Chromosomal aberrations of primary lung adenocarcinomas in nonsmokers

Integrative genomics identifies SHPRH as a tumor suppressor gene in lung adenocarcinoma that regulates DNA damage response

BACKGROUND

Identification of driver mutations and development of targeted therapies has considerably improved outcomes for lung cancer patients. However, significant limitations remain with the lack of identified drivers in a large subset of patients. Here, we aimed to assess the genomic landscape of lung adenocarcinomas (LUADs) from individuals without a history of tobacco use to reveal new genetic drivers of lung cancer.

METHODS

Integrative genomic analyses combining whole-exome sequencing, copy number, and mutational information for 83 LUAD tumors was performed and validated using external datasets to identify genetic variants with a predicted functional consequence and assess association with clinical outcomes. LUAD cell lines with alteration of identified candidates were used to functionally characterize tumor suppressive potential using a conditional expression system both in vitro and in vivo.

RESULTS

We identified 21 genes with evidence of positive selection, including 12 novel candidates that have yet to be characterized in LUAD. In particular, SNF2 Histone Linker PHD RING Helicase (SHPRH) was identified due to its frequency of biallelic disruption and location within the familial susceptibility locus on chromosome arm 6q. We found that low SHPRH mRNA expression is associated with poor survival outcomes in LUAD patients. Furthermore, we showed that re-expression of SHPRH in LUAD cell lines with inactivating alterations for SHPRH reduces their in vitro colony formation and tumor burden in vivo. Finally, we explored the biological pathways associated SHPRH inactivation and found an association with the tolerance of LUAD cells to DNA damage.

CONCLUSIONS

These data suggest that SHPRH is a tumor suppressor gene in LUAD, whereby its expression is associated with more favorable patient outcomes, reduced tumor and mutational burden, and may serve as a predictor of response to DNA damage. Thus, further exploration into the role of SHPRH in LUAD development may make it a valuable biomarker for predicting LUAD risk and prognosis.

PDRG1 predicts a poor prognosis and facilitates the proliferation and metastasis of colorectal cancer

OBJECTIVE

The incidence and mortality of colorectal cancer (CRC) is increasing yearly and CRC patients are becoming younger in global. Evidences have revealed the carcinogenic effect of p53 and DNA damage-regulated gene 1 (PDRG1) in several types of tumors. However, its biological function is yet to be investigated in CRC. This study aimed to unveil the prooncogenic role of PDRG1 in CRC.

METHODS

We detected the expression and clinical pathological features of PDRG1 in CRC tissues and paired non-tumor adjacent tissues. The biological role and molecular mechanism of PDRG1 in CRC were characterized through a range of in vitro and in vivo experiments and datasets analysis.

RESULT

We identified the significant up-regulated expression of PDRG1 both in CRC tissues and cell, and higher expression of PDRG1 was associated with worse clinicopathological stage and poorer survival outcome. Cox regression analysis revealed that PDRG1 is an independent prognostic factor for CRC patients. Silencing of PDRG1 significantly retarded CRC cell vitality, invasion and migration, induced cell apoptosis and G0/G1 phase arrest. PDRG1 knockdown also attenuated tumor growth and metastasis as evidencing in vivo experiment. The expression of p21 and apoptosis related protein was enhanced with the knockdown of PDRG1 while cell cycle protein was inhibited.

CONCLUSION

PDRG1 function as a novel oncogene and participate in malignant progression of CRC by regulating p21-mediated signal pathway, suggesting that it can serve as a valuable predictive biomarker for diagnosing of CRC patient and a promising target for therapy.

Partial EMT in Squamous Cell Carcinoma: A Snapshot

In the process of cancer EMT, some subgroups of cancer cells simultaneously exhibit both mesenchymal and epithelial characteristics, a phenomenon termed partial EMT (pEMT). pEMT is a plastic state in which cells coexpress epithelial and mesenchymal markers. In squamous cell carcinoma (SCC), pEMT is regulated, and the phenotype is maintained via the HIPPO pathway, NOTCH pathway and TGF-β pathways and by microRNAs, lncRNAs and the cancer microenvironment (CME); thus, SCC exhibits aggressive tumorigenic properties and high stemness, which leads collective migration and therapy resistance. Few studies have reported therapeutic interventions to address cells that have undergone pEMT, and this approach may be an effective way to inhibit the plasticity, drug resistance and metastatic potential of SCC.

SOX9 has distinct roles in the formation and progression of different non-small cell lung cancer histotypes

The transcription factor SOX9 is a key regulator of multiple developmental processes and is frequently re-expressed in non-small cell lung cancer (NSCLC). Its precise role in the progression of NSCLC histotypes has, however, remained elusive. We show that SOX9 expression relates to poor overall survival and invasive histopathology in human non-mucinous adenocarcinoma and is absent in murine early minimally invasive and low in human in situ adenocarcinoma. Interestingly, despite wide SOX9 expression across advanced NSCLC histotypes, its genetic deletion in the murine Kras^G12D ;Lkb1^fl/fl model selectively disrupted only the growth of papillary NSCLC, without affecting the initiation of precursor lesions or growth of mucinous or squamous tissue. Spatial tissue phenotyping indicated a requirement of SOX9 expression for the progression of surfactant protein C-expressing progenitor cells, which gave rise to papillary tumours. Intriguingly, while SOX9 expression was dispensable for squamous tissue formation, its loss in fact led to enhanced squamous tumour metastasis, which was associated with altered collagen IV deposition in the basement membrane. Our work therefore demonstrates histopathology-selective roles for SOX9 in NSCLC progression, namely as a promoter for papillary adenocarcinoma progression, but an opposing metastasis-suppressing role in squamous histotype tissue. This attests to a pleiotropic SOX9 function, linked to the cell of origin and microenvironmental tissue contexts. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

The inhibition of tumor protein p53 by microRNA-151a-3p induced cell proliferation, migration and invasion in nasopharyngeal carcinoma

A close relation between microRNA-151a-3p (miR-151a-3p) and nasopharyngeal carcinoma (NPC) has been reported, however, the molecular mechanism is still unclear. The aim of the present study was to explore the mechanism in the promotion of miR-151a-3p to NPC progression. The levels of miR-151-3p in several NPC cell lines were detected in order to screen an experimental cell line. MiR-151a-3p mimic and inhibitor were constructed and transfected into 5-8F cells and cell proliferation were detected by Cell Counting Kit-8 (CCK-8). The apoptosis rate, cell migration and invasion were determined by flow cytometry, wound healing and Transwell assays. The predicted target was further verified by luciferase reporter assay. Real-time quantification-PCR and Western blot were carried out for mRNA and protein level analysis. Tumor protein p53 was co-transfected to verify the functions of miR-151a-3p. The miR-151a-3p level in NPC tissues was much higher than that in adjacent tissues. After transfecting cells with miR-151a-3p mimic, the cell proliferation and patients' survival rate were much increased, and this was accompanied by the increase in B-cell lymphoma 2 (Bcl-2) and decreases in Bax and cleaved caspase-3 (P<0.01). Moreover, the migration rate and number of invaded cells were also remarkably increased, however, the miR-151a-3p inhibitor had opposite effects on the 5-8F cells. Noticeably, p53 was revealed as a potential target of miR-151a-3p. Co-transfection of P53 could partially reverse the promotive effects of miR-151a-3p on NPC cell progression. Our data indicated that blocking p53 expression and mediated signal pathways contribute to the positive effects of miR-151a-3p on NPC cell proliferation, migration and invasion.

miR-151-5p modulates APH1a expression to participate in contextual fear memory formation

Long-term memory formation requires gene expression and new protein synthesis. MicroRNAs (miRNAs), a family of small non-coding RNAs that inhibit target gene mRNA expression, are involved in new memory formation. In this study, elevated miR-151-5p (miR-151) levels were found to be responsible for hippocampal contextual fear memory formation. Using a luciferase reporter assay, we demonstrated that miR-151 targets APH1a, a protein that has been identified as a key factor in γ-secretase activity, namely APH1a. Blocking miR-151 can upregulate APH1a protein levels and subsequently impair hippocampal fear memory formation. These results indicate that miR-151 is involved in hippocampal contextual fear memory by inhibiting APH1a protein expression. This work provides novel evidence for the role of miRNAs in memory formation and demonstrates the implication of APH1a protein in miRNA processing in the adult brain.

