Silencing of PINK1 represses cell growth, migration and induces apoptosis of lung cancer cells

PTEN induced putative kinase 1 (PINK1) has been found to be up-regulated, which promotes the proliferation and chemoresistance in lung cancer. Nevertheless, the role and detailed mechnisms of PINK1 in lung cancer have not been fully understood, which need to be further clarified. In this study, the resluts showed that silencing of PINK1 inhibited proliferation and blocked cell cycle of lung cancer cells. Furthermore, the apoptosis rate was enhanced by PINK1 suppression, as evidenced by increased protein levels of Bax, cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase (PARP), and decreased level of Bcl-2. The migration and invasion abilities were also restrained by PINK1 silencing. Silencing of PINK1 also resulted in oxygen species (ROS) overproduction and decreased mitochondrial membrane potential. Finally, suppression of PINK1 repressed the growth of xenograft tumor and induced apoptosis in tumor tissues in vivo. This study might lead to PINK1 kinase as a novel therapeutic target for lung cancer treatment.

SET1A-Mediated Mono-Methylation at K342 Regulates YAP Activation by Blocking Its Nuclear Export and Promotes Tumorigenesis

YAP, a key effector of Hippo pathway, is activated by its translocation from cytoplasm to nucleus to regulate gene expression and promote tumorigenesis. Although the mechanism by which YAP is suppressed in cytoplasm has been well-studied, how the activated YAP is sequestered in the nucleus remains unknown. Here, we demonstrate that YAP is a nucleocytoplasmic shuttling protein and its nuclear export is controlled by SET1A-mediated mono-methylation of YAP at K342, which disrupts the binding of YAP to CRM1. YAP mimetic methylation knockin mice are more susceptible to colorectal tumorigenesis. Clinically, YAP K342 methylation is reversely correlated with cancer survival. Collectively, our study identifies SET1A-mediated mono-methylation at K342 as an essential regulatory mechanism for regulating YAP activity and tumorigenesis.

Transcriptional Activation of Human GD3 Synthase (hST8Sia I) Gene in Curcumin-Induced Autophagy in A549 Human Lung Carcinoma Cells

Curcumin, a natural polyphenolic compound isolated from the plant Curcuma longa, is known to induce autophagy in various cancer cells, including lung cancer. In the present study, we also confirmed by LC3 immunofluorescence and immunoblotting analyses that curcumin triggers autophagy in the human lung adenocarcinoma A549 cell line. In parallel with autophagy induction, the gene expression of human GD3 synthase (hST8Sia I) responsible for ganglioside GD3 synthesis was markedly elevated in response to curcumin in the A549 cells. To investigate the transcriptional activation of hST8Sia I associated with the autophagy formation in curcumin-treated A549 cells, functional characterization of the 5′-flanking region of the hST8Sia I gene was carried out using the luciferase reporter assay system. Deletion analysis demonstrated that the -1146 to -646 region, which includes the putative c-Ets-1, CREB, AP-1, and NF-κB binding sites, functions as the curcumin-responsive promoter of hST8Sia I in A549 cells. The site-directed mutagenesis and chromatin immunoprecipitation assay demonstrated that the NF-κB binding site at -731 to -722 was indispensable for the curcumin-induced hST8Sia I gene expression in A549 cells. Moreover, the transcriptional activation of hST8Sia I by the curcumin A549 cells was strongly inhibited by compound C, an inhibitor of AMP-activated protein kinase (AMPK). These results suggest that curcumin controls hST8Sia I gene expression via AMPK signal pathway in A549 cells.

Toward innovative combinational immunotherapy: A systems biology perspective

The treatment of non-small-cell lung cancer (NSCLC) has advanced significantly in the last decades. Especially immune checkpoint inhibitors have shown inconceivable effect on enhancing host anti-tumor activity in NSCLC. However, the limitation of checkpoint blockade monotherapy seems unavoidable in most of the NSCLC patients and only ∼20% of them achieved response to monotherapy with immune checkpoint inhibitors. Thus combining immune checkpoint inhibitors with other agents with different action mechanisms holds a promise to revitalize NSCLC treatment, such as the combination of checkpoint inhibitors with angiogenesis inhibitors, or with chemotherapy, as well as the combination of two checkpoint inhibitors. Recently, various combinational strategies have been explored to setup promising combination regimens and to understand the action mechanisms. In this review, we summarize the suspected synergistic mechanisms of several combinational approaches by reviewing the available preclinical and clinical data. Then we discuss in light of the current knowledge of cancer biology and systems biology the important facets to be examined when setting up a framework for developing immunotherapy-based combination strategies.

Circulating tumor cells predict prognosis following secondline AZD 9291 treatment in EGFR-T790M mutant non-small cell lung cancer patients

PURPOSE

AZD9291 has been developed as third-generation epithermal growth factor receptor (EGFR)- tyrosine kinase inhibitor (TKI) with activities against T790M mutation. This study aimed to isolate and quantify the circulating tumor cells (CTCs) in non-small cell lung cancer (NSCLC) patients after first-line EGFR TKIs and investigate their role in providing prognostic information.

METHODS

Enrolled patients confirmed with EGFR T790M mutation received AZD9291 80 mg orally once daily as second-line treatment. Serial blood samples were taken at baseline (CTC-d0) and on day 28 (CTC-d28) following the initiation of AZD9291 for detection of CTCs using the Cell-Search system.

RESULTS

The CTC measurements were dichotomized as favorable (<5 CTCs) and unfavorable (≥5 CTCs) groups. Patients in the favorable group at baseline exhibited significantly longer median progression-free survival (PFS) compared with patients in the unfavorable group (9.3 vs. 6.5 months; p=0.0002). The PFS interval for patients in the favorable group on day 28 was 9.7 months, significantly longer than the median PFS time of 6.2 months achieved by patients in the unfavorable group (p=0.011). In univariate and multivariate analysis, CTC-d0 ≥5 vs CTC-d0=0-4 was significantly associated with poor PFS.

CONCLUSIONS

This is the first report over the presence of CTCs and their prognostic role in patients with EGFR T790M-positive NSCLC following disease progression on an EGFR TKI. The use of serial CTC evaluation as a surrogate biomarker needs further validation in larger samples of patients.

Exposure-response analysis of alectinib in crizotinib-resistant ALK-positive non-small cell lung cancer

PURPOSE

Alectinib is a selective and potent anaplastic lymphoma kinase (ALK) inhibitor that is active in the central nervous system (CNS). Alectinib demonstrated robust efficacy in a pooled analysis of two single-arm, open-label phase II studies (NP28673, NCT01801111; NP28761, NCT01871805) in crizotinib-resistant ALK-positive non-small-cell lung cancer (NSCLC): median overall survival (OS) 29.1 months (95% confidence interval [CI]: 21.3-39.0) for alectinib 600 mg twice daily (BID). We investigated exposure-response relationships from final pooled phase II OS and safety data to assess alectinib dose selection.

METHODS

A semi-parametric Cox proportional hazards model analyzed relationships between individual median observed steady-state trough concentrations (Ctrough,ss) for combined exposure of alectinib and its major metabolite (M4), baseline covariates (demographics and disease characteristics) and OS. Univariate logistic regression analysis analyzed relationships between Ctrough,ss and incidence of adverse events (AEs: serious and Grade ≥ 3).

RESULTS

Overall, 92% of patients (n = 207/225) had Ctrough,ss data and were included in the analysis. No statistically significant relationship was found between Ctrough,ss and OS following alectinib treatment. The only baseline covariates that statistically influenced OS were baseline tumor size and prior crizotinib treatment duration. Larger baseline tumor size and shorter prior crizotinib treatment were both associated with shorter OS. Logistic regression confirmed no significant relationship between Ctrough,ss and AEs.

CONCLUSION

Alectinib 600 mg BID provides systemic exposures at plateau of response for OS while maintaining a well-tolerated safety profile. This analysis confirms alectinib 600 mg BID as the recommended global dose for patients with crizotinib-resistant ALK-positive NSCLC.

Hybrid Capture-Based Comprehensive Genomic Profiling Identifies Lung Cancer Patients with Well-Characterized Sensitizing Epidermal Growth Factor Receptor Point Mutations That Were Not Detected by Standard of Care Testing

BACKGROUND

In our recent study, of cases positive for epidermal growth factor receptor (EGFR) exon 19 deletions using comprehensive genomic profiling (CGP), 17/77 (22%) patients with prior standard of care (SOC) EGFR testing results available were previously negative for exon 19 deletion. Our aim was to compare the detection rates of CGP versus SOC testing for well-characterized sensitizing EGFR point mutations (pm) in our 6,832-patient cohort.

