Clinical significance of TTF-1 protein expression and TTF-1 gene amplification in lung adenocarcinoma

Molecular pathology of non-small cell carcinoma

Currently, lung cancer is treated by the highest number of therapeutic options and the benefits are based on multiple large-scale sequencing studies, translational research and new drug development, which has promoted our understanding of the molecular pathology of lung cancer. According to the driver alterations, different characteristics have been revealed, such as differences in ethnic prevalence, median age and alteration patterns. Consequently, beyond traditional chemoradiotherapy, molecular-targeted therapy and treatment with immune check-point inhibitors (ICI) also became available major therapeutic options. Interestingly, clinical results suggest that the recently established therapies target distinct lung cancer proportions, particularly between the EGFR/ALK and PD-1/PD-L1-positive subsets, e.g. the kinase inhibitors target driver mutation-positive tumours, whereas driver mutation-negative tumours respond to ICI treatment. These therapeutic efficacy-related differences might be explained by the molecular pathogenesis of lung cancer. Addictive driver mutations promote tumour formation with powerful transformation performance, resulting in a low tumour mutation burden, reduced immune surveillance, and subsequent poor response to ICIs. In contrast, regular tobacco smoke exposure repeatedly injures the proximal airway epithelium, leading to accumulated genetic alterations. In the latter pathway, overgrowth due to alteration and immunological exclusion against neoantigens is initially balanced. However, tumours could be generated from certain clones that outcompete immunological exclusion and outgrow the others. Consequently, this cancer type responds to immune check-point treatment. These pathogenic differences are explained well by the two-compartment model, focusing upon the anatomical and functional composition of distinct cellular components between the terminal respiratory unit and the air-conducting system.

Sex-biased molecular differences in lung adenocarcinoma are ethnic and smoking specific

BACKGROUND

Sex-related differences in cancer epidemiology, tumor biology, immune system activity, and pharmacogenomics have been suggested to be important considerations for precision cancer control. Here we elucidated systematically sex biases in genetic variants, gene expression profiles, and immunological landscapes of lung adenocarcinoma patients (LUADs) with different ancestry and smoking status.

METHODS

Somatic mutation and mRNA expression data of Asian and Non-Asian LUADs were obtained from public databases. Sex-biased genetic mutations, gene expression, biological pathways, and immune infiltration were identified in the context of smoking status and race.

RESULTS

Among nonsmokers, male-biased mutations were prevalent in Asian LUADs, while few sex-biased mutations were detected in Non-Asian LUADs. EGFR was the only mutation whose frequency was significantly higher in females than males in both Asian and Non-Asian nonsmokers. More genes exhibited sex-biased expression in Non-Asian LUADs compared to Asian LUADs. Moreover, genes distinctly expressed in females were mainly related to immune-related pathways, whereas those in males were more involved in activation of DNA repair, E2F_targets, and MYC_targets pathways. We also detected sex-specific immune infiltration in the context of genetic variation. In EGFR-mutant LUADs, males had a significantly increased infiltration of CD8 + T cells, whereas resting CD4 + memory T cells were more abundant in females. Additionally, in KRAS-mutant LUADs, CD8 + and CD4 + T cells were more abundant in females than males. In addition, we detected all female patients with high SCGB3A2 expression were exclusively sensitive to immunotherapy, while this phenomenon was not observed in male patients.

CONCLUSIONS

Our findings provided evidence that sex-related molecular and cellular components are involved in shaping tumor distinct genetic and immune features, which might have important impact on personalized targeted and immune therapy.

Expression landscapes in non-small cell lung cancer shaped by the thyroid transcription factor 1

TTF-1-expressing non-small cell lung cancer (NSCLC) is one of the most prevalent lung cancer types worldwide. However, theparadoxical activity of TTF-1 in both lung carcinogenesis and tumor suppression is believed to be context-dependentwhich calls for a deeper understanding about the pathological expression of TTF-1. In addition, the expression circuitry of TTF-1-target genes in NSCLC has not been well examined which necessitates to revisit the involvement of TTF-1- in a multitude of oncologic pathways. We used RNA-seq and clinical data of patients from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx), including ChIP-seq data from different NSCLC cell lines, and mapped the proteome of NSCLC tumor. Our analysis showed significant variability in TTF-1 expression among NSCLC,and further clarified that this variability is orchestrated at the transcriptional level. We also found that high TTF-1 expression could negatively influence the survival outcomes of stage 1 LUAD which may be attributed to growth factor receptor-driven activation of mitogenic and angiogenic pathways. Mechanistically, TTF-1 may also control the genes associated with pathways involved in acquired TKI drug resistance or response to immune checkpoint inhibitors. Lastly, proteome-based biomarker discovery in stage 1 LUAD showed that TTF-1 positivity is potentially associated with the upregulation of several oncogenes which includes interferon proteins, MUC1, STAT3, and EIF2AK2. Collectively, this study highlights the potential involvement of TTF-1 in cell proliferation, immune evasion, and angiogenesis in early-stage NSCLC.

Retrospective Data Analysis of Patients With Metastatic Lung Adenocarcinoma With or Without KRAS-Mutation or TTF1-Expression

Introduction

Patients with lung adenocarcinoma not expressing TTF1 and those with a KRAS mutation have worse prognosis. However, available data are limited and sometimes contradictory. Therefore, this retrospective cohort analysis aimed to clarify whether there was a difference in overall survival and progression-free survival between these groups of patients.

Methods

In total, data derived from 181 patients with metastatic lung adenocarcinoma treated at the Martha-Maria Halle-Dölau Hospital from 2016 to 2019 were analyzed. Kaplan-Meier curves were generated, and associated values, such as median survival and its confidence intervals, were determined using the log-rank test.

Results

A benefit in overall survival (OS) (8.4 vs 5.8 months; HR, .8; 95% CI, .53-1.19; P = .267) was associated with positive TTF1 expression, but this was not statistically significant. The same trend was shown with the progressive free survival (PFS) (6.5 vs 4.6 months; HR, .76; 95% CI, .51-1.20; P = .162). In patients with a KRAS mutation, there was no difference in OS compared to those with a wildtype KRAS. The median survival was almost identical at 7.5 months (KRAS mutation, 95% CI, 3.32-11.74) and 7.0 months (KRAS wildtype, 95% CI, 3.59-10.41). Additionally, in PFS, there was no difference between the 2 groups (5.8 vs 6.3 months).

Conclusions

Our analysis did not show a worse prognosis in patients with a KRAS mutation or in those with missing TTF1 expression, which is most likely related to the new therapeutic options. As a result of the administration of immunotherapy in patients with a KRAS mutation and the change from a regimen containing pemetrexed to a regimen containing no pemetrexed, the corresponding patients no longer seem to have a worse prognosis.

NKX2-1 re-expression induces cell death through apoptosis and necrosis in dedifferentiated thyroid carcinoma cells

NK2 homeobox 1 (NKX2-1) is a thyroid transcription factor essential for proper thyroid formation and maintaining its physiological function. In thyroid cancer, NKX2-1 expression decreases in parallel with declined differentiation. However, the molecular pathways and mechanisms connecting NKX2-1 to thyroid cancer phenotypes are largely unknown. This study aimed to examine the effects of NKX2-1 re-expression on dedifferentiated thyroid cancer cell death and explore the underlying mechanisms. A human papillary thyroid carcinoma cell line lacking NKX2-1 expression was infected with an adenoviral vector containing Nkx2-1. Cell viability decreased after Nkx2-1 transduction and apoptosis and necrosis were detected. Arginase 2 (ARG2), regulator of G protein signaling 4 (RGS4), and RGS5 mRNA expression was greatly increased in Nkx2-1-transducted cells. After suppressing these genes by siRNA, cell death, apoptosis, and necrosis decreased in RGS4 knockdown cells. These findings demonstrated that cell death was induced via apoptosis and necrosis by NKX2-1 re-expression and involves RGS4.

An NKX2-1/ERK/WNT feedback loop modulates gastric identity and response to targeted therapy in lung adenocarcinoma

Cancer cells undergo lineage switching during natural progression and in response to therapy. NKX2-1 loss in human and murine lung adenocarcinoma leads to invasive mucinous adenocarcinoma (IMA), a lung cancer subtype that exhibits gastric differentiation and harbors a distinct spectrum of driver oncogenes. In murine BRAFV600E-driven lung adenocarcinoma, NKX2-1 is required for early tumorigenesis, but dispensable for established tumor growth. NKX2-1-deficient, BRAFV600E-driven tumors resemble human IMA and exhibit a distinct response to BRAF/MEK inhibitors. Whereas BRAF/MEK inhibitors drive NKX2-1-positive tumor cells into quiescence, NKX2-1-negative cells fail to exit the cell cycle after the same therapy. BRAF/MEK inhibitors induce cell identity switching in NKX2-1-negative lung tumors within the gastric lineage, which is driven in part by WNT signaling and FoxA1/2. These data elucidate a complex, reciprocal relationship between lineage specifiers and oncogenic signaling pathways in the regulation of lung adenocarcinoma identity that is likely to impact lineage-specific therapeutic strategies.