Integrative Genomic Analyses Identifies GGA2 as a Cooperative Driver of EGFR-Mediated Lung Tumorigenesis

INTRODUCTION

Targeted therapies for lung adenocarcinoma (LUAD) have improved patient outcomes; however, drug resistance remains a major problem. One strategy to achieve durable response is to develop combination-based therapies that target both mutated oncogenes and key modifiers of oncogene-driven tumorigenesis. This is based on the premise that mutated oncogenes, although necessary, are not sufficient for malignant transformation. We aimed to uncover genetic alterations that cooperate with mutant EGFR during LUAD development.

METHODS

We performed integrative genomic analyses, combining copy number, gene expression and mutational information for over 500 LUAD tumors. Co-immunoprecipitation and Western blot analysis were performed in LUAD cell lines to confirm candidate interactions while RNA interference and gene overexpression were used for in vitro and in vivo functional assessment.

RESULTS

We identified frequent amplifications/deletions of chromosomal regions affecting the activity of genes specifically in the context of EGFR mutation, including amplification of the mutant EGFR allele and deletion of dual specificity phosphatase 4 (DUSP4), which have both previously been reported. In addition, we identified the novel amplification of a segment of chromosome arm 16p in mutant-EGFR tumors corresponding to increased expression of Golgi Associated, Gamma Adaptin Ear Containing, ARF Binding Protein 2 (GGA2), which functions in protein trafficking and sorting. We found that GGA2 interacts with EGFR, increases EGFR protein levels and modifies EGFR degradation after ligand stimulation. Furthermore, we show that overexpression of GGA2 enhances EGFR mediated transformation while GGA2 knockdown reduces the colony and tumor forming ability of EGFR mutant LUAD.

CONCLUSIONS

These data suggest that overexpression of GGA2 in LUAD tumors results in the accumulation of EGFR protein and increased EGFR signaling, which helps drive tumor progression. Thus, GGA2 plays a cooperative role with EGFR during LUAD development and is a potential therapeutic target for combination-based strategies in LUAD.

Smoker and non-smoker lung adenocarcinoma is characterized by distinct tumor immune microenvironments

Tobacco smoking causes DNA damages in epithelial cells and immune dysfunction in the lung, which collectively contribute to lung carcinogenesis and progression. However, potential mechanisms by which tumor-infiltrating immune cells contribute to lung cancer survival and their differential contributions in ever-smokers and never-smokers are not well studied. Here, we performed integrative analysis of 11 lung cancer gene-expression datasets, including 1,111 lung adenocarcinomas and 200 adjacent normal lung samples. Distinct pathways were altered in lung carcinogenesis in ever-smokers and never-smokers. Never-smoker patients had a better outcome than ever-smoker patients. We characterized compositional patterns of 21 types of immune cells in lung adenocarcinomas and revealed the complex association between immune cell composition and clinical outcomes. Interestingly, we found two subsets of immune cells, mast cells and CD4⁺ memory T cells, which had completely opposite associations with outcomes in resting and activated status. We further discovered that several chemokines and their associated receptors (e.g., CXCL11-CX3CR1 axis) were selectively altered in lung tumors in response to cigarette smoking and their abundances showed stronger correlation with fractions of these immune subsets in ever-smokers than never-smokers. The status switched from the resting to activated forms in mast cells and CD4⁺ memory T cells might manifest some important processes induced by cigarette smoking during tumor development and progression. Our findings suggested that aberrant activation of mast cells and CD4+ memory T cells plays crucial roles in cigarette smoking-induced immune dysfunction in the lung, which contributes to tumor development and progression.

Enhancer invasion shapes MYCN-dependent transcriptional amplification in neuroblastoma

Amplification of the locus encoding the oncogenic transcription factor MYCN is a defining feature of high-risk neuroblastoma. Here we present the first dynamic chromatin and transcriptional landscape of MYCN perturbation in neuroblastoma. At oncogenic levels, MYCN associates with E-box binding motifs in an affinity-dependent manner, binding to strong canonical E-boxes at promoters and invading abundant weaker non-canonical E-boxes clustered at enhancers. Loss of MYCN leads to a global reduction in transcription, which is most pronounced at MYCN target genes with the greatest enhancer occupancy. These highly occupied MYCN target genes show tissue-specific expression and are linked to poor patient survival. The activity of genes with MYCN-occupied enhancers is dependent on the tissue-specific transcription factor TWIST1, which co-occupies enhancers with MYCN and is required for MYCN-dependent proliferation. These data implicate tissue-specific enhancers in defining often highly tumor-specific 'MYC target gene signatures' and identify disruption of the MYCN enhancer regulatory axis as a promising therapeutic strategy in neuroblastoma.

Hormonal receptors in lung adenocarcinoma: expression and difference in outcome by sex

Background

Lung cancer seems to have different epidemiological, biomolecular and clinical characteristics in females than in males, with a better prognosis for women. The aim of the study is to determine gender differences in lung adenocarcinoma in terms of androgen (AR), estrogen (ER)α and progesterone (PgR) receptors expression and their impact on outcome.

Results

Overall survival was significantly better in ERα and in PgR positive lung adenocarcinoma patients (median survival 45 vs. 19 months).

Eight out of 62 patients showed positive expression of nuclear (n) AR and 18 of cytoplasmic (c) AR with a significantly better survival (49 vs. 19 and 45 vs. 19 months, respectively). There was a significant difference in survival between patients with vs. without c-AR expression (30 vs. 17 months). Finally, in the subgroup of women, median survival was greater in positive expression of c-AR than for women with negative c-AR (45 vs. 21 months).

Materials and Methods

We conducted an analysis on a cohort of 62 patients with advanced NSCLC treated at our institution. We investigated the immunohistochemical expression of n/c AR, ERα and PgR in 62 NSCLC and we correlated it with patients' clinic-pathologic characteristics and with prognosis.

Conclusions

Our results showed that the positive expression of one hormonal receptor could represent a prognostic factor.

Furthermore our study suggests that AR should become object of close examination in a larger series of lung adenocarcinoma patients, also for selection of the patients with best prognosis that can perform more chemotherapy lines.

Notch1 pathway-mediated microRNA-151-5p promotes gastric cancer progression

Gastric carcinoma is the third leading cause of lethal cancer worldwide. Previous studies showed that Notch1 receptor intracellular domain (N1IC), the activated form of Notch1 receptor, promotes gastric cancer progression. It has been demonstrated that a significant cross-talk interplays between Notch pathways and microRNAs (miRNAs) in controlling tumorigenesis. This study identified an intronic microRNA-151 (miR-151), which consists of two mature miRNAs, miR-151-3p and miR-151-5p, as a Notch1 receptor-induced miRNA in gastric cancer cells. Activation of Notch1 pathway enhanced expressions of miR-151 and its host gene, focal adhesion kinase (FAK), in gastric cancer cells. The levels of miR-151 in gastric cancer samples were higher than those of adjacent non-tumor samples. Activated Notch1 pathway induced CBF1-dependent FAK promoter activity. The ectopic expression of miR-151 promoted growth and progression of SC-M1 gastric cancer cells including cell viability and colony formation, migration, and invasion abilities. Activated Notch1 pathway could augment progression of gastric cancer cells through miR-151-5p and FAK. The mRNA levels of pluripotency genes, Nanog and SOX-2, tumorsphere formation ability, tumor growth, and lung metastasis of SC-M1 cells were elevated by activated Notch1 pathway through miR-151-5p. Furthermore, miR-151-5p could target 3′-untranslated region (3′-UTR) of p53 mRNA and down-regulate p53 level in SC-M1 cells. Mechanistically, Notch1/miR-151-5p axis contributed to progression of SC-M1 cells through down-regulation of p53 which in turn repressed FAK promoter activity. Taken together, these results suggest that Notch1 pathway and miR-151-5p interplay with p53 in a reciprocal regulation loop in controlling gastric carcinogenesis.