MATERIALS AND METHODS

DNA was extracted from 40 microns of formalin-fixed paraffin-embedded sections from 6,832 consecutive cases of non-small cell lung cancer (NSCLC) of various histologies (2012-2015). CGP was performed using a hybrid capture, adaptor ligation-based next-generation sequencing assay to a mean coverage depth of 576×. Genomic alterations (pm, small indels, copy number changes and rearrangements) involving EGFR were recorded for each case and compared with prior testing results if available.

RESULTS

Overall, there were 482 instances of EGFR exon 21 L858R (359) and L861Q (20), exon 18 G719X (73) and exon 20 S768I (30) pm, of which 103 unique cases had prior EGFR testing results that were available for review. Of these 103 cases, CGP identified 22 patients (21%) with sensitizing EGFR pm that were not detected by SOC testing, including 9/75 (12%) patients with L858R, 4/7 (57%) patients with L861Q, 8/20 (40%) patients with G719X, and 4/7 (57%) patients with S768I pm (some patients had multiple EGFR pm). In cases with available clinical data, benefit from small molecule inhibitor therapy was observed.

CONCLUSION

CGP, even when applied to low tumor purity clinical-grade specimens, can detect well-known EGFR pm in NSCLC patients that would otherwise not be detected by SOC testing. Taken together with EGFR exon 19 deletions, over 20% of patients who are positive for EGFR-activating mutations using CGP are previously negative by SOC EGFR mutation testing, suggesting that thousands of such patients per year in the U.S. alone could experience improved clinical outcomes when hybrid capture-based CGP is used to inform therapeutic decisions.

IMPLICATIONS FOR PRACTICE

This study points out that genomic profiling, as based on hybrid capture next-generation sequencing, can identify lung cancer patients with point mutation in epidermal growth factor receptor (EGFR) missed by standard molecular testing who can likely benefit from anti-EGFR targeted therapy. Beyond the specific findings regarding false-negative point mutation testing for EGFR, this study highlights the need for oncologists and pathologists to be cognizant of the performance characteristics of testing deployed and the importance of clinical intuition in questioning the results of laboratory testing.

Distinct Prognostic Values of Alcohol Dehydrogenase Family Members for Non-Small Cell Lung Cancer

BACKGROUND Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related death worldwide. The relationships of alcohol dehydrogenase (ADH) enzymes, encoded by the genes ADH1 (1A), ADH1B (ADH2), ADH1C (ADH3), ADH4, ADH5, ADH6, and ADH7, with NSCLC have not been studied. The aim of this study was to explore the associations between NSCLC prognosis and the expression patterns of ADH family members. MATERIAL AND METHODS The online resource Metabolic gEne RApid Visualizer was used to assess the expression patterns of ADH family members in normal and primary lung tumor tissues. The GeneMANIA plugin of Cytoscape software and STRING website were used to evaluate the relationships of the 7 ADH family members at the gene and protein levels. Gene ontology enrichment analysis and KEGG pathway analysis were performed using DAVID. The online website Kaplan-Meier Plotter was used to construct survival curves between NSCLC and ADH isoforms. RESULTS The prognosis of patients with high expression levels of the ADH1B, ADH1C, ADH4, and ADH5 genes was better than those with low expression in adenocarcinoma and all (containing adenocarcinoma and squamous cell cancer) histological types (all P<0.05). Low expression of ADH7 was associated with a better prognosis in patients with both the adenocarcinoma and squamous cell cancer histological types (P=9e-05). Moreover, expression of ADH family members was associated with smoking status, clinical stage, and chemotherapy status. CONCLUSIONS ADH1B, ADH1C, ADH4, ADH5, and ADH7 appear to be useful biomarkers for the prognosis of NSCLC patients.

Overexpression of the base excision repair NTHL1 glycosylase causes genomic instability and early cellular hallmarks of cancer

Base excision repair (BER), which is initiated by DNA N-glycosylase proteins, is the frontline for repairing potentially mutagenic DNA base damage. The NTHL1 glycosylase, which excises DNA base damage caused by reactive oxygen species, is thought to be a tumor suppressor. However, in addition to NTHL1 loss-of-function mutations, our analysis of cancer genomic datasets reveals that NTHL1 frequently undergoes amplification or upregulation in some cancers. Whether NTHL1 overexpression could contribute to cancer phenotypes has not yet been explored. To address the functional consequences of NTHL1 overexpression, we employed transient overexpression. Both NTHL1 and a catalytically-dead NTHL1 (CATmut) induce DNA damage and genomic instability in non-transformed human bronchial epithelial cells (HBEC) when overexpressed. Strikingly, overexpression of either NTHL1 or CATmut causes replication stress signaling and a decrease in homologous recombination (HR). HBEC cells that overexpress NTHL1 or CATmut acquire the ability to grow in soft agar and exhibit loss of contact inhibition, suggesting that a mechanism independent of NTHL1 catalytic activity contributes to acquisition of cancer-related cellular phenotypes. We provide evidence that NTHL1 interacts with the multifunctional DNA repair protein XPG suggesting that interference with HR is a possible mechanism that contributes to acquisition of early cellular hallmarks of cancer.

Interleukin-22 (IL-22) Regulates Apoptosis of Paclitaxel-Resistant Non-Small Cell Lung Cancer Cells Through C-Jun N-Terminal Kinase Signaling Pathway

BACKGROUND Reducing drug resistance in tumor cells has become an important issue for cancer treatment. The purpose of this study was to investigate whether IL-22 was involved in lung cancer cell resistance to paclitaxel (PTX), and to explore the underlying molecular mechanism. MATERIAL AND METHODS Non-small cell lung cancer (NSCLC) cell line A549 and the drug resistant cell line A549/PTX were used in the present study. The inhibitory rate of PTX on A549 and A549/PTX cell proliferation was determined by MTT assay and the half-maximal inhibitory concentration (IC50) value was calculated. The expression level of IL-22 was detected using Western blot and qRT-PCR. To elucidate the mechanism by which IL-22 is involved in PTX resistance, a stable IL-22-silenced A549/PTX cell line was generated by using IL-22-siRNA. Cell apoptosis was analyzed by flow cytometry, and the c-Jun N-terminal kinase (JNK) signal pathway was determined using Western blot analysis. RESULTS We found that IL-22 expression level was markedly higher in A549/PTX cells than in A549 cells, and IL-22 gene knockdown significantly enhanced the cell proliferation inhibition rate of PTX to A549/PTX cells and decreased the IC50 value of PTX to A549/PTX cells, indicating IL-22 was involved in cell PTX resistance. Our findings also suggest that IL-22 knockdown notably increased PTX induced apoptosis in A549/PTX cells. Moreover, the results showed that p-JNK and Caspase 3 expression were significantly increased in IL-22 knockdown A549/PTX cells, while Bcl-2 expression was significantly decreased. CONCLUSIONS IL-22 is involved in A549 cell resistance to PTX through regulating cell apoptosis via the JNK signaling pathway.

Activation of AhR with nuclear IKKα regulates cancer stem-like properties in the occurrence of radioresistance

Most cancer patients receive radiotherapy in the course of their disease and the occurrence of radioresistance is associated with poor prognosis. The molecular pathways that drive enhanced tumorigenic potential during the development of radioresistance are poorly understood. Here, we demonstrate that aryl hydrocarbon receptor (AhR) plays a vital role in the maintenance of cancer stem-like properties. AhR promotes the cancer stem-like phenotype and drives metastasis by directly targeting the promoters of 'stemness' genes, such as the ATP-binding cassette sub-family G member 2 (ABCG2) gene. Moreover, the radioresistant sublines display high levels of oncometabolites including α-ketoglutarate, and treatment of cancer cells with α-ketoglutarate enhances their stem-like properties in an AhR activation-dependent manner. IKKα directly activates stemness-related genes through an interaction with AhR as a bone fide chromatin modifier. Thus, AhR is functionally linked with cancer stem-like properties, and it drives tumorigenesis in the occurrence of radioresistance.

Effect of Octreotide on Neuroenolase Levels in Patients with Small Cell Lung Cancer

Aims and Background

The somatostatin analog octreotide has an antiproliferative effect on small cell lung cancer lines in vitro and in experimental xenograft transplantation systems in vivo. Thus it is worth investigating octreotide activity in the clinical setting.

Methods

We studied the effect of octreotide (200 μg three times a day subcutaneously for seven days) on serum levels of the tumor marker neuroenolase in 13 patients with small cell lung cancer.

Results

A decrease in neuroenolase levels was observed at day 7 during octreotide treatment, with a mean ± SD of 32.6 ± 42.0 ng/ml compared to basal values of 44.4 ± 57.7 ng/ml and to washout values of 50.3 ± 65.7 ng/ml ( P < 0.03).