Feasibility study of cryobiopsy for practical pathological diagnosis of primary lung cancer including immunohistochemical assessment

BACKGROUND

Precision medicine in non-small cell lung cancer requires attainment of a sufficient amount of high-quality tumor tissue. Transbronchial cryobiopsy has emerged as a new diagnostic method for non-neoplastic lung disease with a better potential to assess morphology compared with conventional methods. However, the influence of cryobiopsy on specimen quality, particularly detection of protein expression, is unknown. We performed a comparative immunohistochemical study in specimens obtained by cryobiopsy versus conventional sampling to evaluate the feasibility of cryobiopsy for lung cancer diagnosis.

METHODS

Pairs of artificial biopsy specimens, collected using a cryoprobe or conventional scalpel, were obtained from 43 surgically resected primary lung tumors. Formalin-fixed, paraffin-embedded blocks were prepared in an ISO15189-certified laboratory. Immunohistochemical staining of thyroid transcription factor-1, p40, Ki67 and programmed death-ligand 1 (22C3) was performed. The H-scores for thyroid transcription factor-1 and p40, labeling index for Ki67 and tumor proportion score for programmed death-ligand 1 were assessed. Pearson's correlation coefficients between two sampling types were calculated.

RESULTS

The thyroid transcription factor-1 and p40 H-scores showed perfect correlations between the cryobiopsy and conventional scalpel-obtained specimens (R2 = 0.977 and 0.996, respectively). Ki67 labeling index and PD-L1 tumor proportion score also showed strong correlations between the two sample types (R2 = 0.896 and 0.851, respectively). Five cases (11.6%) exhibited differences in tumor proportion score category between sample types, potentially because of intratumoral heterogeneity.

CONCLUSIONS

Immunohistochemical expression of certain tumor markers showed a high concordance between cryobiopsy and conventional scalpel sampling. Cryobiopsy is feasible for pathological diagnostics including PD-L1 evaluation.

Predicting Deep Learning Based Multi-Omics Parallel Integration Survival Subtypes in Lung Cancer Using Reverse Phase Protein Array Data

Mortality attributed to lung cancer accounts for a large fraction of cancer deaths worldwide. With increasing mortality figures, the accurate prediction of prognosis has become essential. In recent years, multi-omics analysis has emerged as a useful survival prediction tool. However, the methodology relevant to multi-omics analysis has not yet been fully established and further improvements are required for clinical applications. In this study, we developed a novel method to accurately predict the survival of patients with lung cancer using multi-omics data. With unsupervised learning techniques, survival-associated subtypes in non-small cell lung cancer were first detected using the multi-omics datasets from six categories in The Cancer Genome Atlas (TCGA). The new subtypes, referred to as integration survival subtypes, clearly divided patients into longer and shorter-surviving groups (log-rank test: p = 0.003) and we confirmed that this is independent of histopathological classification (Chi-square test of independence: p = 0.94). Next, an attempt was made to detect the integration survival subtypes using only one categorical dataset. Our machine learning model that was only trained on the reverse phase protein array (RPPA) could accurately predict the integration survival subtypes (AUC = 0.99). The predicted subtypes could also distinguish between high and low risk patients (log-rank test: p = 0.012). Overall, this study explores novel potentials of multi-omics analysis to accurately predict the prognosis of patients with lung cancer.

An in vivo functional genomics screen of nuclear receptors and their co-regulators identifies FOXA1 as an essential gene in lung tumorigenesis

Using a mini-library of 1062 lentiviral shRNAs targeting 40 nuclear hormone receptors and 70 of their co-regulators, we searched for potential therapeutic targets that would be important during in vivo tumor growth using a parallel in vitro and in vivo shRNA screening strategy in the non-small cell lung cancer (NSCLC) line NCI-H1819. We identified 21 genes essential for in vitro growth, and nine genes specifically required for tumor survival in vivo, but not in vitro: NCOR2, FOXA1, HDAC1, RXRA, RORB, RARB, MTA2, ETV4, and NR1H2. We focused on FOXA1, since it lies within the most frequently amplified genomic region in lung adenocarcinomas. We found that 14q-amplification in NSCLC cell lines was a biomarker for FOXA1 dependency for both in vivo xenograft growth and colony formation, but not mass culture growth in vitro. FOXA1 knockdown identified genes involved in electron transport among the most differentially regulated, indicating FOXA1 loss may lead to a decrease in cellular respiration. In support of this, FOXA1 amplification was correlated with increased sensitivity to the complex I inhibitor phenformin. Integrative ChipSeq analyses reveal that FOXA1 functions in this genetic context may be at least partially independent of NKX2-1. Our findings are consistent with a neomorphic function for amplified FOXA1, driving an oncogenic transcriptional program. These data provide new insight into the functional consequences of FOXA1 amplification in lung adenocarcinomas, and identify new transcriptional networks for exploration of therapeutic vulnerabilities in this patient population.

The prognostic effect of TTF-1 expression in the Chinese population of patients with advanced lung adenocarcinomas

Background

Thyroid transcription factor 1 (TTF-1), which is usually expressed by lung adenocarcinomas and small cell carcinomas, is usually used to distinguish adenocarcinoma and small cell carcinoma from cells of another type of lung cancer. We examined the association between TTF-1 expression and overall survival between patients with stage IV pulmonary adenocarcinoma to investigate the role of TTF-1 as a predictive and/or prognostic tumor marker in patients with advanced lung adenocarcinomas.

Methods

Analysis of the clinicopathologic features, treatment regimens, and overall survival of 209 lung adenocarcinoma patients who had been detected for TTF-1 expression and received consecutive treatments in the Affiliated Hospital of Qingdao University.

Results

TTF-1 expression was positive in 166 (79%) and negative in 43 (21%) patients who were reviewed. Moreover, there was no significant difference between the clinicopathologic features of TTF-1 positive and TTF-1 negative tumors. In the multivariable review, the overall survival of TTF-1 positive tumor patients was significantly longer than that of TTF-1 negative tumor patients [22.7 vs. 11.8 months (P<0.0001)], increasing the prognostic effect of Karnofsky performance status and receiving first-line chemotherapy or targeted therapy. Positive TTF-1 and negative TTF-1 patients receiving pemetrexed-based chemotherapy improved the duration of treatment compared to those receiving non-pemetrexed chemotherapy.

Conclusions

TTF-1 expression was associated with an improved survival in patients with advanced lung adenocarcinomas. Both patients, either TTF-1 positive or negative, could benefit from the first-line chemotherapy or pemetrexed treatment option. However, as discovered by our investigation, TTF-1 cannot forecast a portion of the lung adenocarcinomas that had a selective sensitivity to pemetrexed.

SOX2 mediates cisplatin resistance in small-cell lung cancer with downregulated expression of hsa-miR-340-5p

Background

This study is aimed to unravel the genetic factors associated with microRNA (miRNA) expression in regulating sex‐determining region Y‐box 2 (SOX2)‐mediated cisplatin resistance in small‐cell lung cancer (SCLC).

Methods

The relevance of SOX2 expression in SCLC was analyzed in a panel of SCLC cells by quantitative real‐time PCR (qPCR) and western blot (WB). We selected DMS114 cell line, in which SOX2 was amplified via lentiviral vector‐mediated transfection of the SOX2 genes and tested for the half‐maximal inhibitory concentration (IC₅₀) by MTS assay. High‐throughput sequencing and screening of differentially expressed miRNAs between SOX2‐overexpressing and normal control cells were performed. Finally, miRanda software was used to verify the miRNAs bound with SOX2 and qPCR was used to identify the expression of miRNAs which were binding with SOX2.

Results

Cisplatin‐resistant SOX2‐overexpressing DMS114 cell lines were successfully developed, showing a statistically significant increase in SOX2 expression by qPCR and WB. Our results showed a typically higher IC₅₀ value in SOX2‐overexpressing cells compared with the negative controls. The high‐throughput sequencing analysis revealed that 68 miRNAs were upregulated and 24 miRNAs were downregulated in the SOX2‐overexpressing cells. The 24 downregulated miRNAs were further verified. Of them, a cancer‐related miRNA, hsa‐miR‐340‐5p, showed a higher binding affinity with SOX2 in network regulation mapping, which was also found to be markedly downregulated under qPCR analysis.

Conclusion

We demonstrated that downregulated expression of hsa‐miR‐340‐5p may affect cisplatin resistance by mediating SOX2 expression in SCLC cells, which may provide a potential target for the therapy of chemoresistant SCLCs.

