlated with the results of microarray and real time RT-PCR analyses for the gene-expression data in samples from 41 patients with lung adenocarcinoma. As confirmed by western blotting, the expression levels of MMP-2 and c-fos were higher in LPA than those in AIS; the expression levels of CLDN1 and CLDN10 in LPA were lower than those in AIS. Immunohistochemical staining for these genes in samples from 81 cases of lung adenocarcinoma demonstrated the expressions of CLDN1 and CLDN10 were correlated with overall survival of patients with lung adenocarcinoma. CONCLUSIONS: CLDN1 and CLDN10 may play important roles in the development of AIS to LPA. Overexpression of CLDN1 and CLDN10 indicates a favorable prognosis for overall survival in some patients with lung adenocarcinoma. Expression of CLDN10 may be regulated by the c-fos pathway.