Conclusions

Our results indicate that octreotide is effective in reducing neuroenolase levels in small cell lung cancer patients. These data suggest a possible role for octreotide in the treatment of this kind of tumor.

Feiji Recipe inhibits the growth of lung cancer by modulating T-cell immunity through indoleamine-2,3-dioxygenase pathway in an orthotopic implantation model

OBJECTIVE

Escape from the body's immune response is a basic characteristic of lung cancer, and indoleamine-2,3-dioxygenase (IDO) plays a key role in mediating immune escape of non-small-cell lung cancer, which leads to recurrence and metastasis. Feiji Recipe, a compound Chinese herbal medicine, has the effect of stabilizing lesions and prolonging survival in patients with lung cancer. The purpose of this study was to investigate the mechanisms underlying the anticancer properties of Feiji Recipe.

METHODS

An orthotopic transplant model of mouse Lewis lung cancer, with stable expression of IDO gene, was established in C57BL/6 mice. Optical imaging was used to observe the effects of Feiji Recipe in the treatment of lung cancer in vivo. The effects of Feiji Recipe on the proliferation of mouse Lewis lung cancer cell line 2LL, 2LL-enhanced green fluorescent protein (2LL-EGFP) and 2LL-EGFP-IDO were investigated, and the apoptosis of T-cells was examined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide using flow cytometry. Chemical composition of Feiji Recipe was validated by high-performance liquid chromatography.

RESULTS

Compared to the control group, the survival of animals treated with Feiji Recipe was significantly prolonged (P = 0.0074), and the IDO protein level decreased (P = 0.0072); moreover, the percentages of CD4⁺CD25⁺ T-cells and Foxp3⁺ T-cells were significantly decreased (P < 0.05). The molecular mechanism of Feiji Recipe against lung cancer may relate to the regulation of immune cells, such as T-cells and regulatory T-cells.

CONCLUSION

The molecular mechanism of Feiji Recipe in treatment of lung cancer is to restore the function of T-cells in the cancer microenvironment through interfering with the IDO pathway.

High Mobility Group Box Protein 1 Serves as a Potential Prognostic Marker of Lung Cancer and Promotes Its Invasion and Metastasis by Matrix Metalloproteinase-2 in a Nuclear Factor-κB-Dependent Manner

Several studies have reported a significant role of high mobility group box protein 1 (HMGB1) in lung cancer. Nevertheless, there is a lack of knowledge regarding the expression of HMGB1 and its correlation with the clinicopathological features of lung cancer. In addition, the potential molecular mechanisms underlying the role of HMGB1 in lung cancer are still unknown. We therefore investigated the clinicopathological and prognostic significance as well as the potential role of HMGB1 in the development and progression of lung cancer. HMGB1 expression in the tumor tissues of the cohort correlated with clinicopathological features. Moreover, lung cell migration and invasion were significantly increased after treatment with HMGB1. The matrix metalloproteinase-2 (MMP-2) expression and activity were upregulated after treatment with HMGB1, while the upregulated expression of MMP-2 stimulated by HMGB1 in lung cancer cells was significantly reduced with the blockage of si-p65. These results indicated that HMGB1 expression was significantly associated with lung cancer progression. We also showed that HMGB1 promoted lung cancer invasion and metastasis by upregulating the expression and activity of MMP-2 in an NF-κB-dependent manner. Taken together, these data suggested that HMGB1 may be a potential prognosis and therapeutic marker for lung cancer.

Glucose-6-Phosphate Dehydrogenase Deficiency and Lung Cancer: A Hospital Based Case-Control Study

A hospital based case-control study was conducted to test the hypothesis of a lower lung cancer risk in G6PD-deficient subjects. Cases were 156 male patients with lung cancer, admitted to « Binaghi » Hospital, Local Health Unit (USL) 20, Cagliari (Italy), between January 1984 and November 1986. Controls were 235 male patients, admitted to the same hospital In the same time period, for diseases other than cancer (all types) and hemolytic anemia. No decrease of the lung cancer risk was found in G6PD-deficient subjects. This result, in line with recent reports in the literature, suggests that the genetic condition of G6PD deficiency does not provide significant protection against the development of lung cancer in humans.

Neuron-Specific Enolase

The clinical value of neuron-specific enolase as a marker in small cell lung cancer, neuroblastoma, melanoma and seminoma has been reviewed The role of serum and cerebrospinal NSE in benign and malignant disease of the central nervous sytem is discussed.

Tumor Markers and Lung Cancer: Correlation between Serum and Bronchial Secretion Levels of Cea, Tpa, Canag Ca-50, Nse and Ferritin

The levels of carcinoembryonic antigeny (CEA), tissue polypeptide antigeny (TPA), CanAg 50, neuron specific enolase (NSE) and ferritin were determined in bronchial secretion and serum of patients with neoplastic and non-neoplastic lung diseases. Simultaneous determination of two or three markers in the serum and in bronchoalveolar lavage (BAL) may be clinically useful for the diagnosis of lung cancer and even for the type of tumor. The positivity of CEA determined simultaneously in serum and in BAL of patients with lung cancer is higher than 80% whereas in patients with benign lung disease it is lower than 40%. The simultaneous assay of TP A in serum and in BAL showed 100% positivity in patients with oat-cell carcinoma, the frequencies of positivity were similar in patients with non-oat-cell carcinoma. For NSE and CanAg CA-50 patients with oat-cell carinoma showed 100% positivity. Simultaneous assay of ferritin in serum and in BAL gave 85% positivity in patients with oat-cell carcinoma and only 23% in patients with non-oat-cell carcinoma. We conclude that the simultaneous determination of CEA and CanAg CA-50 or NSE in serum and in BAL is a useful aid in the diagnosis of lung malignancy.

Methodologic Problems Encountered in the Assay of Proteinases in Lewis Lung Carcinoma, a Mouse Metastasizing Tumor

The proteolytic activity in homogenates and extracts of subcellular fractions prepared from subcutaneous Lewis lung carcinoma was determined using proteins and synthetic peptides as substrates. The presence of cathepsin D, plasminogen activator, cathepsin B-, cathepsin G-and elastase-like enzymes was observed. No difference was revealed between the proteolytic activity in homogenates of Lewis lung carcinoma, at the growth stage examined, and in homogenates of normal lung. High specific activities were found in the lysosomal extract, whereas decreasing activities were found in the nuclear extract, the homogenate and the post-lysosomal mitochondrial supernatant; no active or trypsin-activatable collagenase activity was detected. The presence in the tumor tissue of these enzymatic activities is in agreement with their proposed role in the process of metastasis. The lack of differences between homogenates of tumor and normal lung tissue suggests that the use of whole cells is required to selectively study tumor proteinases specifically involved in tumor malignancy.

Phosphohexose Isomerase and Carcinoembryonic Antigen in the Sera of Patients with Primary Lung Cancer

Phosphohexose isomerase (PHI) and carcinoembryonic antigen (CEA) were measured at the time of diagnosis in 300 patients with lung cancer. Serum levels were high in 75.7% and 53.0% of patients respectively. PHI levels were higher in large cell and small cell carcinomas (p < 0.001). CEA levels were higher in adenocarcinomas (p < 0.001). Metastatic carcinomas showed higher levels on PHI and CEA than localized cases. Survival was significantly longer in patients with normal PHI (p < 0.001) and normal CEA (p < 0.005) than in cases with elevated markers. The prognostic significance of PHI persisted in the different pathological types and stages, whereas CEA only had prognostic impact in non-small cell cases. Serial PHI determinations were useful for follow-up in 82.4% of cases with initial abnormal values and in 55.4% of cases with a normal value. Serial CEA was useful in 41% of cases with initially high value but in less than 15% of those with baseline normal. We conclude that PHI has prognostic significance independently of pathology and stage, whereas CEA was a prognostic indicator only in non-small cell cases; serial PHI determinations were useful more often than CEA for follow-up.

Single Nucleotide Polymorphisms in HMGB1 Correlate with Lung Cancer Risk in the Northeast Chinese Han Population

Lung cancer is the principal cause of cancer-associated deaths. HMGB1 has been reported to be associated with tumorigenesis. This study aimed to investigate the relationship between rs1412125 and rs1360485 polymorphisms in HMGB1 and the risk and survival of lung cancer. 850 cases and 733 controls were included. Logistic regression analysis and survival analysis were performed to investigate the association between SNPs and the risk and survival of lung cancer. Crossover analysis was used to analyze the interaction between SNPs and tobacco exposure. Results indicated that rs1412125 polymorphism was associated with lung cancer risk, especially with the risk of lung adenocarcinoma and small cell lung cancer. Carriers with CT and CC genotypes had a decreased risk of lung cancer (CT + CC vs.TT: adjusted OR = 0.736, p = 0.004). Similar results were obtained in the stratification analysis for non-smokers and female population. For rs1360485 polymorphism, AG and GG genotypes could decrease the risk of lung adenocarcinoma and female lung cancer by 0.771-fold and 0.789-fold. However, no significant interaction between polymorphisms and tobacco exposure or association between SNPs and the survival of lung cancer was observed. This study indicated polymorphisms in HMGB1 may be a novel biomarker for female lung adenocarcinoma risk.

