Pharmacogenomics of platinum-based chemotherapy in non-small cell lung cancer: focusing on DNA repair systems

Genetic variations in ABC transporter genes as a predictive biomarker for toxicity in North Indian lung cancer patients undergoing platinum-based doublet chemotherapy

ATP-binding cassette (ABC) transporters are expressed in various human tissues and play a vital role in the efflux of various chemotherapeutic drugs. The current study has assessed genetic variants of ABCB1, ABCC1, ABCC2, and ABCG2 genes in 407 lung cancer patients undergoing platinum-based doublet chemotherapy. The association of ABCB1 (C¹²³⁶ T, C³⁴³⁵ T, and G²⁶⁷⁷ T/A), ABCC1 (G³¹⁷³ A and G²¹⁶⁸ A),ABCC2 (G⁴⁵⁴⁴ A), and ABCG2 (C⁴²¹ A) polymorphisms with chemotherapy-induced adverse events were assessed, and statistical analysis was conducted. Our data showed that patients harboring heterozygous (GA) genotype for ABCC1 G³¹⁷³ A had an increased risk of developing leukopenia (odds ratio [OR] = 1.88, p = 0.04) and anemia (adjusted odds ratio [AOR] = 2.70, p = 0.03). For ABCC2 G⁴⁵⁴⁴ A polymorphism, patients harboring one copy of the mutant (GA) allele showed an increased risk of developing anemia (OR = 4.24, p = 0.03). After adjusting with various confounding factors, the heterozygous (GA) genotype showed a 5.63-fold increased risk of developing anemia (AOR = 5.63, p = 0.03). The ABCB1 G²⁶⁷⁷ A (OR = 0.37, p = 0.008) and ABCC1 G³¹⁷³ A (OR = 0.54, p = 0.04) polymorphism showed a lower incidence of developing nephrotoxicity. In ABCG2 C⁴²¹ A polymorphism, patients harboring heterozygous (CA) genotype had a lower incidence of having diarrhea (OR = 0.25, p = 0.04). An increased risk of having diarrhea was observed in the heterozygous genotype (GA) for ABCC1 G³¹⁷³ A polymorphism (AOR = 2.78, p = 0.04). An increased risk of liver injury was found in the patients carrying heterozygous genotype of the ABCC1 G³¹⁷³ A (OR = 2.06, p = 0.02) and ABCB1 C¹²³⁶ T (OR = 1.85, p = 0.01). This study demonstrates the role of polymorphic variations in ABCB1, ABCC1, ABCC2, and ABCG2 in predicting hematological, nephrotoxicity, gastrointestinal, and hepatotoxicity.

Targeting Mitochondrial IDH2 Enhances Antitumor Activity of Cisplatin in Lung Cancer via ROS-Mediated Mechanism

Mitochondrial isocitrate dehydrogenase 2 (IDH2) is an important metabolic enzyme in the tricarboxylic acid cycle (TCA) cycle. Our previous study showed that high expression of wild-type IDH2 promotes the proliferation of lung cancer cells. This study aims to test the potential of targeting IDH2 as a therapeutic strategy to inhibit lung cancer in vitro and in vivo. First, we analyzed the available data from the databases gene expression omnibus (GEO) database to evaluate the clinical relevance of IDH2 expression in affecting lung cancer patient survival. We then generated a stable IDH2-knockdown lung cancer cell line using a lentivirus-based method for in vitro and in vivo study. Cell growth, apoptosis, cell viability, and colony formation assays were conducted to test the sensitivity of lung cancer cells with different IDH2 expression status to cisplatin or radiation treatment in vitro. For mechanistic study, Cellular oxygen consumption and extracellular acidification rates were measured using a Seahorse metabolic analyzer, and reactive oxygen species (ROS) generation was analyzed using flow cytometry. An animal study using a xenograft tumor model was performed to further evaluate the in vivo therapeutic effect on tumor growth. We found that high IDH2 expression was associated with poor survival in lung cancer patients undergoing chemotherapy. Inhibition of IDH2 significantly enhanced the anticancer activity of cisplatin and also increased the effect of radiation against lung cancer cells. IDH2 was upregulated in cisplatin-resistant lung cancer cells, which could be sensitized by targeted inhibition of IDH2. Mechanistic study showed that abrogation of IDH2 caused only minimal changes in oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in lung cancer cells, but induced a significant increase in ROS, which rendered the cancer cells more sensitive to cisplatin. Pretreatment of lung cancer cells with the ROS scavenger N-acetyl-cysteine could partially rescue cells from the cytotoxic effect of cisplatin and IDH2 inhibition. Importantly, abrogation of IDH2 significantly increased the sensitivity of lung cancer cells to cisplatin in vivo.