PDRG1 at the interface between intermediary metabolism and oncogenesis

PDRG1 is a small oncogenic protein of 133 residues. In normal human tissues, the p53 and DNA damage-regulated gene 1 (PDRG1) gene exhibits maximal expression in the testis and minimal levels in the liver. Increased expression has been detected in several tumor cells and in response to genotoxic stress. High-throughput studies identified the PDRG1 protein in a variety of macromolecular complexes involved in processes that are altered in cancer cells. For example, this oncogene has been found as part of the RNA polymerase II complex, the splicing machinery and nutrient sensing machinery, although its role in these complexes remains unclear. More recently, the PDRG1 protein was found as an interaction target for the catalytic subunits of methionine adenosyltransferases. These enzymes synthesize S-adenosylmethionine, the methyl donor for, among others, epigenetic methylations that occur on the DNA and histones. In fact, downregulation of S-adenosylmethionine synthesis is the first functional effect directly ascribed to PDRG1. The existence of global DNA hypomethylation, together with increased PDRG1 expression, in many tumor cells highlights the importance of this interaction as one of the putative underlying causes for cell transformation. Here, we will review the accumulated knowledge on this oncogene, emphasizing the numerous aspects that remain to be explored.

miR-151a induces partial EMT by regulating E-cadherin in NSCLC cells

miR-151a and its host gene, focal adhesion kinase, FAK, are located in a region of chromosome 8q that is frequently amplified in solid tumors, including lung cancer. Lung cancer is the leading cause of cancer deaths worldwide and metastasis remains the major challenge in battling lung cancer mortality. Here, we demonstrate that miR-151a is overexpressed in non-small cell lung cancer (NSCLC) patient specimens, as compared to healthy lung. In addition, miR-151a overexpression promotes proliferation, epithelial-to-mesenchymal transition (EMT) and induces tumor cell migration and invasion of NSCLC cells. Blocking miR-151a expression using anti-miR-151a approaches significantly reduced NCSLC cell proliferative and motility potential. Furthermore, we determined that miR-151a significantly regulates E-cadherin expression. Finally, functional rescue experiments determined that overexpression of E-cadherin in miR-151a NSCLC cell lines potently repressed miR-151a-induced partial EMT and cell migration of NSCLC cells. In conclusion, our findings suggest that miR-151a functions as an oncomiR in NSCLC by targeting E-cadherin mRNA and inducing proliferation, migration and partial EMT.

Cancer Cytogenetics: An Introduction

The Philadelphia chromosome was the first chromosomal abnormality discovered in cancer using the cytogenetics technique in 1960, and was consistently associated with chronic myeloid leukemia. Over the past five decades, innovative technical advances in the field of cancer cytogenetics have greatly enhanced the detection ability of chromosomal alterations, and have facilitated the research and diagnostic potential of chromosomal studies in neoplasms. These developments notwithstanding, chromosome analysis of a single cell is still the easiest way to delineate and understand the relationship between clonal evolution and disease progression of cancer cells. The use of advanced fluorescence in situ hybridization (FISH) techniques allows for the further identification of chromosomal alterations that are unresolved by the karyotyping method. It overcame many of the drawbacks of assessing the genetic alterations in cancer cells by karyotyping. Subsequently, the development of DNA microarray technologies provides a high-resolution view of the whole genome, which may add massive amounts of new information and opens the field of cancer cytogenomics. Strikingly, cancer cytogenetics does not only provide key information to improve the care of patients with malignancies, but also acts as a guide to identify the genes responsible for the development of these neoplastic states and has led to the emergence of molecularly targeted therapies in the field of personalized medicine.

CAS (CSE1L) signaling pathway in tumor progression and its potential as a biomarker and target for targeted therapy

CSE1L (chromosome segregation 1-like protein), also named as CAS (cellular apoptosis susceptibility protein), is highly expressed in most cancer types. CSE1L/CAS is a multiple functional protein that plays roles in apoptosis, cell survival, chromosome assembly, nucleocytoplasmic transport, microvesicle formation, and cancer metastasis; some of the functions are explicitly correlated. CSE1L is also a cancer serum biomarker. The phosphorylation of CAS is regulated by the extracellular signal-regulated kinase (ERK). The RAS/RAF/MAPK/ERK signaling pathways are the essential targets of most targeted cancer drugs, thus serum phosphorylated CSE1L may be a potential biomarker for monitoring drug resistance in targeted therapy. CSE1L can regulate Ras-induced ERK phosphorylation. CSE1L also regulates the expression and phosphorylation of CREB (cAMP response element binding protein) and MITF (microphthalmia-associated transcription factor) and is thus involved in the melanogenesis and progression of melanoma. CAS is an exosome/microvesicle membrane protein. Tumor cells consistently secrete microvesicles and tumor-derived microvesicles may be accumulated around tumors. Therefore, microvesicle membrane CSE1L may be a potential target for the development of high-efficacy antibody-drug conjugates (ADCs) for cancer therapy. This review will focus on CSE1L expression in cancers, its relationship to Ras/ERK and cAMP/PKA signaling pathways in melanoma development, its potential for the development of ADCs and tumor imaging reagents, and secretory phosphorylated CSE1L for monitoring the emergence of drug resistance in targeted cancer therapy.

Lung Cancer in Never Smokers

Lung cancer is predominantly associated with cigarette smoking; however, a substantial minority of patients with the disease have never smoked. In the US it is estimated there are 17,000-26,000 annual deaths from lung cancer in never smokers, which as a separate entity would be the seventh leading cause of cancer mortality. Controversy surrounds the question of whether or not the incidence of lung cancer in never-smokers is increasing, with more data to support this observation in Asia. There are several factors associated with an increased risk of developing lung cancer in never smokers including second hand smoke, indoor air pollution, occupational exposures, and genetic susceptibility among others. Adenocarcinoma is the most common histology of lung cancer in never smokers and in comparison to lung cancer in smokers appears less complex with a higher likelihood to have targetable driver mutations.

Vitamin D Signaling Modulators in Cancer Therapy

The antiproliferative and pro-apoptotic effects of 1α,25-dihydroxycholecalciferol (1,25(OH)2D3, 1,25D3, calcitriol) have been demonstrated in various tumor model systems in vitro and in vivo. However, limited antitumor effects of 1,25D3 have been observed in clinical trials. This may be attributed to a variety of factors including overexpression of the primary 1,25D3 degrading enzyme, CYP24A1, in tumors, which would lead to rapid local inactivation of 1,25D3. An alternative strategy for improving the antitumor activity of 1,25D3 involves the combination with a selective CYP24A1 inhibitor. The validity of this approach is supported by numerous preclinical investigations, which demonstrate that CYP24A1 inhibitors suppress 1,25D3 catabolism in tumor cells and increase the effects of 1,25D3 on gene expression and cell growth. Studies are now required to determine whether selective CYP24A1 inhibitors+1,25D3 can be used safely and effectively in patients. CYP24A1 inhibitors plus 1,25D3 can cause dose-limiting toxicity of vitamin D (hypercalcemia) in some patients. Dexamethasone significantly reduces 1,25D3-mediated hypercalcemia and enhances the antitumor activity of 1,25D3, increases VDR-ligand binding, and increases VDR protein expression. Efforts to dissect the mechanisms responsible for CYP24A1 overexpression and combinational effect of 1,25D3/dexamethasone in tumors are underway. Understanding the cross talk between vitamin D receptor (VDR) and glucocorticoid receptor (GR) signaling axes is of crucial importance to the design of new therapies that include 1,25D3 and dexamethasone. Insights gained from these studies are expected to yield novel strategies to improve the efficacy of 1,25D3 treatment.