CK1α suppresses lung tumour growth by stabilizing PTEN and inducing autophagy

The contribution of autophagy to cancer development remains controversial, largely owing to the fact that autophagy can be tumour suppressive or oncogenic in different biological contexts. Here, we show that in non-small-cell lung cancer (NSCLC), casein kinase 1 alpha 1 (CK1α) suppresses tumour growth by functioning as an autophagy inducer to activate an autophagy-regulating, tumour-suppressive PTEN/AKT/FOXO3a/Atg7 axis. Specifically, CK1α bound the C-terminal tail of PTEN and enhanced both PTEN stability and activity by competitively antagonizing NEDD4-1-induced PTEN polyubiquitination and abrogating PTEN phosphorylation, thereby inhibiting AKT activity and activating FOXO3a-induced transcription of Atg7. Notably, blocking CK1α-induced Atg7-dependent autophagy cooperates with oncogenic HRasV12 to initiate tumorigenesis of lung epithelial cells. An association of a CK1α-modulated autophagic program with the anti-neoplastic activities of the CK1α/PTEN/FOXO3a/Atg7 axis was demonstrated in xenografted tumour models and human NSCLC specimens. This provides insights into the biological and potentially clinical significance of autophagy in NSCLC.

Pepsinogen C Expression in Tumors of Extragastric Origin

We have examined by immunohistochemistry the ability of human carcinomas of various origin to produce pepsinogen C, an aspartyl proteinase mainly involved in the digestion of proteins in the stomach and recently found to be associated with breast carcinomas. Of the 268 tumors analyzed 80 (29.8%) showed positive staining for pepsinogen C. These positive tumors included 12 gastric (38.7% of the 31 examined cases), nine pancreatic (42.8%), two renal (20%), 12 prostatic (40%), three bladder (27.3%), 14 endometrial (29.7%) and 18 ovarian (40%) carcinomas. We also detected 10 melanomas (50%) that were positive for pepsinogen C. By contrast, immunohistochemical staining for the proteinase was not detected in colorectal, cervical, lung and basal cell skin carcinomas. These results demonstrate that pepsinogen C, a proteolytic enzyme of highly restricted expression in human tissues, can also be expressed by a wide variety of human carcinomas. In addition, and similar to pepsinogen C expression in breast carcinomas, the production of this enzyme by different human tumors might be related to putative hormonal alterations associated with the development and progression of these tumors.

Efficacy of Pemetrexed-based Chemotherapy in Comparison to Non-Pemetrexed-based Chemotherapy in Advanced, ALK+ Non-Small Cell Lung Cancer

PURPOSE

Previous retrospective studies suggest that anaplastic lymphoma kinase (ALK) mutation-positive (ALK+) non-small cell lung cancer (NSCLC) patients are sensitive to pemetrexed. To determine its efficacy, we retrospectively evaluated clinical outcomes of pemetrexed-based chemotherapy in patients with ALK+ NSCLC.

MATERIALS AND METHODS

We identified 126 patients with advanced, ALK+ NSCLC who received first-line cytotoxic chemotherapy. We compared response, progression-free survival (PFS), and overall survival (OS) rates according to chemotherapy regimens. Furthermore, we evaluated intracranial time to tumor progression (TTP) and proportion of ALK+ cells as prognostic factors.

RESULTS

Forty-eight patients received pemetrexed-based chemotherapy, while 78 received other regimens as first-line treatment. The pemetrexed-based chemotherapy group showed superior overall response (44.7% vs. 14.3%, p<0.001) and disease control (85.1% vs. 62.3%, p=0.008) rates. The pemetrexed-based chemotherapy group also exhibited longer PFS (6.6 months vs. 3.8 months, p<0.001); OS rates were not significantly different. The lack of exposure to second-generation ALK inhibitors and intracranial metastasis on initial diagnosis were independent negative prognostic factors of OS. Intracranial TTP was similar between the treatment groups (32.7 months vs. 35.7 months, p=0.733). Patients who harbored a greater number of ALK+ tumor cells (≥70%) showed prolonged OS on univariate analysis (not reached vs. 44.8 months, p=0.041), but not on multivariate analysis (hazard ratio: 0.19, 95% confidence interval: 0.03-1.42; p=0.106).

CONCLUSION

Pemetrexed-based regimens may prolong PFS in patients with ALK+ NSCLC as a first-line treatment, but are not associated with prolonged OS. Exposure to second-generation ALK inhibitors may improve OS rates in patients with ALK+ NSCLC.

Apoptosis Signal-Regulating Kinase 1 (ASK1) Activation is Involved in Silver Nanoparticles Induced Apoptosis of A549 Lung Cancer Cell Line

Silver nanoparticles (AgNPs) are one of the most important nanomaterials in the field of medicine. Our study investigated whether AgNPs induce apoptosis of human adenocarcinoma A549 cells and their possible involvement in Apoptosis Signal-Regulating Kinase 1 (ASK1). The prepared AgNPs had high stability and excellent monodispersity. They also possessed inhibitory effect on A549 cells proliferation in a concentration-dependent manner by Cell Counting Kit-8 (CCK8) assay and Hoechst 33342 Fluorescence. The AgNPs significantly induced production of reactive oxygen species (ROS) in A549 cells. We also observed an increased cytoplasmic staining of p-ASK1 in cells by immunocytochemical analysis, compared with non-treated cells. In addition, we found sequential activation of ASK1, c-Jun N terminal kinase (JNK), p38 Mitogen Activated Protein Kinase (p38) and caspase3 by Western blot after treatment with AgNPs. The AgNPs may thus inhibit growth of lung cancer cells and induce apoptosis. The anti-cancer mechanism for the AgNPs may be involved in activating the ASK1-JNK/p38-Caspase-3 pathway.

The Significance of MMP-1 in EGFR-TKI-Resistant Lung Adenocarcinoma: Potential for Therapeutic Targeting

Epidermal growth factor receptor–tyrosine kinase inhibitor (EGFR-TKI) resistance is one of the most important problems in lung cancer therapy. Lung adenocarcinoma with EGFR-TKI resistance was reported to have higher abilities of invasion and migration than cancers sensitive to EGFR-TKI, but the function of matrix metalloproteinases (MMPs) has not been explored in EGFR-TKI–resistant lung adenocarcinoma. This study aims to clarify the significance of MMP-1 in EGFR-TKI–resistant lung adenocarcinoma. From the results of in vitro studies of migration and invasion assays using EGFR-TKI–sensitive and –resistant cell lines and phosphorylation antibody arrays using EGF and rapamycin, we first demonstrate that overexpression of MMP-1, which might follow activation of a mammalian target of rapamycin (mTOR) pathway, plays an important role in the migration and invasion abilities of EGFR-TKI–resistant lung adenocarcinoma. Additionally, immunohistochemical studies using 89 cases of lung adenocarcinoma demonstrate that high expression of MMP-1 is significantly correlated with poor prognosis and factors such as smoking history and the subtype of invasive mucinous adenocarcinoma. These are consistent with the results of this in vitro study. To conclude, this study provides insights into the development of a possible alternative therapy manipulating MMP-1 and the mTOR signaling pathway in EGFR-TKI–resistant lung adenocarcinoma.

Asparagine bioavailability governs metastasis in a model of breast cancer

Using a functional model of breast cancer heterogeneity, we previously showed that clonal sub-populations proficient at generating circulating tumour cells were not all equally capable of forming metastases at secondary sites. A combination of differential expression and focused in vitro and in vivo RNA interference screens revealed candidate drivers of metastasis that discriminated metastatic clones. Among these, asparagine synthetase expression in a patient's primary tumour was most strongly correlated with later metastatic relapse. Here we show that asparagine bioavailability strongly influences metastatic potential. Limiting asparagine by knockdown of asparagine synthetase, treatment with l-asparaginase, or dietary asparagine restriction reduces metastasis without affecting growth of the primary tumour, whereas increased dietary asparagine or enforced asparagine synthetase expression promotes metastatic progression. Altering asparagine availability in vitro strongly influences invasive potential, which is correlated with an effect on proteins that promote the epithelial-to-mesenchymal transition. This provides at least one potential mechanism for how the bioavailability of a single amino acid could regulate metastatic progression.