Pharmacogenetics of Anticancer Drugs: Clinical Response and Toxicity

Cancer is the most challenging disease for medical professionals to treat. The factors underlying the complicated situation include anticancer drug-associated toxicity, non-specific response, low therapeutic window, variable treatment outcomes, development of drug resistance, treatment complications, and cancer recurrence. The remarkable advancement in biomedical sciences and genetics, over the past few decades, however, is changing the dire situation. The discovery of gene polymorphism, gene expression, biomarkers, particular molecular targets and pathways, and drug-metabolizing enzymes have paved the way for the development and provision of targeted and individualized anticancer treatment. Pharmacogenetics is the study of genetic factors having the potential to affect clinical responses and pharmacokinetic and pharmacodynamic behaviors of drugs. This chapter emphasizes pharmacogenetics of anticancer drugs and its applications in improving treatment outcomes, selectivity, toxicity of the drugs, and discovering and developing personalized anticancer drugs and genetic methods for prediction of drug response and toxicity.

Next-generation sequencing of homologous recombination genes could predict efficacy of platinum-based chemotherapy in non-small cell lung cancer

Background

With the widespread use of next-generation sequencing (NGS) in clinical practice, an increasing number of biomarkers that predict a response to anti-tumor therapy in non-small cell lung cancer (NSCLC) has been identified. However, validated biomarkers that can be used to detect a response to platinum-based chemotherapy remain unavailable. Several studies have suggested that homologous recombination deficiency (HRD) may occur in response to platinum-based chemotherapy in ovarian cancer and breast cancer. However, currently there is a lack of proven and reliable HRD markers that can be used to screen for patients who may benefit from platinum-based chemotherapy, especially in NSCLC.

Methods

NGS was used to screen for gene mutations, including homologous recombination (HR) genes and common driver gene mutations in NSCLC. Cox regression analysis was performed to identify potential clinicopathological or gene mutation factors associated with survival in patients receiving platinum-based chemotherapy, while Kaplan-Meier analysis with the log-rank test was performed to assess the effect of HR gene mutations on progression-free survival (PFS).

Results

In a retrospective cohort of 129 patients with advanced NSCLC, 54 who received platinum-based chemotherapy with or without anti-angiogenic therapy were included in the analysis. Univariate and multivariate Cox proportional hazard regression analyses showed that HR gene mutations were associated with platinum-based chemotherapy sensitivity. Efficacy results indicated that the objective response rates (ORR) for patients with BRCA1/2 mutations and BRCA1/2 wild type were 75% and 30.4% (p=0.041), while the median PFS was 7.5 and 5.5 months (hazard ratio [HR], 0.52; 95% CI, 0.27-1.00; p=0.084), respectively. The ORRs of patients with HR gene mutations and HR gene wild type were 60% and 23.6% (p=0.01), and the median PFS was 7.5 and 5.2 months (HR, 0.56; 95% CI, 0.32-0.97; p=0.033), respectively.

Conclusions

HR gene mutations show potential as promising biomarkers that may predict sensitivity to platinum-based chemotherapy in advanced and metastatic NSCLC.

Detection of netrin-1 as a novel biomarker for diagnosis and chemotherapeutic monitoring of lung cancer

Objective

Lung cancer has high morbidity and mortality. We aimed to determine the value of netrin-1 for the diagnosis and chemotherapeutic monitoring of lung cancer.

Methods

Thirty pairs of lung cancer tissues and serum were collected. Netrin-1 expression was detected by immunohistochemistry and enzyme-linked immunosorbent assay. Netrin-1 expression was downregulated in A549 cells using small interfering RNA, and the effect of netrin-1 on cisplatin-induced lung cancer cell apoptosis was determined by flow cytometry.

Results

Netrin-1-positivity was significantly higher in lung cancer tissues than in paracarcinoma tissues and high expression of netrin-1 was closely related to a poor prognosis. Serum netrin-1 levels were also significantly higher in lung cancer patients than in healthy donors, and were higher in patients with lung cancer before the beginning of chemotherapy compared with after the completion of four cycles of chemotherapy. Netrin-1 knockdown increased the rate of cisplatin-induced apoptosis in A549 cells.