microRNA-151-3p regulates slow muscle gene expression by targeting ATP2a2 in skeletal muscle cells

MicroRNAs (miRNAs) are a group of small noncoding RNAs that regulate the stability or translation of cognate mRNAs at the post-transcriptional level. Accumulating evidence indicates that miRNAs play important roles in many aspects of muscle function, including muscle growth and development, regeneration, contractility, and muscle fiber type plasticity. In the current study, we examined the function of miR-151-3p in myoblast proliferation and differentiation. Results show that overexpression of miR-151-3p not only upregulates myoblast proliferation, but also decreases slow muscle gene expression (such as MHC-β/slow and slow muscle troponin I) in both C2C12 myotubes and in primary cultures. Alternatively, inhibition of miR-151-3p by antisense RNA was found to upregulate MHC-β/slow expression, indicating that miR-151-3p plays a role in muscle fiber type determination. Further investigation into the underlying mechanisms revealed for the first time that miR-151-3p directly targets ATP2a2, a gene encoding for a slow skeletal and cardiac muscle specific Ca(2+) ATPase, SERCA2 thus downregulating slow muscle gene expression. Mechanisms by which the alteration in SERCA2 expression induces changes in other slow muscle gene expression levels needs to be defined in future research.

19-Norvitamin D analogs for breast cancer therapy

The active form of vitamin D3, 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3 or calcitriol), is known to inhibit the proliferation and invasiveness of many types of cancer cells, including breast, colon, pancreatic, prostate, and liver cancer cells. These findings support the use of 1α,25(OH)2D3 for the treatment of these types of cancer. However, 1α,25(OH)2D3 can cause hypercalcemia, so analogs of 1α,25(OH)2D3 that are less calcemic but exhibit more potent anti-tumor activity would be good candidates as therapeutic agents. Therefore, a series of 19-norvitamin D analogs, in which the methylidene group on C19 is replaced with 2 hydrogen atoms, have been synthesized by several laboratories. In our laboratory, we have designed and synthesized a series of 2α-functional group substituted 19-norvitamin D3 analogs and examined their anti-proliferative activity. Among them, 2α- and 2β-(3-hydroxypropyl)-1α,25-dihydroxy-19-norvitamin D3 (MART-10 and MART-11) were found to be the most promising. Here, we review the rationale and approaches for the synthesis of different 19-norvitamin D analogs, and the pre-clinical studies using these analogs in breast cancer cells, in particular, we chose MART-10 for its potential application to the prevention and treatment of breast cancer.

Cancer cytogenetics: methodology revisited

The Philadelphia chromosome was the first genetic abnormality discovered in cancer (in 1960), and it was found to be consistently associated with CML. The description of the Philadelphia chromosome ushered in a new era in the field of cancer cytogenetics. Accumulating genetic data have been shown to be intimately associated with the diagnosis and prognosis of neoplasms; thus, karyotyping is now considered a mandatory investigation for all newly diagnosed leukemias. The development of FISH in the 1980s overcame many of the drawbacks of assessing the genetic alterations in cancer cells by karyotyping. Karyotyping of cancer cells remains the gold standard since it provides a global analysis of the abnormalities in the entire genome of a single cell. However, subsequent methodological advances in molecular cytogenetics based on the principle of FISH that were initiated in the early 1990s have greatly enhanced the efficiency and accuracy of karyotype analysis by marrying conventional cytogenetics with molecular technologies. In this review, the development, current utilization, and technical pitfalls of both the conventional and molecular cytogenetics approaches used for cancer diagnosis over the past five decades will be discussed.

High-resolution detection of recurrent aberrations in lung adenocarcinomas by array comparative genomic hybridization and expression analysis of selective genes by quantitative PCR

Genomic abnormalities are the hallmark of cancers and may harbor potential candidate genes important for cancer development and progression. We performed array comparative genomic hybridization (array CGH) on 36 cases of primary lung adenocarcinoma (AD) using an array containing 2621 BAC or PAC clones spanning the genome at an average interval of 1 Mb. Array CGH identified the commonest aberrations consisting of DNA gains within 1p, 1q, 5p, 5q, 7p, 7q, 8q, 11q, 12p, 13q, 16p, 17q, 20q, and losses with 6q, 9p, 10q and 18q. High-level copy gains involved mainly 7p21-p15 and 20q13.3. Dual color fluorescence in situ hybridization (FISH) was performed on a selective locus for validation of array CGH results. Genomic aberrations were compared with different clinicopathological features and a trend of higher number of aberrations in tumors with aggressive phenotypes and current tobacco exposure was identified. According to array CGH data, 23 candidate genes were selected for quantitative PCR (qPCR) analysis. The concordance observed between the genomic and expression changes in most of the genes suggested that they could be candidate cancer-related genes that contributed to the development of lung AD.

Genistein suppresses prostate cancer growth through inhibition of oncogenic microRNA-151

Genistein has been shown to suppress the growth of several cancers through modulation of various pathways. However, the effects of genistein on the regulation of oncogenic microRNA-151 (miR-151) have not been reported. In this study, we investigated whether genistein could alter the expression of oncogenic miR-151 and its target genes that are involved in the progression and metastasis of prostate cancer (PCa). Real-time RT-PCR showed that the expression of miR-151 was higher in PC3 and DU145 cells compared with RWPE-1 cells. Treatment of PC3 and DU145 cells with 25 µM genistein down-regulated the expression of miR-151 compared with vehicle control. Inhibition of miR-151 in PCa cells by genistein significantly inhibited cell migration and invasion. In-silico analysis showed that several genes (CASZ1, IL1RAPL1, SOX17, N4BP1 and ARHGDIA) suggested to have tumor suppressive functions were target genes of miR-151. Luciferase reporter assays indicated that miR-151 directly binds to specific sites on the 3′UTR of target genes. Quantitative real-time PCR analysis showed that the mRNA expression levels of the five target genes in PC3 and DU145 were markedly changed with miR-151 mimics and inhibitor. Kaplan-Meier curves and log-rank tests revealed that high expression levels of miR-151 had an adverse effect on survival rate. This study suggests that genistein mediated suppression of oncogenic miRNAs can be an important dietary therapeutic strategy for the treatment of PCa.

Dose-dependent activation of putative oncogene SBSN by BORIS

Testis-specific transcription factor BORIS (Brother of the Regulator of Imprinted Sites), a paralog and proposed functional antagonist of the widely expressed CTCF, is abnormally expressed in multiple tumor types and has been implicated in the epigenetic activation of cancer-testis antigens (CTAs). We have reported previously that suprabasin (SBSN), whose expression is restricted to the epidermis, is epigenetically derepressed in lung cancer. In this work, we establish that SBSN is a novel non-CTA target of BORIS epigenetic regulation. With the use of a doxycycline-inducible BORIS expressing vector, we demonstrate that relative BORIS dosage is critical for SBSN activation. At lower concentrations, BORIS induces demethylation of the SBSN CpG island and disruption and activation of chromatin around the SBSN transcription start site (TSS), resulting in a 35-fold increase in SBSN expression in the H358 human lung cancer cell line. Interestingly, increasing BORIS concentrations leads to a subsequent reduction in SBSN expression via chromatin repression. In a similar manner, increase in BORIS concentrations leads to eventual decrease of cell growth and colony formation. This is the first report demonstrating that different amount of BORIS defines its varied effects on the expression of a target gene via chromatin structure reorganization.