Losmapimod Overcomes Gefitinib Resistance in Non-small Cell Lung Cancer by Preventing Tetraploidization

The epidermal growth factor receptor (EGFR) is known to play a critical role in non-small cell lung cancer (NSCLC). Constitutively active EGFR mutations, including in-frame deletion in exon 19 and L858R point mutation in exon 21, contribute about 90% of all EGFR-activating mutations in NSCLC. Although oral EGFR-tyrosine kinase inhibitors (TKIs), gefitinib and erlotinib, show dramatic clinical efficacy with significantly prolonged progression-free survival in patients harboring these EGFR-activating mutations, most of these patients will eventually develop acquired resistance. Researchers have recently named genomic instability as one of the hallmarks of cancer. Genomic instability usually involves a transient phase of polyploidization, in particular tetraploidization. Tetraploid cells can undergo asymmetric cell division or chromosome loss, leading to tumor heterogeneity and multidrug resistance. Therefore, identification of signaling pathways involved in tetraploidization is crucial in overcoming drug resistance. In our present study, we found that gefitinib could activate YAP-MKK3/6-p38 MAPK-STAT3 signaling and induce tetraploidization in gefitinib-resistance cells. Using p38 MAPK inhibitors, SB203580 and losmapimod, we could eliminate gefitinib-induced tetraploidization and overcome gefitinib-resistance. In addition, shRNA approach to knockdown p38α MAPK could prevent tetraploidy formation and showed significant inhibition of cancer cell growth. Finally, in an in vivo study, losmapimod could successfully overcome gefitinib resistance using an in-house established patient-derived xenograft (PDX) mouse model. Overall, these findings suggest that losmapimod could be a potential clinical agent to overcome gefitinib resistance in NSCLC.

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Gefitinib induces tetraploidy formation in gefitinib-resistant NSCLC cells

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YAP-MKK3/6-p38 MAPK signaling is essential for tetraploidization

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Losmapimod, a p38 MAPK inhibitor, overcomes gefitinib-resistance both in vitro and PDX xenograft mode

Gefitinib is a targeted drug therapy in non-small cell lung cancer (NSCLC) which shows dramatic clinical efficacy. However, most of these patients eventually develop drug resistance. Although researchers have identified different mechanisms contributing to the drug resistance, developing a single therapy to overcome the drug resistance remains difficult. In this study, we find that tetraploidization of cancer cells through YAP-MKK3/6-p38 MAPK signaling could be one of the common mechanisms in developing the drug resistance. By using losmapimod, we could eliminate tetraploidization and overcome gefitinib resistance in an animal model suggesting that losmapimod could be a potential clinical agent to overcome gefitinib resistance in NSCLC.

Cytosolic Levels of Neuron-Specific Enolase in Squamous Cell Carcinomas of the Lung

To study the behavior and possible correlations of neuron-specific enolase (NSE) with other clinicobiological parameters, we measured the cytosolic levels of this marker by means of an immunoradiometric assay (IRMA) in 95 squamous cell lung carcinoma samples. We also analyzed the levels of pS2, tissue-type plasminogen activator (t-PA), hyaluronic acid (HA), free beta subunit of human chorionic gonadotropin (β-HCG), CYFRA 21.1 and CA 125 in cytosol. On the cell surface we analyzed the concentrations of epidermal growth factor receptor (EGFR), HA, erbB-2 oncoprotein, CD44s, CD44v5 and CD44v6. Other parameters considered were clinical stage, lymph node involvement, histological grade (HG), ploidy and the cellular S-phase fraction measured by flow cytometry on nuclei obtained from fresh tissues.

In the 95 squamous cell carcinomas the cytosolic levels of NSE varied from 4.5 to 2235 ng/mg protein (median: 267) and were significantly higher (p<0.001) than those observed in 38 samples of normal pulmonary tissue obtained from the same patients (range: 56–657; median: 141.5). When classifying tumors according to the different parameters analyzed, we observed that the levels of NSE were higher in aneuploid than in diploid cases (p=0.046) and in those that were HG3 than in those that were HG2 (p<0.001). Tumors with high NSE levels (>422 ng/mg protein; 75th percentile) were more likely to have high S-phase values (p=0.012) and were more frequently aneuploid (p=0.038) and HG3 (p<0.001) than those with low levels of NSE (<180 ng/mg protein; 25th percentile).

These results lead us to the following conclusions: 1) the cytosolic concentrations of NSE are significantly higher in squamous cell carcinomas than in healthy pulmonary tissue, and 2) the cytosolic concentrations of NSE are not correlated with clinical stage or nodal involvement. However, in our study higher levels of the enzyme were statistically correlated with aneuploidy, histological grade 3 and S-phase. This may explain its association with poorer outcome and progression, but also the more favorable response of tumors with elevated NSE to chemotherapy, as suggested by other groups.

V600E BRAF versus Non-V600E BRAF Mutated Lung Adenocarcinomas: Cytomorphology, Histology, Coexistence of Other Driver Mutations and Patient Characteristics

OBJECTIVES

We analyzed the morphologic features and clinical characteristics of lung adenocarcinomas (ACAs) harboring mutated BRAF.

STUDY DESIGN

A review of the histology/cytology of BRAF-mutated lung ACAs was performed at the Johns Hopkins Hospital from January 1, 2013, to January 1, 2015. Patient demographics, clinical history, and ACA morphology were assessed.

RESULTS

Thirty-six cases were identified with a median age of 66 years (range 44-87), 58% (21/36) were female, and 94% (34/36) were current or former smokers. In total, 28% (10/36) had a BRAF-V600E mutation. Concurrent mutations were identified in KRAS in 4 cases (11%), PIK3CA in 2 cases (6%), and AKT1 in 2 cases (6%). No cases tested for ALK rearrangement were positive. The tumor grading varied from well to poorly differentiated, and the architecture assumed various patterns, including papillary, micropapillary, solid/cribriform, lepidic, and acinar. Of the cases with immunostains, 90% (18/20) were TTF-1 positive, 88% (14/16) were napsin-A positive, and 100% (8/8) were P63 negative.

CONCLUSION

Mutated-BRAF lung ACA arose on average in the seventh decade of life in patients who were current or former smokers and was infrequently found in combination with other common lung ACA driver mutations. The actionable V600E mutation was present in <30% of cases, more commonly in females. The histologic grade and architecture of these tumors varied significantly.

Screening for ALK abnormalities in central nervous system metastases of non-small-cell lung cancer

Anaplastic lymphoma kinase (ALK) gene rearrangement was reported in 3%-7% of primary non-small-cell lung cancer (NSCLC) and its presence is commonly associated with adenocarcinoma (AD) type and non-smoking history. ALK tyrosine kinase inhibitors (TKIs) such as crizotinib, alectinib and ceritinib showed efficiency in patients with primary NSCLC harboring ALK gene rearrangement. Moreover, response to ALK TKIs was observed in central nervous system (CNS) metastatic lesions of NSCLC. However, there are no reports concerning the frequency of ALK rearrangement in CNS metastases. We assessed the frequency of ALK abnormalities in 145 formalin fixed paraffin embedded (FFPE) tissue samples from CNS metastases of NSCLC using immunohistochemical (IHC) automated staining (BenchMark GX, Ventana, USA) and fluorescence in situ hybridization (FISH) technique (Abbot Molecular, USA). The studied group was heterogeneous in terms of histopathology and smoking status. ALK abnormalities were detected in 4.8% (7/145) of CNS metastases. ALK abnormalities were observed in six AD (7.5%; 6/80) and in single patients with adenosuqamous lung carcinoma. Analysis of clinical and demographic factors indicated that expression of abnormal ALK was significantly more frequently observed (P = 0.0002; χ²  = 16.783) in former-smokers. Comparison of IHC and FISH results showed some discrepancies, which were caused by unspecific staining of macrophages and glial/nerve cells, which constitute the background of CNS tissues. Their results indicate high frequency of ALK gene rearrangement in CNS metastatic sites of NSCLC that are in line with prior studies concerning evaluation of the presence of ALK abnormalities in such patients. However, they showed that assessment of ALK by IHC and FISH methods in CNS tissues require additional standardizations.

Dabrafenib in combination with trametinib in the treatment of patients with BRAF V600-positive advanced or metastatic non-small cell lung cancer: clinical evidence and experience

Mutations in the BRAF oncogene are found in 2-4% of all non-small cell lung cancer (NSCLC) patients. The most common activating mutation present within the BRAF oncogene is associated with valine substitution for glutamate at position 600 (V600E) within the BRAF kinase. BRAF-targeted therapies are effective in patients with melanoma and NSCLC harboring BRAF V600E mutation. In both melanoma and NSCLC, dual inhibition of both BRAF and the downstream mitogen-activated protein kinase (MEK) improves response rates compared with BRAF inhibition alone. BRAF-MEK combination therapy (dabrafenib plus trametinib) demonstrated tolerability and efficacy in a recent phase II clinical trial and was approved by the European Medicines Agency and United States Food and Drug Administration for patients with stage IV NSCLC harboring BRAF V600E mutation. Here, in this review, we outline the preclinical and clinical data for BRAF and MEK inhibitor combination treatment for NSCLC patients with BRAF V600E mutation.