Conclusions

Netrin-1 expression was increased in tissues and serum from lung cancer patients and decreased after chemotherapy, suggesting that it may be a potential diagnostic marker and indicator of chemosensitivity. Netrin-1 may participate in cisplatin resistance by reducing apoptosis, thus providing a new strategy for addressing chemoresistance in patients with lung cancer.

miR‑383 increases the cisplatin sensitivity of lung adenocarcinoma cells through inhibition of the RBM24‑mediated NF‑κB signaling pathway

The expression of microRNA-383 (miR-383) is downregulated in a variety of tumor tissues, and it exhibits antiproliferative activity in non-small cell lung cancer cells. In the present study, an association between the downregulation of miR-383 expression and the deletion of chr8p22 in patients with lung adenocarcinoma was identified. The promoting effect of miR-383 on cisplatin sensitivity was verified both in vivo and in vitro. Additionally, it was revealed that the expression of RNA binding motif protein 24 (RBM24) protein was regulated by and negatively correlated with miR-383 expression. Ectopic expression of RBM24 or inhibition of miR-383 decreased the chemosensitivity of parental A549 cells, whereas knockdown of RBM24 in cisplatin-resistant A549 cells increased chemosensitivity. Mechanistically, miR-383 interfered with the activation of nuclear factor κB (NF-κB) signaling through repression of RBM24-mediated phosphorylation of Rel-like domain-containing protein A and inhibitor α of NF-κB. Taken together, the downregulation of miR-383 induced RBM24 expression, which was mediated through the activation of NF-κB signaling, to contribute to chemotherapy resistance in lung adenocarcinoma cells. The results of the present study highlight potential therapeutic targets for the clinical reversal of the chemotherapy resistance in lung adenocarcinoma.

Complex analysis of the personalized pharmacotherapy in the management of COVID-19 patients and suggestions for applications of predictive, preventive, and personalized medicine attitude

Aims

Coronavirus disease 2019 (COVID-19) is rapidly spreading worldwide. Drug therapy is one of the major treatments, but contradictory results of clinical trials have been reported among different individuals. Furthermore, comprehensive analysis of personalized pharmacotherapy is still lacking. In this study, analyses were performed on 47 well-characterized COVID-19 drugs used in the personalized treatment of COVID-19.

Methods

Clinical trials with published results of drugs use for COVID-19 treatment were collected to evaluate drug efficacy. Drug-to-Drug Interactions (DDIs) were summarized and classified. Functional variations in actionable pharmacogenes were collected and systematically analysed. “Gene Score” and “Drug Score” were defined and calculated to systematically analyse ethnicity-based genetic differences, which are important for the safer use of COVID-19 drugs.

Results

Our results indicated that four antiviral agents (ritonavir, darunavir, daclatasvir and sofosbuvir) and three immune regulators (budesonide, colchicine and prednisone) as well as heparin and enalapril could generate the highest number of DDIs with common concomitantly utilized drugs. Eight drugs (ritonavir, daclatasvir, sofosbuvir, ribavirin, interferon alpha-2b, chloroquine, hydroxychloroquine (HCQ) and ceftriaxone had actionable pharmacogenomics (PGx) biomarkers among all ethnic groups. Fourteen drugs (ritonavir, daclatasvir, prednisone, dexamethasone, ribavirin, HCQ, ceftriaxone, zinc, interferon beta-1a, remdesivir, levofloxacin, lopinavir, human immunoglobulin G and losartan) showed significantly different pharmacogenomic characteristics in relation to the ethnic origin of the patient.

Conclusion

We recommend that particularly for patients with comorbidities to avoid serious DDIs, the predictive, preventive, and personalized medicine (PPPM, 3 PM) strategies have to be applied for COVID-19 treatment, and genetic tests should be performed for drugs with actionable pharmacogenes, especially in some ethnic groups with a higher frequency of functional variations, as our analysis showed. We also suggest that drugs associated with higher ethnic genetic differences should be given priority in future pharmacogenetic studies for COVID-19 management. To facilitate translation of our results into clinical practice, an approach conform with PPPM/3 PM principles was suggested. In summary, the proposed PPPM/3 PM attitude should be obligatory considered for the overall COVID-19 management.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-021-00247-0.