Thyroid Transcription Factor-1 Expression in Adenocarcinoma Lung and Its Association with Histomorphological Features

Objectives: Thyroid transcription factor-1 (TTF-1) expression is frequently associated with adenocarcinoma lung. This study was undertaken with the objectives to assess the expression of TTF-1 in non-small cell lung carcinoma (NSCLC) with adenocarcinoma phenotype and to evaluate the TTF-1 expression with clinicopathological and histomorphological features. Materials and Methods: This was a tertiary care hospital-based case series that included 250 cases of NSCLC. TTF-1 immunostaining along with a basic panel of immunohistochemistry markers was performed. The histomorphological analysis was done to compare the morphological features of TTF-1-positive versus TTF-1-negative cases. Results: TTF-1 was positive in 144 cases (57.6%), while 106 cases were negative for TTF-1. The M: F ratio in the TTF-1-positive group was 1:2, and the mean age of the cases that expressed TTF-1 was 48.5 years. The most common pattern in the TTF-1-positive group was loose clusters or singly dispersed cells (77.78%), followed by the acinar (54.86%) and solid pattern (42.36%). In the TTF-1-negative group, 86.79% of cases had singly dispersed cells or loose cohesive clusters, followed by a solid pattern in 50.94% cases. Conclusion: TTF-1 is a useful and reliable marker for pulmonary adenocarcinoma. TTF-1 expression does not have any association with the patterns and degree of differentiation evident in the tumor.

Comparing clinicopathological features and prognosis of primary pulmonary invasive mucinous adenocarcinoma based on computed tomography findings

Objective

To evaluate the relationship between clinicopathologic characteristics and prognosis in patients with invasive mucinous adenocarcinoma (IMA) of the lung.

Methods

A total of 68 patients who underwent surgical resection for primary lung IMA were reviewed during the period of 2009 and 2017. Tumors were classified as solitary-type or pneumonic-type according to the computed tomography (CT) findings. Cox proportional hazards model was used to assess the effects of clinicopathological characteristics on univariate and multivariable analyses of disease-free survival (DFS).

Results

Solitary-type was found in 54 patients, while pneumonic-type was found in 14 patients. The patients’ age varied between 56 and 68 years (patients’ median age was 61 years). Besides, 50 patients had T1/T2 tumor stage (73.5%). Compared with solitary-type, higher T stage, N stage, and pathological stage (P < 0.001) were found in pneumonic-type. Moreover, the survival analysis showed that the pneumonic-type had a significantly poorer DFS compared with solitary-type (P = 0.004). Univariate analysis showed that pneumonic pattern on CT scan, T stage, pathologic stage, and thyroid transcription factor-1 (TTF-1) were significant predictive factors of survival (P = 0.011, 0.014, 0.013, 0.029, respectively). Multivariate analysis further indicated that pneumonic-type was the only independent prognostic factor for poor survival [hazard ratio (HR) = 6.764, 95% confidence interval (CI): 1.563–29.269, P = 0.011].

Conclusions

Based on CT findings, the solitary-type IMA is associated with a lower stage and better prognosis compared with the pneumonic-type IMA.

Prognostic Value of Thyroid Transcription Factor-1 Expression in Patients with Advanced Lung Adenocarcinoma

BACKGROUND/AIM

The prognostic role of thyroid transcription factor-1 (TTF1) in advanced lung cancer is not clearly established. The present study aimed to evaluate the associations between clinicopathological characteristics, TTF1 expression, and overall survival (OS) of patients with advanced lung adenocarcinoma.

MATERIALS AND METHODS

One hundred and seventy-two patients were enrolled in this retrospective study. OS was assessed according to immunohistochemical TTF1 expression in lung adenocarcinoma tissue, age, gender, performance status (PS), smoking history and status, disease stage, tumor differentiation, epidermal growth factor receptor (EGFR) mutation and EGFR tyrosine kinase inhibitor (TKI) treatment status.

RESULTS

The OS time was longer (p<0.001) for patients with TTF1 expression than for patients without TTF1 expression (13.0 vs. 5.0 months, respectively). A multivariate analysis confirmed that worse PS [hazard ratio (HR)=2.13, p<0.001], poor histological differentiation (HR=2.02, p=0.001), wild-type EGFR status (HR=3.08, p<0.001) and negative TTF1 expression (HR=1.97, p=0.001) were independent predictors of worse prognosis.

CONCLUSION

TTF1 expression is an independent predictor of survival of patients with advanced lung adenocarcinoma.

Significance of the epidermal growth factor receptor mutation status and differences among molecular subgroups in surgically resected lung microinvasive adenocarcinoma

Lung microinvasive adenocarcinoma (MIA) is a newly-defined subtype of early stage non-small cell lung cancer (NSCLC). However, its epidermal growth factor receptor (EGFR) mutation status and clinical significance remain unclear. The present study aimed to determine EGFR mutation characteristics and identify their significance in patients with resected lung MIA. The present study also analyzed clinicopathological differences between EGFR molecular subgroups defined as 19Del and L858R. The present study examined EGFR mutations in 79 consecutive lung MIA resection specimens and compared the differences in clinicopathological features between the EGFR wild-type and mutation groups, as well as between the 19Del and L858R subgroups. EGFR mutations were detected in 60 (75.95%) tumors. The most common mutations were 19Del (28 cases; 35.44%) and L858R (30 cases; 37.97%). Two patients harbored rare mutations and one of them had a concomitant double mutation. EGFR mutations were significantly associated with microinvasion component, thyroid transcription factor 1 (TTF-1) expression, intratumoral fibrosis and inflammatory cell infiltration. Subgroup evaluation indicated that there was a significant association between 19Del and tumor size, maximum diameter of microinvasion, presence of intratumoral fibrosis and inflammatory cell infiltration. Similar associations were observed for the L858R subgroup, and L858R was associated with TTF-1 expression. In particular, 19Del occurred more frequently in MIA with a smaller size, with a smaller microinvasive area, without TTF-1 expression, and lacking intratumoral fibrosis and inflammatory cell infiltration. By contrast, L858R was detected more frequently in MIA with entirely different tumor features. In conclusion, the results of the present study indicated that surgically resected MIA cases harboring different EGFR gene statuses exhibit distinct clinicopathological features. Significant differences in pathological features associated with the tumor microenvironment were identified in MIA with 19Del or L858R mutations. Therefore, the present study proposed that MIA should be classified into molecular subgroups based on EGFR mutation subtypes. The molecular sub-classification should be taken into account for prognostic evaluation and clinical management of MIA.

FoxA1 and FoxA2 drive gastric differentiation and suppress squamous identity in NKX2-1-negative lung cancer

Changes in cancer cell identity can alter malignant potential and therapeutic response. Loss of the pulmonary lineage specifier NKX2-1 augments the growth of KRAS-driven lung adenocarcinoma and causes pulmonary to gastric transdifferentiation. Here, we show that the transcription factors FoxA1 and FoxA2 are required for initiation of mucinous NKX2-1-negative lung adenocarcinomas in the mouse and for activation of their gastric differentiation program. Foxa1/2 deletion severely impairs tumor initiation and causes a proximal shift in cellular identity, yielding tumors expressing markers of the squamocolumnar junction of the gastrointestinal tract. In contrast, we observe downregulation of FoxA1/2 expression in the squamous component of both murine and human lung adenosquamous carcinoma. Using sequential in vivo recombination, we find that FoxA1/2 loss in established KRAS-driven neoplasia originating from SPC-positive alveolar cells induces keratinizing squamous cell carcinomas. Thus, NKX2-1, FoxA1 and FoxA2 coordinately regulate the growth and identity of lung cancer in a context-specific manner.

Prognostic Impact of TTF-1 Expression in Non-Squamous Non-Small-Cell Lung Cancer: A Meta-Analysis

Thyroid transcription factor-1 (TTF-1) is overexpressed in up to 95% of primary lung adenocarcinoma while negative for almost all squamous cell carcinomas. TTF-1 expression has been investigated as a prognostic factor in non-small-cell lung cancer (NSCLC) with conflicting results. We conducted this meta-analysis to gain a better insight into the prognostic role of TTF-1 in patients only with non-squamous (non-SQ) NSCLC. A systematic computerized search of the electronic databases including PubMed, PMC, EMBASE, Web of Science, and Cochrane Library was performed. From 21 studies, 6,451 patients were included in the combined analysis of hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival. Compared with patients with non-SQ NSCLC showing negative TTF-1 expression, those with tumors harboring TTF-1 overexpression had significantly better survival (HR = 0.49, 95% CI: 0.42-0.57, p < 0.00001). Subgroup analyses revealed that TTF-1 expression significantly correlated with a better prognosis in stage I (HR = 0.65, 95% CI: 0.50-0.84, p = 0.0008) as well as stage III-IV non-SQ NSCLC (HR = 0.38, 95% CI: 0.29-0.49, p < 0.00001). In conclusion, this meta-analysis demonstrates that TTF-1 overexpression is a favorable prognostic factor in patients with non-SQ NSCLC. The subgroup analyses indicate that TTF-1 is a good prognostic marker for survival not only in early-stage but also in advanced non-SQ NSCLC.