Xanthatin triggers Chk1-mediated DNA damage response and destabilizes Cdc25C via lysosomal degradation in lung cancer cells

Previous studies had shown that xanthatin, a natural xanthanolide sesquiterpene lactone, could induce mitotic arrest and apoptosis in non-small cell lung cancer (NSCLC) cells. Here, we examined whether the DNA damage response (DDR) could be a primary cytotoxic event underlying xanthatin-mediated anti-tumor activity. Using EdU incorporation assay in combination with novel imaging flow cytometry, our data indicated that xanthatin suppressed DNA replication, prevented cells from G2/M entry and increased the spot count of γH2AX nuclear foci. Given that checkpoint kinase 1 (Chk1) represents a core component in DDR-mediated cell cycle transition and the phosphorylation on Ser-345 is essential for kinase activation and function, we surprisingly found xanthatin distinctly modulated Ser-345 phosphorylation of Chk1 in A549 and H1299 cells. Further investigation on Cdc25C/CDK1/CyclinB1 signaling cascade in the absence or presence of pharmacological DDR inhibitors showed that xanthatin directly destabilized the protein levels of Cdc25C, and recovery of p53 expression in p53-deficient H1299 cells further intensified xanthatin-mediated inhibition of Cdc25C, suggesting p53-dependent regulation of Cdc25C in a DDR machinery. Moreover, exogenous expression of Cdc25C was also substantially repressed by xanthatin and partially impaired xanthatin-induced G2 arrest. In addition, xanthatin could induce accumulation of ubiquitinated Cdc25C without undergoing further proteasomal degradation. However, an alternative lysosomal proteolysis of Cdc25C was observed. Interestingly, lysosome-like vesicles were produced upon xanthatin treatment, accompanied by rapid accumulation of lysosomal associated membrane protein LAPM-1. Furthermore, vacuolar proton (V)-ATPases inhibitor bafilomycin A1 and lysosomal proteases inhibitor leupeptin could remarkably overturn the levels of Cdc25C in xanthatin-treated H1299 cells. Altogether, these data provide insight into how xanthatin can be effectively targeted DDR molecules towards certain tumors.

Knockdown of REV3 synergizes with ATR inhibition to promote apoptosis induced by cisplatin in lung cancer cells

It has been demonstrated that REV3, the catalytic subunit of the translesion synthesis (TLS) polymerase ζ, play an important role in DNA damage response (DDR) induced by cisplatin, and Ataxia-telangietasia mutated and Rad-3-related (ATR) knase is a central player in activating cell cycle checkpoint, stabilizing replication forks, regulating DDR, and promoting repair of DNA damage caused by cisplatin. Cancer cells deficient in either one of REV3 and ATR are more sensitive to cisplatin. However, whether co-inhibition of REV3 and ATR can further increase sensitivity of non-small cell lung cancer (NSCLC) cells to cisplatin is not clear. In this study, we show that REV3 knockdown combined with ATR inhibition further enhance cytotoxicity of cisplatin in NSCLC cells, including cisplatin-sensitive and -resistant cell lines, compared to individual knockdown of REV3 or ATR, which are accompanied by markedly caspase-dependent apoptosis response, pronounced DNA damage accumulation and severe impediment of interstrand crosslink (ICL), and double strand break (DSB) repair. Our results suggest that REV3 knockdown synergize strongly with ATR inhibition to significantly increase sensitivity of cisplatin in NSCLC cells by inhibiting ICL and DSB repair. Thus simultaneously targeting REV3 and ATR may represent one approach to overcome cisplatin resistance and improve chemotherapeutic efficacy in NSCLC treatment.

Breast Cancer-Derived Lung Metastases Show Increased Pyruvate Carboxylase-Dependent Anaplerosis

Cellular proliferation depends on refilling the tricarboxylic acid (TCA) cycle to support biomass production (anaplerosis). The two major anaplerotic pathways in cells are pyruvate conversion to oxaloacetate via pyruvate carboxylase (PC) and glutamine conversion to α-ketoglutarate. Cancers often show an organ-specific reliance on either pathway. However, it remains unknown whether they adapt their mode of anaplerosis when metastasizing to a distant organ. We measured PC-dependent anaplerosis in breast-cancer-derived lung metastases compared to their primary cancers using in vivo ¹³C tracer analysis. We discovered that lung metastases have higher PC-dependent anaplerosis compared to primary breast cancers. Based on in vitro analysis and a mathematical model for the determination of compartment-specific metabolite concentrations, we found that mitochondrial pyruvate concentrations can promote PC-dependent anaplerosis via enzyme kinetics. In conclusion, we show that breast cancer cells proliferating as lung metastases activate PC-dependent anaplerosis in response to the lung microenvironment.

Crizotinib resistance overcome by ceritinib in an ALK-positive non-small cell lung cancer patient with brain metastases: A case report

RATIONALE

The treatment of non-small cell lung cancer (NSCLC) has now changed dramatically in recent years and anaplastic lymphoma receptor tyrosine kinase (ALK) inhibitors are developing rapidly.

PATIENT CONCERNS

Here we reported a 57-year-old ALK-positive NSCLC man with brain metastases.

DIAGNOSES

A case of lung adenocarcinoma with brain metastases.

INTERVENTIONS

Crizotinib was administered orally at a dose of 250mg twice a day until the brain metastases were found. Treatment with orally administered ceritinib at a dose of 450mg/d was initiated after crizotinib treatment.

OUTCOMES

The patient is currently receiving maintenance ceritinib treatment, with no evidence of extracranial or intracranial tumor progression for 25 months.

LESSONS

Ceritinib may be a good choice for ALK-positive NSCLC patients with brain metastases who acquire resistance to crizotinib.

First-line icotinib versus cisplatin/pemetrexed plus pemetrexed maintenance therapy for patients with advanced EGFR mutation-positive lung adenocarcinoma (CONVINCE): a phase 3, open-label, randomized study

BACKGROUND

Icotinib has been previously shown to be non-inferior to gefitinib in non-selected advanced non-small-cell lung cancer patients when given as second- or further-line treatment. In this open-label, randomized, phase 3 CONVINCE trial, we assessed the efficacy and safety of first-line icotinib versus cisplatin/pemetrexed plus pemetrexed maintenance in lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) mutation.

PATIENTS AND METHODS

Eligible participants were adults with stage IIIB/IV lung adenocarcinoma and exon 19/21 EGFR mutations. Participants were randomly allocated (1 : 1) to receive oral icotinib or 3-week cycle of cisplatin plus pemetrexed for up to four cycles; non-progressive patients after four cycles were maintained with pemetrexed until disease progression or intolerable toxicity. The primary end point was progression-free survival (PFS) assessed by independent response evaluation committee. Other end points included overall survival (OS) and safety.

RESULTS

Between January 2013 and August 2014, 296 patients were randomized, and 285 patients were treated (148 to icotinib, 137 to chemotherapy). Independent response evaluation committee-assessed PFS was significantly longer in the icotinib group (11.2 versus 7.9 months; hazard ratio, 0.61, 95% confidence interval 0.43-0.87; P = 0.006). No significant difference for OS was observed between treatments in the overall population or in EGFR-mutated subgroups (exon 19 Del/21 L858R). The most common grade 3 or 4 adverse events (AEs) in the icotinib group were rash (14.8%) and diarrhea (7.4%), compared with nausea (45.9%), vomiting (29.2%), and neutropenia (10.9%) in the chemotherapy group. AEs (79.1% versus 94.2%; P < 0.001) and treatment-related AEs (54.1% versus 90.5%; P < 0.001) were significantly fewer in the icotinib group than in the chemotherapy group.

CONCLUSIONS

First-line icotinib significantly improves PFS of advanced lung adenocarcinoma patients with EGFR mutation with a tolerable and manageable safety profile. Icotinib should be considered as a first-line treatment for this patient population.