Risk factors for primary lung cancer among never smokers by gender in a matched case-control study

OBJECTIVE

Lung cancers that occur in never smokers differ from those that occur in smokers. We performed an analysis of potential epidemiological risk factors for lung cancer among never smokers.

METHODS

In this hospital-based matched case-control study, all 1,540 matched case-control pairs were Han Chinese in Taiwan. The data on demographic characteristics, smoking habit, exposure to environmental tobacco smoke, medical history of lung diseases, family history of lung cancer, and female characteristics were collected from a structured questionnaire. A multiple conditional logistic regression was used to estimate odds ratios and 95 % confidence intervals after adjusting for possible confounders.

RESULTS

Overall, several epidemiological factors of lung cancer in never smokers were different between males and females. For the female population, subjects who were exposed to environmental tobacco smoke (OR = 1.39, 95 % CI = 1.17-1.67) with a history of pulmonary tuberculosis and with family history of lung cancer in first-degree relatives (OR = 2.44, 95 % CI = 1.79-3.32) had higher risk of lung cancer, while subjects with a history of hormone replacement therapy and using fume extractors for those who cooked were protective. For the male population, only subjects with family history of lung cancer in first-degree relatives (OR = 2.77, 95 % CI = 1.53-5.01) were significantly associated with risk of lung cancer.

CONCLUSION

This study provides insights about the epidemiological factors of lung cancer in never smokers, adding to existing evidence that family history of lung cancer and environmental tobacco smoke may moderate lung cancer risk.

Lung adenocarcinoma of never smokers and smokers harbor differential regions of genetic alteration and exhibit different levels of genomic instability

Recent evidence suggests that the observed clinical distinctions between lung tumors in smokers and never smokers (NS) extend beyond specific gene mutations, such as EGFR, EML4-ALK, and KRAS, some of which have been translated into targeted therapies. However, the molecular alterations identified thus far cannot explain all of the clinical and biological disparities observed in lung tumors of NS and smokers. To this end, we performed an unbiased genome-wide, comparative study to identify novel genomic aberrations that differ between smokers and NS.

High resolution whole genome DNA copy number profiling of 69 lung adenocarcinomas from smokers (n = 39) and NS (n = 30) revealed both global and regional disparities in the tumor genomes of these two groups. We found that NS lung tumors had a greater proportion of their genomes altered than those of smokers. Moreover, copy number gains on chromosomes 5q, 7p, and 16p occurred more frequently in NS. We validated our findings in two independently generated public datasets. Our findings provide a novel line of evidence distinguishing genetic differences between smoker and NS lung tumors, namely, that the extent of segmental genomic alterations is greater in NS tumors. Collectively, our findings provide evidence that these lung tumors are globally and genetically different, which implies they are likely driven by distinct molecular mechanisms.

A novel role for hSMG-1 in stress granule formation

hSMG-1 is a member of the phosphoinositide 3 kinase-like kinase (PIKK) family with established roles in nonsense-mediated decay (NMD) of mRNA containing premature termination codons and in genotoxic stress responses to DNA damage. We report here a novel role for hSMG-1 in cytoplasmic stress granule (SG) formation. Exposure of cells to stress causing agents led to the localization of hSMG-1 to SG, identified by colocalization with TIA-1, G3BP1, and eIF4G. hSMG-1 small interfering RNA and the PIKK inhibitor wortmannin prevented formation of a subset of SG, while specific inhibitors of ATM, DNA-PK(cs), or mTOR had no effect. Exposure of cells to H(2)O(2) and sodium arsenite induced (S/T)Q phosphorylation of proteins. While Upf2 and Upf1, an essential substrate for hSMG-1 in NMD, were present in SG, NMD-specific Upf1 phosphorylation was not detected in SG, indicating hSMG-1's role in SG is separate from classical NMD. Thus, SG formation appears more complex than originally envisaged and hSMG-1 plays a central role in this process.

Lung cancers unrelated to smoking: characterized by single oncogene addiction?

Lung cancer is a major cause of cancer-related mortality worldwide. Currently, adenocarcinoma is its most common histological subtype in many countries. In contrast with small cell lung cancer or squamous cell carcinoma, lung adenocarcinoma often arises in never-smokers, especially in East Asian countries, as well as in smokers. Adenocarcinoma in never-smokers is associated with a lower incidence of genetic alterations (i.e., somatic mutations, loss of heterozygosity, and methylation) than in smokers. In addition, most adenocarcinomas in never-smokers harbor one of the proto-oncogene aberrations that occur in a mutually exclusive manner (EGFR mutation, KRAS mutation, HER2 mutations, or ALK translocation). It is of note that the proliferation and survival of lung cancer cells that harbor one of these oncogenic aberrations depend on the signaling from each aberrantly activated oncoprotein (oncogene addiction). Therefore, most adenocarcinomas in never-smokers can be effectively treated by molecularly targeted drugs that inhibit each oncoprotein. Moreover, from a pathological aspect, lung adenocarcinoma in never-smokers is characterized by terminal respiratory unit-type adenocarcinoma and a particular gene expression profile. Finally, epidemiological analyses have identified many candidate causes of lung cancer in never-smokers (genetic, environmental, and hormonal factors). The elucidation of the particular features of lung cancer unrelated to smoking and the development of new therapeutic modalities may reduce the mortality from lung cancers in the future.

Genomic profiles specific to patient ethnicity in lung adenocarcinoma

PURPOSE

East-Asian (EA) patients with non-small-cell lung cancer (NSCLC) are associated with a high proportion of nonsmoking women, epidermal growth factor receptor (EGFR)-activating somatic mutations, and clinical responses to tyrosine kinase inhibitors. We sought to identify novel molecular differences between NSCLCs from EA and Western European (WE) patients.

EXPERIMENTAL DESIGN

A total of 226 lung adenocarcinoma samples from EA (n = 90) and WE (n = 136) patients were analyzed for copy number aberrations (CNA) by using a common high-resolution SNP (single nucleotide polymorphism) microarray platform. Univariate and multivariate analyses were carried out to identify CNAs specifically related to smoking history, EGFR mutation status, and ethnicity.

RESULTS

The overall genomic profiles of adenocarcinomas from EA and WE patients were highly similar. Univariate analyses revealed several CNAs significantly associated with ethnicity, EGFR mutation, and smoking, but not to gender, and KRAS or p53 mutations. A multivariate model identified four ethnic-specific recurrent CNAs-significantly higher rates of copy number gain were observed on 16p13.13 and 16p13.11 in EA tumors, whereas higher rates of genomic loss on 19p13.3 and 19p13.11 were observed in tumors from WE patients. We identified several potential driver genes in these regions, showing a positive correlation between cis-localized copy number changes and transcriptomic changes.

CONCLUSION

16p copy number gains (EA) and 19p losses (WE) are ethnic-specific chromosomal aberrations in lung adenocarcinoma. Patient ethnicity should be considered when evaluating future NSCLC therapies targeting genes located on these areas.

Outcome and treatment strategy in female lung cancer: a single institution experience

PURPOSE

To assess the survival rate of female lung cancer treated at the Institute of Oncology of the Vilnius University, Lithuania during the period between 1996-2005.

MATERIALS AND METHODS

During the period between 1996-2005, 471 women diagnosed with lung cancer were treated at the Department of Thoracic Surgery and Oncology of the Institute of Oncology, Vilnius University. Data on morphology, stage and treatment was collected from the medical records. All lung cancer cases by histology were classified in two groups: non-small cell lung cancer (includes squamous cell carcinoma, large cell carcinoma, adenocarcinoma and other less common types) and small cell lung cancer. The vital status of the study group was assessed as of December 31, 2007, by passive follow-up, using data from the population registry. It was found that 411 (87.3%) of the patients had died. Survival was estimated according to the Kaplan-Meier method.