TTF-1/Nkx2.1 functional connection with mutated EGFR relies on LRIG1 and β-catenin pathways in lung cancer cells

In non-small lung cancer, the expression of the transcription factor TTF-1/Nkx2.1 correlates with the presence of EGFR mutations, therefore TTF-1/Nkx2.1 expression is used to optimize an EGFR testing strategy and to guide clinical treatment. We investigate the molecular mechanisms underlying the functional connection between EGFR and TTF-1/Nkx2.1 gene expression in lung adenocarcinoma. Using the H1975 cell line as a non-small cell lung cancer model system and short hairpin RNA, we have selected clones with TTF-1/Nkx2.1 silenced expression. We have found that Leucine-rich immunoglobulin repeats-1 (LRIG1) gene is a direct target of TTF-1/Nkx2.1 and the transcription factor binding to the LRIG1 genomic sequence inhibits its gene expression. In TTF-1/Nkx2.1 depleted clones, we have found high levels of LRIG1 and decreased presence of EGFR protein. Furthermore, in TTF-1/Nkx2.1 depleted clones we detected a reduced β-catenin level and we provide experimental evidence indicating that TTF-1/Nkx2.1 gene expression is regulated by β-catenin. Published studies indicate that LRIG1 triggers EGFR degradation and that mutated EGFR induces β-catenin activity. Hence, with the present study we show that mutated EGFR, enhancing β-catenin, stimulates TTF-1/Nkx2.1 gene expression and, at the same time, TTF-1/Nkx2.1, down-regulating LRIG1, sustains EGFR pathway. Therefore, LRIG1 and β-catenin mediate the functional connection between TTF-1/Nkx2.1 and mutated EGFR.

TTF-1 and EGFR expression are related to EGFR mutation in lung adenocarcinoma

Thyroid transcription factor-1 (TTF-1) is routinely used in the diagnosis of lung carcinoma and the subclassification of non-small cell lung cancer (NSCLC) in combination with other markers. The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are particularly effective in NSCLC patients harboring active EGFR mutations. EGFR protein is a poor prognostic factor for NSCLC patients. The relationship between TTF-1 expression and EGFR mutation and EGFR expression has not been well documented. The aim of this study was to investigate the relationship between TTF-1 and EGFR expression and mutation, and the clinical significance in lung adenocarcinoma. We analyzed TTF-1 expression, EGFR expression and mutation in 213 cases of lung adenocarcinoma. TTF-1 and EGFR expression levels were detected by immunohistochemical staining with monoclonal antibodies. EGFR mutations in exon 18, 19, 20 and 21 were assayed by the scorpion amplification refractory mutation system (ARMS) method. Forty-eight patients with EGFR mutations in exon 19 or 21 were detected from 91 patients with TTF-1 strong positive expression (3+) (52.74%), and 35 patients were detected with either exon 19 or 21 mutations from 54 patients with both TTF1 and EGFR positive expression (64.81%). Our data indicate that TTF-1 expression was positively related to EGFR mutation (P < 0.001) and EGFR expression (P < 0.001). EGFR expression level was positively related to its mutation (P = 0.003). These results indicate TTF-1 and EGFR positive lung adenocarcinomas frequently harbor EGFR mutations.

Promoter-Operating Targeted Expression of Gene Therapy in Cancer: Current Stage and Prospect

The technique of targeted expression of interesting genes, including distinct delivery systems and specific gene promoter-operating expression, is an important strategy for gene therapy against cancers. Up to now, extensive literature documented the efficacy of distinct delivery systems, such as the liposome system, nano-particle system, polyetherimide (PEI) system, and so on, in cancer gene therapy. However, a related document on the potential value of using a specific gene promoter, such as a tumor suppressor, in cancer gene therapy was still scary. The main obstacle might be that the selection of an ideal gene promoter to operate interesting gene expression in cancer gene therapy is still not fully understood. Therefore, many efforts need to be done in order to make it a real power tool for the human clinical treatment of cancer patients. The purpose of this review is to clarify the current state and some problematics in development of promoter-operating targeted expression of interesting genes and highlight its potential in cancer gene therapy.

Phosphorylation of glutaminase by PKCε is essential for its enzymatic activity and critically contributes to tumorigenesis

Glutamine metabolism plays an important role in cancer development and progression. Glutaminase C (GAC), the first enzyme in glutaminolysis, has emerged as an important target for cancer therapy and many studies have focused on the mechanism of enhanced GAC expression in cancer cells. However, little is known about the post-translational modification of GAC. Here, we report that phosphorylation is a crucial post-translational modification of GAC, which is responsible for the higher glutaminase activity in lung tumor tissues and cancer cells. We identify the key Ser314 phosphorylation site on GAC that is regulated by the NF-κB-PKCε axis. Blocking Ser314 phosphorylation by the S314A mutation in lung cancer cells inhibits the glutaminase activity, triggers genetic reprogramming, and alleviates tumor malignancy. Furthermore, we find that a high level of GAC phosphorylation correlates with poor survival rate of lung cancer patients. These findings highlight a previously unappreciated mechanism for activation of GAC by phosphorylation and demonstrate that targeting glutaminase activity can inhibit oncogenic transformation.

Prognostic relevance of TTF-1 expression in stage I adenocarcinoma

Tyroid transcription factor-1 (TTF-1) motivates the differentiation and development of bronchioloalveolar cells. The association of TTF-1 expression with prognosis in stage I adenocarcinoma is unclear. This study enrolled patients with resected stage I pulmonary adenocarcinoma who had TTF-1 immunostaining. All the corresponding clinicopathologic data including sex, age, smoking history, pathologic T stage, pathologic disease stage, surgical procedure, subtypes, follow-up records and adjuvant chemotherapy were investigated. Totally, 126 adenocarcinomas with TTF-1− and 2687 adenocarcinomas with TTF-1+ were subjected to the study. Among adenocarcinomas with TTF-1−, the major subtype was acinar-predominant adenocarcinomas, followed by invasive mucinous and papillary subtypes while acinar, papillary and minimally invasive adenocarcinoma were in the majority among adenocarcinomas with TTF-1+. The status of TTF-1 expression was not a significant factor for relapse-free survival (RFS) and overall survival (OS). Furthermore, there was no survival difference between the two groups (RFS: p = 0.2474; OS: p = 0.1480). When confined to stage IB adenocarcinomas with TTF-1−, whether received adjuvant chemotherapy made no difference to RFS and OS (RFS: p = 0.2707; OS: p = 1.000), as was the case in stage IB adenocarcinomas with TTF-1+ (RFS: p = 0.9161; OS: p = 0.1100). Within follow-up period, there was significant difference in post-recurrence survival (PRS) for TTF-1− patients compared with those TTF-1+ patients (Log-rank p = 0.0113). However, regarding to the recurrence site, there was no difference between TTF-1− patients and TTF-1+ patients in patients with stage I adenocarcinoma (p = 0.771) In conclusion, there is no significant difference in RFS and OS between TTF-1− group and TTF-1+ group, but TTF-1 negative adenocarcinoma has significantly worse PFS in patients with stage I adenocarcinoma. Moreover, chemotherapeutic efficacy between TTF-1+ and TTF-1− stage IB adenocarcinomas did not differ.

Reaching the limits of prognostication in non-small cell lung cancer: an optimized biomarker panel fails to outperform clinical parameters

Numerous protein biomarkers have been analyzed to improve prognostication in non-small cell lung cancer, but have not yet demonstrated sufficient value to be introduced into clinical practice. Here, we aimed to develop and validate a prognostic model for surgically resected non-small cell lung cancer. A biomarker panel was selected based on (1) prognostic association in published literature, (2) prognostic association in gene expression data sets, (3) availability of reliable antibodies, and (4) representation of diverse biological processes. The five selected proteins (MKI67, EZH2, SLC2A1, CADM1, and NKX2-1 alias TTF1) were analyzed by immunohistochemistry on tissue microarrays including tissue from 326 non-small cell lung cancer patients. One score was obtained for each tumor and each protein. The scores were combined, with or without the inclusion of clinical parameters, and the best prognostic model was defined according to the corresponding concordance index (C-index). The best-performing model was subsequently validated in an independent cohort consisting of tissue from 345 non-small cell lung cancer patients. The model based only on protein expression did not perform better compared to clinicopathological parameters, whereas combining protein expression with clinicopathological data resulted in a slightly better prognostic performance (C-index: all non-small cell lung cancer 0.63 vs 0.64; adenocarcinoma: 0.66 vs 0.70, squamous cell carcinoma: 0.57 vs 0.56). However, this modest effect did not translate into a significantly improved accuracy of survival prediction. The combination of a prognostic biomarker panel with clinicopathological parameters did not improve survival prediction in non-small cell lung cancer, questioning the potential of immunohistochemistry-based assessment of protein biomarkers for prognostication in clinical practice.