The RNA-editing enzyme ADAR promotes lung adenocarcinoma migration and invasion by stabilizing FAK

Large-scale, genome-wide studies report that RNA binding proteins are altered in cancers, but it is unclear how these proteins control tumor progression. We found that the RNA-editing protein ADAR (adenosine deaminase acting on double-stranded RNA) acted as a facilitator of lung adenocarcinoma (LUAD) progression through its ability to stabilize transcripts encoding focal adhesion kinase (FAK). In samples from 802 stage I LUAD patients, increased abundance of ADAR at both the mRNA and protein level correlated with tumor recurrence. Knocking down ADAR in LUAD cells suppressed their mesenchymal properties, migration, and invasion in culture. Analysis of gene expression patterns in LUAD cells identified ADAR-associated enrichment of a subset of genes involved in cell migration pathways; among these, FAK is the most notable gene whose expression was increased in the presence of ADAR. Molecular analyses revealed that ADAR posttranscriptionally increased FAK protein abundance by binding to the FAK transcript and editing a specific intronic site that resulted in the increased stabilization of FAK mRNA. Pharmacological inhibition of FAK blocked ADAR-induced invasiveness of LUAD cells, suggesting a potential therapeutic application for LUAD that has a high abundance of ADAR.

Pyruvate kinase M knockdown-induced signaling via AMP-activated protein kinase promotes mitochondrial biogenesis, autophagy, and cancer cell survival

Preferential expression of the low-activity (dimeric) M2 isoform of pyruvate kinase (PK) over its constitutively active splice variant M1 isoform is considered critical for aerobic glycolysis in cancer cells. However, our results reported here indicate co-expression of PKM1 and PKM2 and their possible physical interaction in cancer cells. We show that knockdown of either PKM1 or PKM2 differentially affects net PK activity, viability, and cellular ATP levels of the lung carcinoma cell lines H1299 and A549. The stable knockdown of PK isoforms in A549 cells significantly reduced the cellular ATP level, whereas in H1299 cells the level of ATP was unaltered. Interestingly, the PKM1/2 knockdown in H1299 cells activated AMP-activated protein kinase (AMPK) signaling and stimulated mitochondrial biogenesis and autophagy to maintain energy homeostasis. In contrast, knocking down either of the PKM isoforms in A549 cells lacking LKB1, a serine/threonine protein kinase upstream of AMPK, failed to activate AMPK and sustain energy homeostasis and resulted in apoptosis. Moreover, in a similar genetic background of silenced PKM1 or PKM2, the knocking down of AMPKα1/2 catalytic subunit in H1299 cells induced apoptosis. Our findings help explain why previous targeting of PKM2 in cancer cells to control tumor growth has not met with the expected success. We suggest that this lack of success is because of AMPK-mediated energy metabolism rewiring, protecting cancer cell viability. On the basis of our observations, we propose an alternative therapeutic strategy of silencing either of the PKM isoforms along with AMPK in tumors.

Decreased expression of cytochrome p450 1B1 in non-small cell lung cancer

Recent studies have associated oestrogen metabolism and cigarette smoking with their carcinogenic impact on the lungs. Compounds commonly found in tobacco smoke induce the activity of CYP1B1, the enzyme responsible for the synthesis of catecholic derivatives of oestrogens. During their redox transformations, these structures can release large amounts of reactive oxygen species or can form DNA adducts, which lead to the decomposition of genetic material. This process may illustrate the synergistic effect of oestrogenic activity and tobacco combustion on oestrogen-dependant lung cancer development. There is considerable evidence suggesting that the level of oestrogen in lung tumours is elevated. Therefore, by using reverse transcription, real-time PCR and Western Blot analysis, we evaluated the CYP1B1 status in tissues from 76 patients diagnosed with non-small cell lung cancer (NSCLC) to confirm whether potential overexpression of CYP1B1 may impact lung cancerogenesis induced by oestrogens. We found significantly lower levels of CYP1B1 transcripts (p=0.00001) and proteins (p=0.000085) in lung tumour material compared to corresponding, histopathologically unchanged tissues. We also analysed the association of CYP1B1 expression with gender, age and clinicopathological data of NSCLC patients. We observed lower amounts of CYP1B1 occurring in the middle stages of LC, regardless of gender, age or histological type of lung cancer.

Selective small-chemical inhibitors of protein arginine methyltransferase 5 with anti-lung cancer activity

Protein arginine methyltransferase 5 (PRMT5) plays critical roles in a wide variety of biological processes, including tumorigenesis. By screening a library of small chemical compounds, we identified eight compounds that selectively inhibit the PRMT5 enzymatic activity, with IC₅₀ values ranging from 0.1 to 6 μM. Molecular docking simulation and site-directed mutagenesis indicated that identified compounds target the substrate-binding site in PRMT5. Treatment of lung cancer cells with identified inhibitors led to inhibition of the symmetrical arginine methylation of SmD3 and histones and the cellular proliferation. Oral administration of the inhibitor demonstrated antitumor activity in a lung tumor xenograft model. Thus, identified PRMT5-specific small-molecule inhibitors would help elucidate the biological roles of PRMT5 and serve as lead compounds for future drug development.

Lactate dehydrogenase and creatine kinase as poor prognostic factors in lung cancer: A retrospective observational study

PURPOSE

Circulating molecules play important roles in lung cancer diagnosis. In addition, plasma lactate dehydrogenase (LDH) and creatine kinase (CK) have been shown to be closely related to tumor progression in breast cancer, prostate cancer, and colonel cancer. However, the relationships between LDH and CK levels with metastasis occurrence and the survival status of lung cancer patients remain unclear.

EXPERIMENTAL DESIGN

A total of 1142 lung cancer patients were enrolled in this study and were separated into negative or positive groups, according to the plasma levels of CK or LDH. Patients in both groups were assessed for clinical characteristics, metastasis occurrence, and survival status. The Cox regression model was then introduced to confirm whether CK and LDH could act as independent factors for predicting a poor prognosis.

RESULTS

The results indicated that CK had a close relationship with bone (p < 0.05) and lymph node (p < 0.05) metastases. In addition, LDH was strongly related with bone (p < 0.05), adrenal gland (p < 0.05), and lymph node (p < 0.05) metastases. CK and LDH were also correlated with the survival status of the lung cancer patients (all p < 0.001). According to specific histological classification analysis, it was found that CK was closely related to the survival status of adenocarcinoma (ADC) and squamous cell carcinoma (SCC) patients, while LDH was only correlated with that of ADC patients. Cox regression analysis confirmed that CK and LDH could act as independent factors for predicting a poor prognosis in ADC but not SCC patients.

CONCLUSIONS

For the first time, our study confirmed the role of CK in metastasis occurrence and the survival status of lung cancer patients. In addition, it also demonstrated that CK and LDH could be used as independent factors to predict a poor prognosis in ADC patients. The identification of CK and LDH will play important roles in lung cancer diagnosis and poor outcome prediction in the future.

Histone deacetylase HDAC1 expression correlates with the progression and prognosis of lung cancer: A meta-analysis

BACKGROUND

Histone deacetylase 1 (HDAC1) is an important epigenetic factor, and is thought to be associated with the progression and prognosis of some types of cancer. HDAC1 has been reported to be overexpressed in lung cancer, but the correlation between HDAC1 overexpression and the clinical features or prognosis of lung cancer is controversial. In this study, we investigated the potential association between HDAC1 and lung cancer.

MATERIALS AND METHODS

Embase, Web of Science, PubMed, and other sources were searched for relevant studies. Pooled odds ratios (ORs) or hazard ratios (HRs) with 95% confidence interval (CI) were calculated to evaluate the association of HDAC1 with lung cancer risk.

RESULTS

Eight eligible studies were included in the final meta-analysis. We found that HDAC1 mRNA or protein expression was closely associated with the differentiation grade of lung cancer (OR = 2.36, 95% CI = 1.14-4.87, P = .02). In addition, the protein expression level of HDAC1 in squamous cell carcinoma was higher than that in adenocarcinoma (OR = 1.81, 95% CI = 1.13-2.90, P = .01). Finally, HDAC1 mRNA or protein expression was negatively correlated with the overall survival rate of patients with lung cancer (HR = 2.40, 95% CI = 1.48-3.88, P = .0004).

CONCLUSION

In this meta-analysis, our results suggest that HDAC1 may serve as a good diagnostic and prognostic marker for lung cancer.