RESULTS

The median survival of female lung cancer diagnosed during 1996-2005 in Lithuania show to be 8.7 months (8.4 (95% CI 7.2-10.8) months with non-small cell lung cancer and 9.3 (95% CI 6.3-13.0) months with small-cell lung cancer). Survival was more than 20 months in resectable non-small cell lung cancer (stages I, II, IIIA). Non-small cell lung cancer survival in advanced stages was less than 7 months. Small-cell lung cancer patients median survival at limited and extended stages of the disease were 9.5 (95% CI 2.9-18.4) compared to 9.2 (95% CI 6.2-13.7) months. Non-small cell lung cancer patients most frequently were treated by surgery (27.0%), surgery and chemotherapy or radiotherapy (19.6%). Small cell lung cancer patient treatment included chemo and radiotherapy (27.0%), chemotherapy (19.0%), radiotherapy (17.5%), surgery (27.9%).

CONCLUSIONS

The single center study of female lung cancer diagnosed during 1996-2005 in Lithuania show a significantly better chance of survival in resectable non-small cell lung cancer. Advanced stages of the disease at the time of diagnosis and choice of treatment options of female lung cancer in the country still remains an issue.

PDRG1, a novel tumor marker for multiple malignancies that is selectively regulated by genotoxic stress

We have previously cloned and characterized a novel p53 and DNA damage-regulated gene named PDRG1. PDRG1 was found to be differentially regulated by ultraviolet (UV) radiation and p53. In this study, we further investigated stress regulation of PDRG1 and found it to be selectively regulated by agents that induce genotoxic stress (DNA damage). Using cancer profiling arrays, we also investigated PDRG1 expression in matching normal and tumor samples representing various malignancies and found its expression to be upregulated in multiple malignancies including cancers of the colon, rectum, ovary, lung, stomach, breast and uterus when compared to their respective matched normal tissues. Western blot and immunohistochemical analyses were also performed on select specimen sets of colon cancers and matching normal tissues and the results also indicated PDRG1 overexpression in tumors relative to normal tissues. To gain insight into the function of PDRG1, we performed PDRG1 knockdown in human colon cancer cells and found its depletion to result in marked slowdown of tumor cell growth. These results suggest that PDGR1 may be linked to cell growth regulation. Yeast two-hybrid screen also led to the identification of PDCD7, CIZ1 and MAP1S as PDRG1-interacting proteins that are involved in apoptosis and cell cycle regulation which further implicate PDRG1 in controlling cell growth regulation. Taken together, our results indicate that PDRG1 expression is increased in multiple human malignancies suggesting it to be a high-value novel tumor marker that could play a role in cancer development and/or progression.

Genomic aberrations in lung adenocarcinoma in never smokers

Background

Lung cancer in never smokers would rank as the seventh most common cause of cancer death worldwide.

Methods and Findings

We performed high-resolution array comparative genomic hybridization analysis of lung adenocarcinoma in sixty never smokers and identified fourteen new minimal common regions (MCR) of gain or loss, of which five contained a single gene (MOCS2, NSUN3, KHDRBS2, SNTG1 and ST18). One larger MCR of gain contained NSD1. One focal amplification and nine gains contained FUS. NSD1 and FUS are oncogenes hitherto not known to be associated with lung cancer. FISH showed that the amplicon containing FUS was joined to the next telomeric amplicon at 16p11.2. FUS was over-expressed in 10 tumors with gain of 16p11.2 compared to 30 tumors without that gain. Other cancer genes present in aberrations included ARNT, BCL9, CDK4, CDKN2B, EGFR, ERBB2, MDM2, MDM4, MET, MYC and KRAS. Unsupervised hierarchical clustering with adjustment for false-discovery rate revealed clusters differing by the level and pattern of aberrations and displaying particular tumor characteristics. One cluster was strongly associated with gain of MYC. Another cluster was characterized by extensive losses containing tumor suppressor genes of which RB1 and WRN. Tumors in that cluster frequently harbored a central scar-like fibrosis. A third cluster was associated with gains on 7p and 7q, containing ETV1 and BRAF, and displayed the highest rate of EGFR mutations. SNP array analysis validated copy-number aberrations and revealed that RB1 and WRN were altered by recurrent copy-neutral loss of heterozygosity.

Conclusions

The present study has uncovered new aberrations containing cancer genes. The oncogene FUS is a candidate gene in the 16p region that is frequently gained in never smokers. Multiple genetic pathways defined by gains of MYC, deletions of RB1 and WRN or gains on 7p and 7q are involved in lung adenocarcinoma in never smokers.

Chromosomal imbalances in lung adenocarcinomas with or without mutations in the epidermal growth factor receptor gene

BACKGROUND AND OBJECTIVE

Epidermal growth factor receptor (EGFR) mutations are common in lung adenocarcinomas of Asian patients, implying a good response to treatment with the EGFR tyrosine kinase inhibitors, gefitinib and erlotinib. However, the distinct chromosomal imbalances between lung adenocarcinomas with and those without EGFR mutations have not been fully elucidated.

METHODS

Seventy-seven patients of surgically resected lung adenocarcinoma were analysed for the EGFR exon 19 deletion and the L858R mutation, using mutant-enriched PCR, and for chromosomal imbalance alterations using comparative genomic hybridization.

RESULTS

EGFR mutations were detected in 42 (54.5%) patients, including 22 with the exon 19 deletion and 20 with the L858R mutation. The mean number of chromosomal arms with imbalance alterations was significantly higher in tumours with EGFR mutations than in those lacking these two mutations. The minimal regions with gain on 1q23-q31, 6p12-p21.1 and 7q11.2, and loss on 3p21, 8p22-p23, 9q33, 10q25 and 13q13, differed significantly between lung adenocarcinomas with or without EGFR mutations. However, neither EGFR mutations, nor any of the common chromosomal imbalance alterations alone, exhibited significant associations with tumour stage or disease-specific survival of the patients.

CONCLUSIONS

These results indicate that imbalance alterations at several chromosomal regions occur significantly more frequently in lung adenocarcinomas with EGFR mutations than in those without such mutations. Tumour growth-related genes in these chromosomal regions should be further investigated to improve our understanding of the common genetic alterations in lung adenocarcinomas with EGFR mutations.

A novel translocation breakpoint within the BPTF gene is associated with a pre-malignant phenotype

Partial gain of chromosome arm 17q is an abundant aberrancy in various cancer types such as lung and prostate cancer with a prominent occurrence and prognostic significance in neuroblastoma – one of the most common embryonic tumors. The specific genetic element/s in 17q responsible for the cancer-promoting effect of these aberrancies is yet to be defined although many genes located in 17q have been proposed to play a role in malignancy. We report here the characterization of a naturally-occurring, non-reciprocal translocation der(X)t(X;17) in human lung embryonal-derived cells following continuous culturing. This aberrancy was strongly correlated with an increased proliferative capacity and with an acquired ability to form colonies in vitro. The breakpoint region was mapped by fluorescence in situ hybridization (FISH) to the 17q24.3 locus. Further characterization by a custom-made comparative genome hybridization array (CGH) localized the breakpoint within the Bromodomain PHD finger Transcription Factor gene (BPTF), a gene involved in transcriptional regulation and chromatin remodeling. Interestingly, this translocation led to elevation in the mRNA levels of the endogenous BPTF. Knock-down of BPTF restricted proliferation suggesting a role for BPTF in promoting cellular growth. Furthermore, the BPTF chromosomal region was found to be amplified in various human tumors, especially in neuroblastomas and lung cancers in which 55% and 27% of the samples showed gain of 17q24.3, respectively. Additionally, 42% percent of the cancer cell lines comprising the NCI-60 had an abnormal BPTF locus copy number. We suggest that deregulation of BPTF resulting from the translocation may confer the cells with the observed cancer-promoting phenotype and that our cellular model can serve to establish causality between 17q aberrations and carcinogenesis.