The influence of genetic polymorphisms on the toxicity of platinum-based chemotherapy in the treatment of non-small cell lung cancer

Lung cancer remains one of the most frequent and the deadliest of malignant diseases throughout the world. Target and immune therapy have revolutionalized the treatment of this disease, but platinum-based chemotherapy still has a place in the treatment algorithm. The toxicity profile of cisplatin is well known and can be a limiting factor in the adequate treatment delivery of the drug. There are important inter-individual differences in the efficacy and the toxicity of all chemotherapy drugs, which cannot be explained solely by the characteristics of the tumor. In order to define predictive factors for the occurrence of toxic effects, numerous genetic alterations have been investigated - especially single nucleotide polymorphisms (SNPs). The investigated genes are those involved in DNA repair mechanisms, signal pathways of apoptosis, DNA synthesis, transport mechanisms, but often with inconclusive and opposing results. It is clear that the effect of SNPs on the occurrence of cisplatin toxicity cannot be explained by investigating just one or several genes alone, but epigenetic interactions must be investigated, as well as interactions with outside factors. The study of SNPs is, however, a relatively simple and inexpensive method and, as such, can be used as one of the prognostic tools for everyday practice.

Genetic Polymorphisms and the Efficacy of Platinum-Based Chemotherapy: Review

Previous studies have indicated that genetic variations in individuals may result in changes in gene expression and amino acids. The effect of these changes may lead to different responses to platinum-based chemotherapy. A vast response rate interval and a short survival rate indicate that the efficacy and efficiency of the selection of chemotherapy have not been optimized. This article aims to illustrate the potential relationship of various genetic polymorphisms in response to platinum-based chemotherapy for several types of cancer. This review was conducted using articles from the last three- and five-year periods (2014-2019) that use gene polymorphism and its relationship to the efficacy of platinum-based chemotherapy as their theme. A total of 26 out of 488 relevant articles were included based on specific criteria. Through various mechanisms, genes, including ERCC1, ERCC2/XPD, XPC, XPA, XRCC1, APE-1, PARP1, OGG1, ABCC2, MRP, GSTP1, GSTM1, GSTT1, MATE1, and OCT2, have been associated with patient response to platinum-based chemotherapy. We conclude that genetic polymorphism analysis is recommended for the management of cancer so that each patient can be administered therapy based on his or her genetic profile to achieve an effective and efficient outcome.

Sequential Whole Exome Sequencing Reveals Somatic Mutations Associated with Platinum Response in NSCLC

Purpose

Resistance is one of the main limitations of successful platinum treatment in non-small-cell lung cancer (NSCLC) patients. In this study, we aimed to identify somatic mutations associated with platinum response.

Patients and Methods

A total of 57 patients who received platinum-based chemotherapy only and 13 patients who received neoadjuvant chemotherapy (NAC) were enrolled. Somatic mutations were obtained from targeted and whole exome sequencing (WES).

Results

Somatic mutations in a total of 225 genes were observed. Nonsynonymous variants in EGFR, TTN, TP53 and KRAS, and copy number variations (SCNVs) in chromosome 8q24.3 and 22q11.21 were identified to be associated with platinum response. Based on these mutations, the mutational signature associated with the failure of DNA double-strand break and calcium signaling pathways were identified to be associated with platinum response. Besides, we observed a decrease in tumor mutational burden after chemotherapy. We also evaluated the mutation spectrum consistency between cell-free DNA (cfDNA) and tissue DNA. Somatic mutations detected in cfDNA were consistent with that in tDNA, which indicated that plasma might be used for somatic mutation detection.

Conclusion

These results support that somatic mutations can affect platinum drug response and provide potential clinical biomarkers for NSCLC treatment.

Genetic Polymorphisms and Platinum-Based Chemotherapy-Induced Toxicities in Patients With Lung Cancer: A Systematic Review and Meta-Analysis

Background: Platinum-based agents, including cisplatin, carboplatin, and oxaliplatin, are indispensable for the treatment of lung cancer. The development of toxicity frequently necessitates dose reduction or discontinuation of therapy, despite the clinical response. Pharmacogenomics studies were reviewed to identify the possible genetic variants that underlie individual susceptibility to platinum-related toxicities. Method: We conducted a systematic search in PubMed and Embase for pharmacogenomics reports that focused on commonly reported platinum-induced toxicities, such as gastrointestinal (GI), hematological, neurological, and other toxicities, in patients diagnosed with lung cancer. Meta-analyses were conducted to determine the association between genetic polymorphisms and platinum-induced toxicity by checking the odds ratio (OR) and 95% confidence interval (CI) using random or fixed-effects models as appropriate. Results: Twenty eligible studies that met the inclusion criteria with sufficient data were extracted and presented comprehensively. A total of 16 polymorphisms from 11 genes were included in the meta-analysis. MTHFR rs1801131 and MDM2 rs1690924 were significantly correlated with platinum-induced GI toxicity (P = 0.04 and P = 0.02, respectively). Patients with the MTHFR rs1801131AA and MDM2 rs1690924TC/CC genotype tended to have a higher risk of GI toxicity than patients with other genotypes did (OR = 1.73, 95% CI = 0.86-2.18; and OR = 0.51, 95% CI = 0.29-0.88, respectively). Compared to carriers of the MTHFR rs1801133CC genotype, carriers of the CT/TT genotype had a significantly increased risk of hematological toxicity (P = 0.01, OR = 1.68, 95% CI = 1.12-2.52). Conclusion: In the future, physicians should pay careful attention to MTHFR and MDM2 for personalized chemotherapy treatment among patients with lung cancer.