Roles of Thyroid Transcription Factor 1 in Lung Cancer Biology

Thyroid transcription factor 1 (TTF-1 or NKX2-1) is a transcription factor of fundamental importance in driving lung maturation and morphogenesis. In the last decade, scientists began to appreciate the functional roles of TTF-1 in lung tumorigenesis. This movement was triggered by the discoveries of genetic alterations of TTF-1 in the form of gene amplification in lung cancer. Many downstream target genes of TTF-1 relevant to the lung cancer biology of TTF-1 have been documented. One of the most surprising findings was that TTF-1 may exhibit either pro- or antitumorigenic activities, an outcome with the complexity exceeding the original anticipation purely based on the fact that TTF-1 undergoes gene amplification in lung cancer. In the coming decade, we believe, we will witness additional surprises as the research exploring the cancer roles of TTF-1 progresses.

The Utility of Thyroid Transcription Factor 1 (TTF-1), Napsin A, Excision Repair Cross-Complementing 1 (ERCC1), Anaplastic Lymphoma Kinase (ALK) and the Epidermal Growth Factor Receptor (EGFR) Expression in Small Biopsy in Prognosis of Patients with Lung Adenocarcinoma - A Retrograde Single-Center Study from Croatia

Background

The present study was carried out in order to evaluate our institutional experience with small biopsy in diagnosis and molecular testing of lung adenocarcinoma. Few specific and predictive markers have been evaluated and correlated with clinicopathologic characteristics and survival in patients with lung adenocarcinoma who received platinum-based chemotherapy. There have not been such reports from Croatia.

Material/Methods

A total of 142 cases of lung adenocarcinoma were retrospectively investigated in small biopsies for the immunohistochemical expression of TTF-1, napsin A, ERCC1, ALK, and the EGFR mutation by real-time polymerase chain reaction (rtPCR).

Results

TTF-1, napsin A, and ERCC1 expression was found in 81%, 78%, and 69% of patients, respectively, and the expressions were not significantly associated with subtype. Expression of ALK was found in 4% and EGFR mutation in 10% of patients. Exon 19 deletions were the most common. Longer survival was significantly associated with TTF-1 positivity (p=0.007) and napsin A positivity (p=0.026). Higher relative risk of death significantly correlated with positive expression of ERCC1 (p=0.041).

Conclusions

Positive TTF-1 and napsin A expressions in lung adenocarcinoma tissues were useful diagnostic and favorable prognostic parameters. Positive ERCC1 expression was identified as a negative prognostic marker in patients treated with platinum-based chemotherapy. The percentages of EGFR and ALK mutations corresponded to those in previously published reports for Caucasians.

Targeted Expression of miR-7 Operated by TTF-1 Promoter Inhibited the Growth of Human Lung Cancer through the NDUFA4 Pathway

Targeted expression of gene technique is an important therapeutic strategy for lung cancer. MicroRNA-7 has been well documented as a promising tumor suppressor but never been test in specific gene-promoter-targeted expression in cancer gene therapy. Here, we first evaluated the efficacy of miR-7 expression operated by the promoter of TTF-1, a lineage-specific oncogene in lung cancer, in vitro using an eukaryotic vector of TTF-1-promoter-operated expression of miR-7 (termed as p-T-miR-7). Interestingly, using a nude mice model, the growth and metastasis of human lung cancer cells in vivo were significantly reduced in remote hypodermic injection of the p-T-miR-7 group, accompanied by increased expression of miR-7 and reduced transduction of the Akt and Erk pathway in situ. Mechanism aspect, global gene expression analysis showed that downregulation of NDUFA4, a novel target of miR-7, contributed to the effects of miR-7 expression operated by TTF-1 promoter on the growth and metastasis of human lung cancer cells, as well as altered transduction of the Akt and Erk pathway. Finally, there was no significant difference in weight or histopathology of other organs. These data provided a basis for development of novel modality of miRNA-based targeted expression therapy against clinical lung cancer.

An Analysis of EGFR Mutations among 1506 Cases of Non-Small Cell Lung Cancer Patients in Guangxi, China

An association between epidermal growth factor receptor (EGFR) and clinical characteristics of non-small cell lung cancer (NSCLC) was reported ten years ago. In addition, a different type of relationship was seen in different ethic races. However, the relationship between these factors is not well understood in the Guangxi province. Up to now, there are only very limited data on the association of TTF1/EGFR protein positivity and EGFR mutation status in NSCLC. This study aims to investigate the role of EGFR gene mutation status on the clinical characteristics and the relationship with TTF-1/EGFR protein positivity of patients with NSCLC in Guangxi, China. 1506 samples from different patients with NSCLC were detected by amplification refractory mutation system for 29 hotspot mutations. Analysis of the relationship between clinical characteristics and EGFR mutation status was performed by using the crosstabs Chi-square and SPSS 21.0 software. Of 1506 samples, 537 (35.7%) revealed tyrosine kinase inhibitor (TKI) sensitive EGFR mutations with 27 (1.8%) cases harboring TKI resistant EGFR mutations or union co-existing EGFR-TKIs sensitive mutations. EGFR-TKIs sensitive mutations were not significantly associated with age and TNM-M stage (P = 0.863; P = 0.572, respectively). However, they were significantly associated with p-stage, TNM-T stage and TNM-N stage (P = 0.011, P < 0.001, P = 0.036, respectively). Immunohistochemical studies revealed that TTF-1 and EGFR protein expression level were all associated with EGFR mutation status (P < 0.001, P = 0.002, respectively). Of the 537 EGFR-TKIs sensitive mutation cases, the rates of exon 19-del, 18 G719X point, exon 21 L858R and L861Q points were 54.6, 0.9, 42.3 and 0.9%, respectively. EGFR TKI-sensitive mutations commonly occur in female, non-smoking and adenocarcinoma patients. The p-stage, TNM-T stage, TNM-N stage, EGFR and TTF-1 protein expression levels have close relationships with EGFR mutation status.

Clinicopathological and Survival Analysis of Japanese Patients with Resected Non-Small-Cell Lung Cancer Harboring NKX2-1, SETDB1, MET, HER2, SOX2, FGFR1, or PIK3CA Gene Amplification

INTRODUCTION

Gene amplification is an important genetic change in cancer cells. We investigated the prevalence, clinicopathological characteristics, and prognostic value of NKX2-1 (also known as TTF-1), SETDB1, MET, HER2, SOX2, FGFR1, and PIK3CA amplification in Japanese patients with non-small-cell lung cancer (NSCLC).

METHODS

The copy numbers of the seven above-mentioned genes were assessed using fluorescence in situ hybridization in a tissue microarray containing 282 surgically resected NSCLC specimens (164 adenocarcinoma [AC], 99 squamous cell carcinoma [SCC], and 19 others). Clinicopathological information were obtained from the medical records.

RESULTS

NKX2-1, SETDB1, MET, HER2, SOX2, FGFR1, and PIK3CA gene amplification were observed in 30 of 277 (10.8%), 16 of 280 (5.7%), 38 of 278 (13.7%), 8 of 270 (3.0%), 34 of 278 (12.2%), 18 of 282 (6.4%), and 53 of 278 (19.1%) cases, respectively. Coamplification was detected in 16 of 156 (10.3%) AC patients and 35 of 93 (37.6%) SCC patients (p < 0.0001). NKX2-1 amplification was significantly related to an AC histology (p = 0.004), whereas SOX2, FGFR1, and PIK3CA amplifications were related to a SCC histology (p < 0.0001). Within the ACs, NKX2-1 and SETDB1 amplifications were markers of a shorter survival period. A multivariate Cox proportional hazards model revealed that NKX2-1 amplification was an independent predictor of poor survival (hazard ratio, 2.938; 95% confidence interval, 1.434-6.022; p = 0.003). Coamplification had impact on patient outcome in AC but not in entire NSCLC and SCC.

CONCLUSIONS

The amplification status differed among the histological types of NSCLC. NKX2-1 amplification was an independent and the most practically important predictor of a poor prognosis among Japanese patients with AC.

Negative Thyroid Transcription Factor 1 Expression Defines an Unfavorable Subgroup of Lung Adenocarcinomas

INTRODUCTION

Thyroid transcription factor 1 (TTF1) is a master regulator of pulmonary differentiation that is downregulated in a subset of lung adenocarcinoma, of which the clinicopathologic characteristics were not fully clarified.

METHODS

One thousand forty-two lung adenocarcinoma patients who underwent surgery were investigated for clinic characteristics, histologic subtyping, and spectrum of well-identified driver mutations. TTF1 expression was correlated with these clinicopathologic factors and survival.