Genetic variants cis-regulating Xrn2 expression contribute to the risk of spontaneous lung tumor

Gene expression variation is an important mechanism underlying susceptibility to complex disease. In comparison with tobacco-related lung carcinogenesis, lung cancer in nonsmokers may involve important and etiologically distinct causal pathways. In this study, we conducted a genome-wide association study on spontaneous lung tumor incidence in inbred mice and identified a major susceptibility locus on mouse chromosome 2 (rs27328255, P=6.68 x 10(-7)). We then evaluated the correlations of polymorphisms with the transcription of positional candidate genes in normal lungs. Single-nucleotide polymorphism rs27328255 was consistently and strongly associated (P=7.42 x 10(-9)) in cis with transcript levels of Xrn2. We further showed that Xrn2 promotes proliferation and inhibits squamous differentiation in human lung epithelial cells and polymorphisms in human homolog XRN2 are associated with human lung cancer (rs2025811, P=1.90 x 10(-3), OR=1.20). We conclude that genetic variants regulating Xrn2 expression in cis are determinants of spontaneous lung tumor susceptibility in mice and have genetic equivalents in lung cancer susceptibility in human beings. Identifying Xrn2 as a major candidate for spontaneous lung cancer has important implications for the diagnosis and treatment of lung cancer as well as delineation of the mechanisms underlying the genesis of lung cancer in nonsmokers.

The NER proteins are differentially expressed in ever smokers and in never smokers with lung adenocarcinoma

BACKGROUND

The expression levels of excision repair cross-complementation group 1 (ERCC1), replication protein A (RPA) and xeroderma pigmentosum group F (XPF) nucleotide excision repair proteins may be important in the response to platin-based therapy in lung cancer patients. It is not known whether ERCC1, RPA and XPF expression levels differ between ever smokers (ES) and never smokers (NS).

PATIENTS AND METHODS

ERCC1, RPA and XPF expression levels were immunohistochemically evaluated in 125 patients with resected lung adenocarcinoma (AC) and carefully reviewed smoking status.

RESULTS

ERCC1 was correlated with XPF (P = 0.001), but not with RPA (P = 0.11). In the univariate analysis, ERCC1 and XPF levels were higher in NS compared with ES (P = 0.004 and P = 0.003, respectively). In the multivariate analysis, the smoking status was predictive of the ERCC1 level [odds ratio (OR) 2.5, 95% confidence interval (CI) 1.03-6.2] after adjustment for variables linked to the smoking status, including age and the presence of bronchioloalveolar (BAC) features. The smoking status was also predictive of both RPA (OR 6.7, 95% CI 1.5-33.3) and XPF levels (OR 12.5, 95% CI 2.9-50) after adjusting for age, sex and BAC features.

CONCLUSION

In patients with resected lung AC, ERCC1, RPA and XPF expression levels are higher in NS compared with ES.

Comparative genome hybridization array analysis for sporadic Parkinson's disease

Parkinson disease (PD) is a common neurodegenerative disorder, characterized by the loss of midbrain dopamine neurons and Lewy body inclusions. We investigated array CGH to analyze gain or loss of genetic material from 30 patients with PD. We identified the frequent copy number variations in PD; gains in 1p21.1, 4p15.31, 5p15.33, 6q24.1, 7q35, 8q24.3, 10q26.3, 11p15.5-15.4, 12q21.2, 16p13.3, 18q12.3 and 22q13.31, and losses in 1p36.33, and 5q13.2. These findings enable a better description of genetic variations in PD, and could provide a foundation for understanding the critical regions of the genome that may be involved in the development of PD.

Mitogen-activated protein kinase activation in lung adenocarcinoma: a comparative study between ever smokers and never smokers

PURPOSE

There are major differences affecting genes in adenocarcinomas in ever and never smokers. However, data on whether mitogen-activated protein kinase (MAPK) activation state differs according to smoking status are limited.

EXPERIMENTAL DESIGN

Expression of activated extracellular signal-regulated kinases, c-Jun NH(2)-terminal kinases, and P38 enzymes (pP38) were evaluated by means of immunohistochemistry in 188 chemonaïve patients with surgically resected lung adenocarcinoma. Cell viability of the lung adenocarcinoma cell line HCC827 was studied after treatment with cisplatin or the P38 MAPK inhibitor SB 203580.

RESULTS

Thirty-seven of 44 never smokers [84%; 95% confidence intervals (95% CI), 70-92%] expressed high pP38 levels compared with 45 of 104 ever smokers (43%; 95% CI, 34-53%; P < 0.0001). The proportion of never smokers expressing high c-Jun NH(2)-terminal kinase levels (72%; 95% CI, 57-83%) was greater than that of ever smokers (53%; 95% CI, 44-62%; P = 0.03). The proportion of ever smokers expressing high extracellular signal-regulated kinase levels (51%; 95% CI, 42-59%) was similar to that of never smokers (57%; 95% CI, 42-71%; P = 0.47). Never smokers were 10.5 times (95% CI, 3.5-31.5) more likely to express high pP38 levels after adjustment for variables linked to smoking status, including age, sex, and histologic subtype. None of the activated MAPKs predicted for overall survival. Cell viability of HCC827 was significantly reduced after exposure to SB203580 alone or when combined with cisplatin.

CONCLUSIONS

Life-long nonsmoking is associated with high activated P38 levels in patients with lung adenocarcinoma. Activated P38 can contribute to the viability of adenocarcinoma cells in never smokers, but is not predictive for overall survival.

Broad overexpression of ribonucleotide reductase genes in mice specifically induces lung neoplasms

Ribonucleotide reductase (RNR) catalyzes the rate-limiting step in nucleotide biosynthesis and plays a central role in genome maintenance. Although a number of regulatory mechanisms govern RNR activity, the physiologic effect of RNR deregulation had not previously been examined in an animal model. We show here that overexpression of the small RNR subunit potently and selectively induces lung neoplasms in transgenic mice and is mutagenic in cultured cells. Combining RNR deregulation with defects in DNA mismatch repair, the cellular mutation correction system, synergistically increased RNR-induced mutagenesis and carcinogenesis. Moreover, the proto-oncogene K-ras was identified as a frequent mutational target in RNR-induced lung neoplasms. Together, these results show that RNR deregulation promotes lung carcinogenesis through a mutagenic mechanism and establish a new oncogenic activity for a key regulator of nucleotide metabolism. Importantly, RNR-induced lung neoplasms histopathologically resemble human papillary adenocarcinomas and arise stochastically via a mutagenic mechanism, making RNR transgenic mice a valuable model for lung cancer.

Women and lung cancer

OBJECTIVES

There is expanding evidence that lung cancer has a multitude of sex differences. This article will review these differences and discuss nursing implications for women with lung cancer.

DATA SOURCES

Research and journal articles.

CONCLUSION

Understanding the sex differences of lung cancer is essential for individualizing care for women with lung cancer.

IMPLICATIONS FOR NURSING PRACTICE

Nurses play an integral role throughout the trajectory of illness for women with lung cancer. Understanding the sex differences will help nurses to individualize the care for this population to meet their specific needs.