Secretory Stanniocalcin 1 promotes metastasis of hepatocellular carcinoma through activation of JNK signaling pathway

The hypoxic microenvironment is well-characterized in hepatocellular carcinoma (HCC). Delineation of hypoxia-responsive events is an integral part to understand the pathogenesis of HCC. We studied the functional role and clinical relevance of Stanniocalcin 1 (STC1), a hypoxia-induced molecular target, in HCC. In our clinical cohort, STC1 transcript was up-regulated in HCC tumor tissues. Moreover, STC1 protein was detected in the sera of HCC patients. A higher serum STC1 level was correlated with larger tumor size and poorer 5-year disease-free survival. Functionally, recombinant STC1 protein (rhSTC1) promoted cell migration and cell invasion in vitro; and the effect was abolished by co-treatment of anti-STC1 neutralizing antibody. By in vivo mouse model, silencing of STC1 in HCC cells downregulated secretory STC1 level and suppressed lung metastasis. Furthermore, we found that rhSTC1 activated the JNK pathway, as evidenced by altered expression of the key molecular targets pJNK and p-c-Jun. The functional effects conferred by rhSTC1 were abrogated by co-treatment of JNK inhibitor. In summary, secretory STC1 enhances metastatic potential of HCC via JNK signaling. It potentially serves as a prognostic serum biomarker and a therapeutic target for HCC.

LncRNA MEG3 downregulation mediated by DNMT3b contributes to nickel malignant transformation of human bronchial epithelial cells via modulating PHLPP1 transcription and HIF-1α translation

Long noncoding RNAs (lncRNAs) are emerging as key factors in various fundamental cellular biological processes, and many of them are likely to have functional roles in tumorigenesis. Maternally expressed gene 3 (MEG3) is an imprinted gene located at 14q32 that encodes a lncRNA, and the decreased MEG3 expression has been reported in multiple cancer tissues. However, nothing is known about the alteration and role of MEG3 in environmental carcinogen-induced lung tumorigenesis. Our present study, for the first time to the best of our knowledge, discovered that environmental carcinogen nickel exposure led to MEG3 downregulation, consequently initiating c-Jun-mediated PHLPP1 transcriptional inhibition and hypoxia-inducible factor-1α (HIF-1α) protein translation upregulation, in turn resulting in malignant transformation of human bronchial epithelial cells. Mechanistically, MEG3 downregulation was attributed to nickel-induced promoter hypermethylation via elevating DNMT3b expression, whereas PHLPP1 transcriptional inhibition was due to the decreasing interaction of MEG3 with its inhibitory transcription factor c-Jun. Moreover, HIF-1α protein translation was upregulated via activating the Akt/p70S6K/S6 axis resultant from PHLPP1 inhibition in nickel responses. Collectively, we uncover that nickel exposure results in DNMT3b induction and MEG3 promoter hypermethylation and expression inhibition, further reduces its binding to c-Jun and in turn increasing c-Jun inhibition of PHLPP1 transcription, leading to the Akt/p70S6K/S6 axis activation, and HIF-1α protein translation, as well as malignant transformation of human bronchial epithelial cells. Our studies provide a significant insight into understanding the alteration and role of MEG3 in nickel-induced lung tumorigenesis.

Alectinib versus crizotinib in patients with ALK-positive non-small-cell lung cancer (J-ALEX): an open-label, randomised phase 3 trial

BACKGROUND

Alectinib, a potent, highly selective, CNS-active inhibitor of anaplastic lymphoma kinase (ALK), showed promising efficacy and tolerability in the single-arm phase 1/2 AF-001JP trial in Japanese patients with ALK-positive non-small-cell lung cancer. Given those promising results, we did a phase 3 trial to directly compare the efficacy and safety of alectinib and crizotinib.

METHODS

J-ALEX was a randomised, open-label, phase 3 trial that recruited ALK inhibitor-naive Japanese patients with ALK-positive non-small-cell lung cancer, who were chemotherapy-naive or had received one previous chemotherapy regimen, from 41 study sites in Japan. Patients were randomly assigned (1:1) via an interactive web response system using a permuted-block method stratified by Eastern Cooperative Oncology Group performance status, treatment line, and disease stage to receive oral alectinib 300 mg twice daily or crizotinib 250 mg twice daily until progressive disease, unacceptable toxicity, death, or withdrawal. The primary endpoint was progression-free survival assessed by an independent review facility. The efficacy analysis was done in the intention-to-treat population, and safety analyses were done in all patients who received at least one dose of the study drug. The study is ongoing and patient recruitment is closed. This study is registered with the Japan Pharmaceutical Information Center (number JapicCTI-132316).

FINDINGS

Between Nov 18, 2013, and Aug 4, 2015, 207 patients were recruited and assigned to the alectinib (n=103) or crizotinib (n=104) groups. At data cutoff for the second interim analysis, 24 patients in the alectinib group had discontinued treatment compared with 61 in the crizotinib group, mostly due to lack of efficacy or adverse events. At the second interim analysis (data cutoff date Dec 3, 2015), an independent data monitoring committee determined that the primary endpoint of the study had been met (hazard ratio 0·34 [99·7% CI 0·17-0·71], stratified log-rank p<0·0001) and recommended an immediate release of the data. Median progression-free survival had not yet been reached with alectinib (95% CI 20·3-not estimated) and was 10·2 months (8·2-12·0) with crizotinib. Grade 3 or 4 adverse events occurred at a greater frequency with crizotinib (54 [52%] of 104) than alectinib (27 [26%] of 103). Dose interruptions due to adverse events were also more prevalent with crizotinib (77 [74%] of 104) than with alectinib (30 [29%] of 103), and more patients receiving crizotinib (21 [20%]) than alectinib (nine [9%]) discontinued the study drug because of an adverse event. No adverse events with a fatal outcome occurred in either treatment group.

INTERPRETATION

These results provide the first head-to-head comparison of alectinib and crizotinib and have the potential to change the standard of care for the first-line treatment of ALK-positive non-small-cell lung cancer. The dose of alectinib (300 mg twice daily) used in this study is lower than the approved dose in countries other than Japan; however, this limitation is being addressed in the ongoing ALEX study.

FUNDING

Chugai Pharmaceutical Co, Ltd.

Genetic Determinants of 1,3-Butadiene Metabolism and Detoxification in Three Populations of Smokers with Different Risks of Lung Cancer

Background: 1,3-Butadiene (BD) is an important carcinogen in tobacco smoke that undergoes metabolic activation to DNA-reactive epoxides. These species can be detoxified via glutathione conjugation and excreted in urine as the corresponding N-acetylcysteine conjugates. We hypothesize that single nucleotide polymorphisms (SNPs) in BD-metabolizing genes may change the balance of BD bioactivation and detoxification in White, Japanese American, and African American smokers, potentially contributing to ethnic differences in lung cancer risk.Methods: We measured the levels of BD metabolites, 1- and 2-(N-acetyl-L-cysteine-S-yl)-1-hydroxybut-3-ene (MHBMA) and N-acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA), in urine samples from a total of 1,072 White, Japanese American, and African American smokers and adjusted these values for body mass index, age, batch, and total nicotine equivalents. We also conducted a genome-wide association study to identify genetic determinants of BD metabolism.Results: We found that mean urinary MHBMA concentrations differed significantly by ethnicity (P = 4.0 × 10-25). African Americans excreted the highest levels of MHBMA followed by Whites and Japanese Americans. MHBMA levels were affected by GSTT1 gene copy number (P < 0.0001); conditional on GSTT1, no other polymorphisms showed a significant association. Urinary DHBMA levels also differed between ethnic groups (P = 3.3 × 10-4), but were not affected by GSTT1 copy number (P = 0.226).Conclusions:GSTT1 gene deletion has a strong effect on urinary MHBMA levels, and therefore BD metabolism, in smokers.Impact: Our results show that the order of MHBMA levels among ethnic groups is consistent with their respective lung cancer risk and can be partially explained by GSTT1 genotype. Cancer Epidemiol Biomarkers Prev; 26(7); 1034-42. ©2017 AACR.

Expression and significance of DDX43 in lung adenocarcinoma

This paper aims to determine the expression and clinical significance of DDX43 in lung adenocarcinoma. Expression of DDX43 gene and protein of lung adenocarcinoma tissue and para-carcinoma tissues was observed in 27 cases by RT-PCR and immunohistochemistry. These patients were diagnosed as lung adenocarcinoma in the Huaihe Hospital of Henan University from February 2015 to December 2015. The relative ratio of DDX43 mRNA expression in lung adenocarcinoma and para-carcinoma tissues was 0.87±0.62 versus 0.21±0.77 and the difference between the two groups was statistically significant (P<0.01). The expression of DDX43 in normal lung tissues and lung adenocarcinoma tissues was different. The positive rate of DDX43 expression in lung adenocarcinoma tissues was significantly higher than that in normal lung tissues, and the difference was statistically significant (P<0.05). The analysis of clinical pathological characteristics showed that the increase of protein expression was related to the stage and metastasis of lung adenocarcinoma. DDX43 is highly expressed in lung adenocarcinoma, and the expression level is related to the stage and metastasis of lung adenocarcinoma, suggesting that DDX43 is closely related to the occurrence and development of lung adenocarcinoma, and may be a molecular marker for early diagnosis of lung adenocarcinoma.