RESULTS

Compared with TTF1 positive (TTF1+) patients, the 133 negative individuals (12.8%, TTF1-) were more likely to be male (p = 0.006) and heavy smokers (p = 0.002) who had larger tumor size (p < 0.001) and more advanced disease stage (p < 0.001). TTF1- presented more in solid and invasive mucinous-predominant carcinomas (both p < 0.001), whereas TTF1+ was identified in 100% patients with adenocarcinoma in situ, minimally invasive and lepidic-predominant adenocarcinomas. The TTF1- tumors harbored the known driver mutations in significantly low frequency compared with TTF1+ adenocarcinomas (57.8% versus 78.1%, p < 0.001), especially in epidermal growth factor receptor (EGFR) mutations (37.6% versus 60.7%, p < 0.001). There was no significant difference in recurrence-free survival between the TTF1- and TTF1+ patients, either for the whole cohort or stratified by pathologic stage, or among the driver mutation-defined subsets. However, recurrence of multiple metastases was more likely to occur in patients with TTF1- adenocarcinomas (88.1% versus 32.4%, p < 0.001). Multivariate analysis revealed that TTF1- independently predicted both poor postrecurrence survival (hazard ratio = 1.664; 95% confidence interval , 1.097-2.524; p = 0.017) and unfavorable overall survival (hazard ratio = 1.553; 95% confidence interval , 1.013-2.381; p = 0.043).

CONCLUSIONS

TTF1- correlated with solid and invasive mucinous subtypes of lung adenocarcinoma and lower frequency of EGFR mutations. It defines a subgroup of lung adenocarcinomas with unfavorable outcomes.

Thyroid Transcription Factor 1 Reprograms Angiogenic Activities of Secretome

Through both gain- and loss-of-TTF-1 expression strategies, we show that TTF-1 positively regulates vascular endothelial growth factor (VEGF) and that the VEGF promoter element contains multiple TTF-1-responsive sequences. The major signaling receptor for VEGF, i.e VEGFR2, also appears to be under a direct and positive regulation of TTF-1. The TTF-1-dependent upregulation of VEGF was moderately sensitive to rapamycin, implicating a partial involvement of mammalian target of rapamycin (mTOR). However, hypoxia did not further increase the secreted VEGF level of the TTF-1⁺ lung cancer cells. The TTF-1-induced VEGF upregulation occurs in both compartments (exosomes and exosome-depleted media (EDM)) of the conditioned media. Surprisingly, the EDM of TTF-1⁺ lung cancer cells (designated EDM-TTF-1⁺) displayed an anti-angiogenic activity in the endothelial cell tube formation assay. Mechanistic studies suggest that the increased granulocyte-macrophage colony-stimulating factor (GM-CSF) level in the EDM-TTF-1⁺ conferred the antiangiogenic activities. In human lung cancer, the expression of TTF-1 and GM-CSF exhibits a statistically significant and positive correlation. In summary, this study provides evidence that TTF-1 may reprogram lung cancer secreted proteome into an antiangiogenic state, offering a novel basis to account for the long-standing observation of favorable prognosis associated with TTF-1⁺ lung adenocarcinomas.

Prognostic implications of immunohistochemistry markers for EGFR-TKI therapy in Chinese patients with advanced lung adenocarcinoma harboring EGFR mutations

Background

Epidermal growth factor receptor (EGFR) mutations in non-small-cell lung cancer predict dramatic clinical responses to tyrosine kinase inhibitor (TKI) treatment. The conclusion on EGFR mutation-specific antibodies by immunohistochemistry (IHC) is not consistent. We evaluated the clinical availability of EGFR mutation-specific antibodies, investigating the prediction role of mutant EGFRs and other IHC markers in TKI therapy in patients with advanced lung adenocarcinoma.

Materials and methods

We analyzed 637 primary lung adenocarcinomas from an unselected Chinese population. For IHC, antibodies against EGFR exon 19 E746_A750 deletions, exon 21 L858R mutations, thyroid transcription factor-1 (TTF-1), and Napsin-A were applied. Positivity was defined as staining score >0.

Results

Specificities of E746_A750 and L858R antibodies were 99.6% and 99.3%, while sensitivities were 86.0% and 82.7%, respectively. Tumors with Napsin-A positivity, TTF-1 positivity, EGFR mutations, and lepidic pattern showed a lower marker of proliferation index (Ki67). Higher expression scores of mutant EGFR protein, TTF-1 positivity, lower Ki67 proliferation index, and lepidic pattern were associated with longer progression-free survival.

Conclusion

High scores of mutant EGFR, Napsin-A positivity, TTF-1 positivity, lower Ki67 index, and lepidic pattern were favorable predictors for TKI therapy in patients with advanced lung adenocarcinoma.

Lineage factors and differentiation states in lung cancer progression

Lung cancer encompasses a heterogeneous group of malignancies. Here we discuss how the remarkable diversity of major lung cancer subtypes is manifested in their transforming cell of origin, oncogenic dependencies, phenotypic plasticity, metastatic competence and response to therapy. More specifically, we review the increasing evidence that links this biological heterogeneity to the deregulation of cell lineage-specific pathways and the transcription factors that ultimately control them. As determinants of pulmonary epithelial differentiation, these poorly characterized transcriptional networks may underlie the etiology and biological progression of distinct lung cancers, while providing insight into innovative therapeutic strategies.

Sarcomatous transformation of EGFR and TP53 mutation-positive metastatic adenocarcinoma of the lungs, masquerading as a primary pleomorphic sarcoma of the proximal femur

We investigated a case of metastatic adenocarcinoma of the lungs at the left proximal femur, masquerading as a primary pleomorphic sarcoma. A 72-year-old woman presented with pain in her left thigh in conjunction with a mass that had been gradually growing over a few months. She was being treated with gefitinib for lung adenocarcinoma positive for the epidermal growth factor receptor (EGFR) mutation L858R, and had multiple bone metastases. The lung adenocarcinoma and metastases had stabilized with the treatment. The metastatic lesions in the bone had also received radiation; however, a tumor in the proximal femur kept growing despite treatment. A biopsy specimen from the proximal femur revealed the proliferation of spindle-shaped cells without an epithelial glandular component. The patient underwent en bloc resection of the proximal femur that was replaced by prosthesis. Histologically, the resected tumor was entirely composed of pleomorphic cells and tumor giant cells exhibiting no apparent glandular structures. Tumor cells were diffusely positive for p53 and focally positive for epithelial markers and EGFR, but were negative for thyroid transcription factor-1, suggesting an initial diagnosis of primary pleomorphic sarcoma. Genetic examination revealed mutations in EGFR and p53 that were of the same type as the lung tumor, leading to the final diagnosis of the femoral mass as a sarcomatous transformation of metastatic lung adenocarcinoma. However, secondary genetic alterations that might explain the acquired resistance to gefitinib could not be found in the proximal femoral tumor. The patient remains alive and the remaining lesions are well controlled.

Thyroid transcription factors in development, differentiation and disease

Identification of the thyroid transcription factors (TTFs), NKX2-1, FOXE1, PAX8 and HHEX, has considerably advanced our understanding of thyroid development, congenital thyroid disorders and thyroid cancer. The TTFs are fundamental to proper formation of the thyroid gland and for maintaining the functional differentiated state of the adult thyroid; however, they are not individually required for precursor cell commitment to a thyroid fate. Although knowledge of the mechanisms involved in thyroid development has increased, the full complement of genes involved in thyroid gland specification and the signals that trigger expression of the genes that encode the TTFs remain unknown. The mechanisms involved in thyroid organogenesis and differentiation have provided clues to identifying the genes that are involved in human congenital thyroid disorders and thyroid cancer. Mutations in the genes that encode the TTFs, as well as polymorphisms and epigenetic modifications, have been associated with thyroid pathologies. Here, we summarize the roles of the TTFs in thyroid development and the mechanisms by which they regulate expression of the genes involved in thyroid differentiation. We also address the implications of mutations in TTFs in thyroid diseases and in diseases not related to the thyroid gland.