Chromosomal aberrations of malignant pleural effusions of lung adenocarcinoma: different cytogenetic changes are correlated with genders and smoking habits

Chromosomal aberrations of malignant cells from pleural effusions of 31 cases of lung adenocarcinoma were analyzed. Pooled CGH results showed frequent amplifications on chromosome arms 1p (22.6%), 1q (35.5%), 2q (25.8%), 3q (38.7%), 4q (41.9%), 5p (41.9%), 5q (51.6%), 6p (19.4%), 6q (25.8%), 7p (41.9%), 7q (35.5%), 8q (32.3%), 12q (38.7%), 13q (22.6%), 14q (35.5%), 17q (19.4%), Xp (22.6%), and Xq (38.7%). Frequent deletions were found on 1p (19.4%), 3p (16.1%), 4q (16.1%), 8p (25.8%), 9p (22.6%), 9q (29.0%), 10q (22.6%), 13q (22.6%), 16p (19.4%), 16q (22.6%), 17p (29.0%), 18q (16.1%), 19p (41.9%), 19q (32.3%), 20p (19.4%) and 22q (29%). These genomic changes were generally found consistent with previous reports of CGH analysis of primary tumors of lung adenocarcinoma. Loss of 19q and 22q were more frequently found in our studies (32.3% and 29.0%, respectively) than studies of primary tumors (less than 7% for both genetic changes). Gain of 11p, although not a frequent finding, was relatively more common in this (16%) than other studies (range, 2.9-11.8%). Interestingly, occurrences of 3p loss and 11p gain were higher in smokers than non-smokers, and deletion of 3p and increased copy number of 11p and Xp appeared more often in male than female patients. Among 17 male patients, gain of chromosomal 11p was a frequent aberration in tumors of smokers, while gain of Xp was more easily found in tumors of non-smokers. One candidate gene located within 11p15, lactate dehydrogenase C (LDHC), was selected for further study. Three cases with 11p gain had amplified FISH signals of LDHC. Also tumors from smokers or male had significantly higher transcript level of LDHC than non-smokers or female, respectively. The results demonstrate that different cytogenetic changes of malignant pleural effusions from lung adenocarcinoma are correlated with genders and smoking habits. The role of LDHC in the carcinogenesis of smoking-related lung adenocarcinoma, especially in male patients with pleural effusions, deserves further investigations.

Genetic and epigenetic regulation of the human prostacyclin synthase promoter in lung cancer cell lines

The importance of the arachidonic acid pathway has been established in colon and lung cancers, as well as in inflammatory diseases. In these diseases, prostacyclin I(2) (PGI2) and prostaglandin E(2) (PGE2) are thought to have antagonistic activities, with PGI2 exerting anti-inflammatory and antiproliferative activities, whereas PGE2 is proinflammatory and antiapoptotic. In human lung cancer, prostacyclin synthase (PGIS) and PGI2 are down-regulated, whereas PGE2 synthase (PGES) and PGE2 are up-regulated. Murine carcinogenesis models of human lung cancer reciprocate the relationship between PGIS and PGES expression. PGIS-overexpressing transgenic mice are protected from carcinogen- and tobacco smoke-induced lung tumor formation, suggesting that PGI2 may play a role in chemoprevention. We investigated several potential mechanisms for the down-regulation of PGIS in human lung cancer. Using transcription reporter assays, we show that single nucleotide polymorphisms in the PGIS promoter can affect transcriptional activity. In addition, PGIS expression in several human lung cancer cell lines is silenced by CpG methylation, and we have mapped these sites across the variable number of tandem repeats (VNTR) sequence in the promoter, as well as CpGs within exon 1 and the first intron. Finally, using fluorescence in situ hybridization, we show that human lung cancer cell lines and lung cancer tissues do not have a loss of the PGIS genomic region but multiple copies. These results show that an individual's PGIS promoter haplotype can play an important role in the predisposition for lung cancer and CpG methylation provides an epigenetic mechanism for the down-regulated PGIS expression.

Lung Cancer in Never Smokers: A Review

Lung cancer is the leading cause of cancer-related death in the United States. Although tobacco smoking accounts for the majority of lung cancer, approximately 10% of patients with lung cancer in the United States are lifelong never smokers. Lung cancer in the never smokers (LCINS) affects women disproportionately more often than men. Only limited data are available on the etiopathogenesis, molecular abnormalities, and prognosis of LCINS. Several etiologic factors have been proposed for the development of LCINS, including exposure to radon, cooking fumes, asbestos, heavy metals, and environmental tobacco smoke, human papillomavirus infection, and inherited genetic susceptibility. However, the relative significance of these individual factors among different ethnic populations in the development of LCINS has not been well-characterized. Adenocarcinoma is the predominant histologic subtype reported with LCINS. Striking differences in response rates and outcomes are seen when patients with advanced non–small-cell lung cancer (NSCLC) who are lifelong never smokers are treated with epidermal growth factor receptor tyrosine kinase (EGFR-TK) inhibitors such as gefitinib or erlotinib compared with the outcomes with these agents in patients with tobacco-associated lung cancer. Interestingly, the activating mutations in the EGFR-TK inhibitors have been reported significantly more frequently in LCINS than in patients with tobacco-related NSCLC. This review will summarize available data on the epidemiology, risk factors, molecular genetics, management options, and outcomes of LCINS.

Lung cancer in women: exploring sex differences in susceptibility, biology, and therapeutic response

Src tyrosine kinases regulate a large number of important mechanisms in normal and cancerous cells, are overexpressed in a broad range of tumors including lung cancer, and thus represent a potential target for cancer therapy. Preclinical experiments indicate that small-molecule inhibitors of Src block tumor growth, metastasis, and angiogenesis. Phase I data from healthy volunteers also suggest that inhibitors of Src prevent bone resorption. Several phase II trials with small-molecule inhibitors of Src are under way or have been initiated in lung cancer and in other malignancies, as discussed herein.

Comparative genomic hybridization array analysis and real time PCR reveals genomic alterations in squamous cell carcinomas of the lung

Genomic alterations have been identified in lung cancer tissues and reported in numerous studies. To analyze genomic aberrations in lung cancer patients, we used array comparative genomic hybridization (array CGH) in 14 squamous cell lung carcinoma (SqC) tissues. Copy number gain and loss in chromosomal regions were detected, and the corresponding genes were confirmed by real time PCR. Several frequently altered loci, including gain of 3q (36% of samples), were found. The most frequently identified losses were found at 14q32.33 (21% of samples). The relative degree of chromosomal change was analyzed using log2 ratios. High-level DNA amplifications (>0.8 log2 ratio) were detected at 20 regions in 1p, 2q, 3q, 4q, 6q, 7p, 8q, 9p, 10q, 12q, 14q and 19p. We found that the fold change levels were highest at EVI1 (3q26.2), LPP (3q27-28) and FHF-1 (3q28) gene loci. Our results show that array CGH is a useful tool for identification of gene alteration in lung cancer, and that the above-mentioned genes might represent potential candidate genes for pathogenesis and diagnosis of lung cancer.

Comparative Genomic Hybridization Array Analysis and Real-Time PCR Reveals Genomic Copy Number Alteration for Lung Adenocarcinomas

Genomic alterations in lung cancer tissues have been observed in various studies. To analyze the aberrations in the genome of lung cancer patients, we used array comparative genomic hybridization (array CGH) in 15 lung adenocarcinoma (AdC) tissues. Copy number gains and losses in chromosomal regions were detected and corresponding genes were confirmed by real-time polymerase chain reaction (PCR). As for the results, several frequently altered loci, including gain of 16p (46% of samples), were found, and the most common losses were found in 14q32.33 (26% of samples). High-level DNA amplifications (> 0.8 log(2) ratio) were detected at 1p, 5p, 7p, 9p, 11p, 11q, 12q, 14q, 16p, 17q, 19q, 20p, 21q, and 22q. A subset of genes, gained or lost, was checked for over- or underrepresentation by means of real-time PCR. The degree of fold change was highest in ECGF1 (22q13.33), HOXA9 (7p15.2), MAFG (17q25.3), TSC2 (16p13.3), and ICAM1 (19p13.2) genes and the 16p chromosome terminal region (16p13.3pter). Taken together, these results show that array CGH could be used as a powerful tool for identification of genomic alteration for lung cancer, and the above-mentioned genes may represent potential candidate genes in the study of lung cancer pathogenesis and diagnosis.