Pulmonary adenocarcinoma: implications of the recent advances in molecular biology, treatment and the IASLC/ATS/ERS classification

A decade ago, lung cancer could conveniently be classified into two broad categories-either the small cell lung carcinoma (SCLC), or the non-small cell lung carcinoma (NSCLC), mainly to assist in further treatment related decision making. However, the understanding regarding the eligibility of adenocarcinoma histology for treatments with agents such as pemetrexed and bevacizumab made it a necessity for NSCLC to be classified into more specific sub-groups. Then, the availability of molecular targeted therapy with oral tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib not only further emphasized the need for accurate sub-classification of lung cancer, but also heralded the important role of molecular profiling of lung adenocarcinomas. Given the remarkable advances in molecular biology, oncology and radiology, a need for felt for a revised classification for lung adenocarcinoma, since the existing World Health Organization (WHO) classification of lung cancer, published in the year 2004 was mainly a pathological system of classification. Thus, there was a combined effort by the International Association for the Study of Lung Cancer (IASLC), the American Thoracic Society (ATS) and the European Respiratory Society (ERS) with an effort to inculcate newly established perspectives from clinical, molecular and radiological aspects in evolving a modern classification for lung adenocarcinomas. This review provides a summary of the recent advances in molecular biology and molecular targeted therapy with respect to lung adenocarcinoma. Also, a brief summation of the salient recommendations provided in the IASLC/ATS/ERS classification of lung adenocarcinomas is provided. Lastly, a discussion regarding the future prospects with lung adenocarcinoma is included.

The lung adenocarcinoma guidelines: what to be considered by surgeons

In 2011 the International Association for the Study of Lung Cancer (IASLC), the American Thoracic Society (ATS), and the European Respiratory Society (ERS), have proposed a new subclassification of lung adenocarcinomas. This new classification was founded on an evidence-based approach to a systematic review of 11,368 citations from the related literature. Validation has involved projects relating to histologic and cytologic analysis of small biopsy specimens, histologic subtyping, grading, and observer variation among expert pathologists. As enormous resources are being spent on trials involving molecular and therapeutic aspects of adenocarcinoma of the lung, the development of standardized criteria is of great importance and should help advance the field, increasing the impact of research, and improving patient care. This classification is needed to assist in determining patient therapy and predicting outcome. The 2011 IASLC/ATS/ERS adenocarcinoma classification can have an impact on TNM staging. It may help in comparing histologic characteristics of multiple lung adenocarcinomas to determine whether they are intrapulmonary metastases versus separate primaries. Use of comprehensive histologic subtyping along with other histologic characteristics has been shown to have good correlation with molecular analyses and clinical behavior. Also, it may be more meaningful clinically to measure tumor size in lung adenocarcinomas that have a lepidic component by using invasive size rather than total size to determine the size T factor.

Epidermal growth factor receptor (EGFR) mutations are exceptionally rare in thyroid transcription factor (TTF-1)-negative adenocarcinomas of the lung

Introduction

Approximately 70% of lung adenocarcinomas express TTF-1. EGFR mutations are present in 13-15% of Western adenocarcinoma patients. This paper investigates TTF1 as a negative predictor of mutant EGFR in lung adenocarcinomas.

Results

In the pilot cohort (N = 301) two of 224 specimens positive for EGFR mutations had negative TTF-1 expression (sensitivity 99.1%, 95% confidence interval (CI) 96.8-99.9%). Estimated negative predictive values (NPV) for EGFR mutation prevalence rates of 13% and 15% are 99.5% (95% credible interval (CRI) 98.6%-99.9%) and 99.4% (CRI – 98.4%-99.9%). For EGFR mutation rates of 13% and 15%, using validation cohort data (211 patients), the estimated NPVs were 97% (95% CRI 92%-99%) and 96% (95% CRI 91%-99%).

Methods

Formalin-fixed paraffin-embedded tumors from lung adenocarcinoma patients were analyzed for EGFR mutations by allele-specific PCR in the ‘pilot cohort’. TTF-1 status was documented as positive or negative. Negative predictive value (NPV) for a range of true prevalence of EGFR mutation (1%-50%) was estimated using Bayesian modeling. The hypothesis was validated in a separate ‘validation’ cohort using the same modeling.

Conclusion

An overwhelming majority of TTF-1 negative adenocarcinomas will be negative for EGFR mutations. This finding allows for earlier initiation of chemotherapy in newly diagnosed TTF-1 negative adenocarcinomas of the lung with stage IV disease.

Neurotrophin receptor TrkB promotes lung adenocarcinoma metastasis

Lung cancer is notorious for its ability to metastasize, but the pathways regulating lung cancer metastasis are largely unknown. An in vitro system designed to discover factors critical for lung cancer cell migration identified brain-derived neurotrophic factor, which stimulates cell migration through activation of tropomyosin-related kinase B (TrkB; also called NTRK2). Knockdown of TrkB in human lung cancer cell lines significantly decreased their migratory and metastatic ability in vitro and in vivo. In an autochthonous lung adenocarcinoma model driven by activated oncogenic Kras and p53 loss, TrkB deficiency significantly reduced metastasis. Hypoxia-inducible factor-1 directly regulated TrkB expression, and, in turn, TrkB activated Akt signaling in metastatic lung cancer cells. Finally, TrkB expression was correlated with metastasis in patient samples, and TrkB was detected more often in tumors that did not have Kras or epidermal growth factor receptor mutations. These studies demonstrate that TrkB is an important therapeutic target in metastatic lung adenocarcinoma.

Using multiplexed assays of oncogenic drivers in lung cancers to select targeted drugs

IMPORTANCE

Targeting oncogenic drivers (genomic alterations critical to cancer development and maintenance) has transformed the care of patients with lung adenocarcinomas. The Lung Cancer Mutation Consortium was formed to perform multiplexed assays testing adenocarcinomas of the lung for drivers in 10 genes to enable clinicians to select targeted treatments and enroll patients into clinical trials.

OBJECTIVES

To determine the frequency of oncogenic drivers in patients with lung adenocarcinomas and to use the data to select treatments targeting the identified driver(s) and measure survival.

DESIGN, SETTING, AND PARTICIPANTS

From 2009 through 2012, 14 sites in the United States enrolled patients with metastatic lung adenocarcinomas and a performance status of 0 through 2 and tested their tumors for 10 drivers. Information was collected on patients, therapies, and survival.

INTERVENTIONS

Tumors were tested for 10 oncogenic drivers, and results were used to select matched targeted therapies.

MAIN OUTCOMES AND MEASURES

Determination of the frequency of oncogenic drivers, the proportion of patients treated with genotype-directed therapy, and survival.

RESULTS

From 2009 through 2012, tumors from 1007 patients were tested for at least 1 gene and 733 for 10 genes (patients with full genotyping). An oncogenic driver was found in 466 of 733 patients (64%). Among these 733 tumors, 182 tumors (25%) had the KRAS driver; sensitizing EGFR, 122 (17%); ALK rearrangements, 57 (8%); other EGFR, 29 (4%); 2 or more genes, 24 (3%); ERBB2 (formerly HER2), 19 (3%); BRAF, 16 (2%); PIK3CA, 6 (<1%); MET amplification, 5 (<1%); NRAS, 5 (<1%); MEK1, 1 (<1%); AKT1, 0. Results were used to select a targeted therapy or trial in 275 of 1007 patients (28%). The median survival was 3.5 years (interquartile range [IQR], 1.96-7.70) for the 260 patients with an oncogenic driver and genotype-directed therapy compared with 2.4 years (IQR, 0.88-6.20) for the 318 patients with any oncogenic driver(s) who did not receive genotype-directed therapy (propensity score-adjusted hazard ratio, 0.69 [95% CI, 0.53-0.9], P = .006).

CONCLUSIONS AND RELEVANCE

Actionable drivers were detected in 64% of lung adenocarcinomas. Multiplexed testing aided physicians in selecting therapies. Although individuals with drivers receiving a matched targeted agent lived longer, randomized trials are required to determine if targeting therapy based on oncogenic drivers improves survival.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01014286.

Nullifying the CDKN2AB locus promotes mutant K-ras lung tumorigenesis

Lung cancer commonly displays a number of recurrent genetic abnormalities, and about 30% of lung adenocarcinomas carry activating mutations in the Kras gene, often concomitantly with inactivation of tumor suppressor genes p16(INK4A) and p14(ARF) of the CDKN2AB locus. However, little is known regarding the function of p15INK4B translated from the same locus. To determine the frequency of CDKN2AB loss in human mutant KRAS lung cancer, The Cancer Genome Atlas (TCGA) database was interrogated. Two-hit inactivation of CDKN2A and CDKN2B occurs frequently in patients with mutant KRAS lung adenocarcinoma. Moreover, p15INK4B loss occurs in the presence of biallelic inactivation of p16(INK4A) and p14(ARF), suggesting that p15INK4B loss confers a selective advantage to mutant KRAS lung cancers that are p16(INK4A) and p14(ARF) deficient. To determine the significance of CDKN2AB loss in vivo, genetically engineered lung cancer mouse models that express mutant Kras in the respiratory epithelium were utilized. Importantly, complete loss of CDKN2AB strikingly accelerated mutant Kras-driven lung tumorigenesis, leading to loss of differentiation, increased metastatic disease, and decreased overall survival. Primary mutant Kras lung epithelial cells lacking Cdkn2ab had increased clonogenic potential. Furthermore, comparative analysis of mutant Kras;Cdkn2a null with Kras;Cdkn2ab null mice and experiments with mutant KRAS;CDKN2AB-deficient human lung cancer cells indicated that p15INK4B is a critical tumor suppressor. Thus, the loss of CDKN2AB is of biologic significance in mutant KRAS lung tumorigenesis by fostering cellular proliferation, cancer cell differentiation, and metastatic behavior.

IMPLICATIONS

These findings indicate that mutant Kras;Cdkn2ab null mice provide a platform for accurately modeling aggressive lung adenocarcinoma and testing therapeutic modalities.

Napsin A is possibly useful marker to predict the tumorigenic potential of lung bronchiolo-alveolar hyperplasia in F344 rats

There are 2 types of bronchiolo-alveolar hyperplasia found in rat lungs. One is 'inflammatory hyperplasia' with a potential to recover in future with removal of the stimulating insult and the other is 'latent tumorigenic hyperplasia' as an independent preneoplastic lesion for adenocarcinoma. In the present experiment, we focused on rat lung bronchiolo-alveolar hyperplasia induced by 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), which decreases with time after induction and reverts to normal, or by N-bis(2-hydroxypropyl)nitrosamine (DHPN), with tumorigenic potential to progress to adenoma and adenocarcinoma. Though NNK is a typical carcinogen inducing lung adenocarcinoma in female A/J mice, the tumorigenic potential by NNK in rats is weak. Differences between hyperplasias induced by DHPN and by NNK were here examined immunohistochemically. Formalin fixed paraffin embedded lung samples with hyperplastic and inflammatory lesions were obtained from rats exposed to DHPN or NNK and from lung inflammation models induced with fine particles like CuO, NiO and quartz. The 19 markers were examined immunohistochemically. Napsin A, in the inflammatory lesions and hyperplasia induced by NNK, was positive for macrophages and secretions in the alveoli spaces but less so in the walls of the alveoli. In the proliferative lesions including hyperplasia induced by DHPN, strong positive staining for napsin A was observed in the walls of the alveoli. Thus high expression was suggested to be possibly useful for detecting tumorigenic potential of rat lung hyperplasia.

The complexity of thyroid transcription factor 1 with both pro- and anti-oncogenic activities

After the original identification of thyroid transcription factor 1 (TTF-1 or NKX2-1) biochemical activity as a transcriptional regulator of thyroglobulin in 1989, the bulk of the ensuing research has concentrated on elucidating the roles of NKX2-1 in the development of lung and thyroid tissues. Motivated by its specific expression pattern, pathologists adopted the NKX2-1 immunoreactivity to distinguish pulmonary from nonpulmonary nonthyroid adenocarcinomas. Interestingly, the concept of NKX2-1 as an active participant in lung tumorigenesis did not take hold until 2007. This minireview contrasts the recent advancements of NKX2-1-related observations primarily in the realm of pulmonary malignancies.

Gauging NOTCH1 Activation in Cancer Using Immunohistochemistry

Fixed, paraffin-embedded (FPE) tissues are a potentially rich resource for studying the role of NOTCH1 in cancer and other pathologies, but tests that reliably detect activated NOTCH1 (NICD1) in FPE samples have been lacking. Here, we bridge this gap by developing an immunohistochemical (IHC) stain that detects a neoepitope created by the proteolytic cleavage event that activates NOTCH1. Following validation using xenografted cancers and normal tissues with known patterns of NOTCH1 activation, we applied this test to tumors linked to dysregulated Notch signaling by mutational studies. As expected, frequent NICD1 staining was observed in T lymphoblastic leukemia/lymphoma, a tumor in which activating NOTCH1 mutations are common. However, when IHC was used to gauge NOTCH1 activation in other human cancers, several unexpected findings emerged. Among B cell tumors, NICD1 staining was much more frequent in chronic lymphocytic leukemia than would be predicted based on the frequency of NOTCH1 mutations, while mantle cell lymphoma and diffuse large B cell lymphoma showed no evidence of NOTCH1 activation. NICD1 was also detected in 38% of peripheral T cell lymphomas. Of interest, NICD1 staining in chronic lymphocytic leukemia cells and in angioimmunoblastic lymphoma was consistently more pronounced in lymph nodes than in surrounding soft tissues, implicating factors in the nodal microenvironment in NOTCH1 activation in these diseases. Among carcinomas, diffuse strong NICD1 staining was observed in 3.8% of cases of triple negative breast cancer (3 of 78 tumors), but was absent from 151 non-small cell lung carcinomas and 147 ovarian carcinomas. Frequent staining of normal endothelium was also observed; in line with this observation, strong NICD1 staining was also seen in 77% of angiosarcomas. These findings complement insights from genomic sequencing studies and suggest that IHC staining is a valuable experimental tool that may be useful in selection of patients for clinical trials.

Control of alveolar differentiation by the lineage transcription factors GATA6 and HOPX inhibits lung adenocarcinoma metastasis

Molecular programs that mediate normal cell differentiation are required for oncogenesis and tumor cell survival in certain cancers. How cell-lineage-restricted genes specifically influence metastasis is poorly defined. In lung cancers, we uncovered a transcriptional program that is preferentially associated with distal airway epithelial differentiation and lung adenocarcinoma (ADC) progression. This program is regulated in part by the lineage transcription factors GATA6 and HOPX. These factors can cooperatively limit the metastatic competence of ADC cells, by modulating overlapping alveolar differentiation and invasogenic target genes. Thus, GATA6 and HOPX are critical nodes in a lineage-selective pathway that directly links effectors of airway epithelial specification to the inhibition of metastasis in the lung ADC subtype.

Pulmonary large cell carcinoma lacking squamous differentiation is clinicopathologically indistinguishable from solid-subtype adenocarcinoma

CONTEXT

Pulmonary large cell carcinoma (LCC) includes tumors not readily diagnosed as adenocarcinoma (ADC) or squamous cell carcinoma on morphologic grounds, without regard to immunophenotype, according to the World Health Organization (WHO). This ambiguous designation may cause confusion over selection of mutation testing and directed therapies. Several groups have proposed the use of immunohistochemistry (IHC) to recategorize LCC as ADC or squamous cell carcinoma; however, it remains unclear if strictly defined LCCs are a clinicopathologically distinct lung tumor subset.

OBJECTIVE

To compare the pathologic, molecular, and clinical features of 2 morphologically similar tumors: solid-subtype ADC and LCC.

DESIGN

Tumors were included on the basis of solid growth pattern; tumors with squamous or neuroendocrine differentiation were excluded. Solid ADC (n = 42) and LCC (n = 57) were diagnosed by using WHO criteria (5 intracellular mucin droplets in ≥2 high-power fields for solid ADC) and tested for KRAS, EGFR, and ALK alterations.

RESULTS

Both solid ADC and LCC groups were dominated by tumors with "undifferentiated"-type morphology and both had a high frequency of thyroid transcription factor 1 expression. KRAS was mutated in 38% of solid ADCs versus 43% of LCCs (P = .62). One ALK-rearranged and 1 EGFR-mutated tumor were detected in the solid ADC and LCC groups, respectively. There were no significant differences in clinical features or outcomes; the prevalence of smoking in both groups was greater than 95%.

CONCLUSIONS

Other than a paucity of intracellular mucin, LCC lacking squamous or neuroendocrine differentiation is indistinguishable from solid-subtype ADC. We propose the reclassification of these tumors as mucin-poor solid adenocarcinomas.

Expression of the epithelial-mesenchymal transition-related proteins and their clinical significance in lung adenocarcinoma

Background

Epithelial-mesenchymal transition (EMT) is defined as switching of polarized epithelial cells to a migratory fibroblastoid phenotype. EMT is known to be involved in the progression and metastasis of various cancers. The aim was to evaluate that whether EMT-related proteins' alterations are associated with clinicopathological features and prognosis in lung adenocarcinoma.

Methods

The expression of EMT-related proteins including cytokeratin, E-cadherin, TTF-1, β-catenin, vimentin, Snail, Twist, CD44 was evaluated by immunohistochemistry using a tissue array method in the lung adenocarcinoma tissues of 95 patients. In addition, clinicopathological characteristics and survival were compared with the expression of EMT-related proteins.

Results

Loss of epithelial proteins and/or acquisition of the expression of mesenchymal proteins were observed in lung adenocarcinoma. These proteins’ alteration was associated with poor cell differentiation and poor patients’ outcome, respectively. Subjects were divided into two groups according to the number of EMT-related proteins’ alteration. A higher number of EMT-related proteins’ alteration was found to be significantly associated with unfavorable outcome. Multivariate analysis showed that a higher number of EMT-related proteins’ alteration was independently associated with poor prognosis.

Conclusions

The number of EMT-related proteins’ alteration is a significant prognostic marker to predict overall survival in patients with lung adenocarcinoma. The information generated will be valuable for the prognosis of patients with lung adenocarcinoma.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1007838329872974