Pharmacogenomics for the efficacy of platinum-based chemotherapy: Old drugs, new integrated perspective

Platinum-based chemotherapy remains the cornerstone of treatment for many malignancies. However, although therapeutic efficiency varies greatly among individuals, there is a lack of pharmacogenomic biomarkers that can be used in clinical settings to identify chemosensitive patients and allow stratification. With the development of high-throughput screening techniques and systems biology approaches, a growing body of evidence has shown that platinum resistance is a multifactorial, multi-dimensional, dynamic process incorporating genetic background, tumor evolution and gut microbes. This review critically summarizes potential pharmacogenomic biomarkers for predicting the efficacy of platinum drugs and provides a comprehensive, time-varying perspective that integrates multiple markers.

Association of variations in platinum resistance-related genes and prognosis in lung cancer patients

Purpose: We aimed to investigate the association of single-nucleotide polymorphisms (SNPs) in HMGB1, REV3L, and NFE2L2 with prognosis in lung cancer patients with platinum-based chemotherapy. Methods: We have recruited 348 lung cancer patients treated with platinum. Log-rank test and Cox regression analysis were used to assess overall survival (OS) and progression-free survival (PFS) among SNP genotypes. Results: The results revealed that patients carrying TC or CC genotype in REV3L rs462779 (HR=0.67, 95% CI=0.51-0.90, P=0.007) and AG or GG genotype in HMGB1 rs1045411 (HR=0.61, 95% CI=0.38-0.99, P=0.046) had a better overall survival. Additionally, carrying TC or TT genotype in rs462779 had a lower risk (OR=0.38, 95% CI=0.17-0.89, P=0.025) of lymph node metastasis, carrying AG or AA genotype in rs1045411 was significantly related to early T stage (OR=0.47, 95% CI=0.29-0.76, P=0.002). In stratified analysis, patients with TC or CC genotype in rs462779 were significantly associated with overall survival in male patients, never-smokers, patients with younger age (≤56), no family history of cancer, adenocarcinoma, advanced stage (stage III or IV), or ECOG PS 0-1. While patients with AG or GG genotype in rs1045411 were significantly associated with overall survival in patients with advanced stage (stage III or IV) or ECOG PS 0-1. Conclusion: Our results indicate that the TC or CC genotype in rs462779 and AG or GG genotype in rs1045411 are contributed to better overall survival. The REV3L rs462779 and HMGB1 rs1045411 may serve as prognosis markers in lung cancer patients with platinum-based chemotherapy.

AFAP1-AS1 induces cisplatin resistance in non-small cell lung cancer through PI3K/AKT pathway

Cisplatin (DDP)-resistance in non-small cell lung carcinoma (NSCLC) severely influences the prognosis of affected patients. This study aims to uncover the potential role of AFAP1-AS1 in DDP-resistant NSCLC and the underlying mechanism. The expression level of AFAP1-AS1 in DDP-resistant NSCLC patients and DDP-resistant A549 cells (A549/DDP) was determined. Proliferative, cell cycle distribution, apoptotic, migratory and invasive changes in A549/DDP cells transfected with si-AFAP1-AS1 were assessed. Western blot analyses were conducted to examine the protein levels of phosphorylated protein kinase B (p-AKT), AKT, E-cadherin, N-cadherin, vimentin and snail in A549/DDP cells. Furthermore, the ubcellular distribution of AFAP1-AS1 was analyzed. Through RNA immunoprecipitation (RIP) assay, the interaction between AFAP1-AS1 and enhancer of zeste homolog 2 (EZH2) was explored. Finally, the regulatory effect of EZH2 on the PI3K/AKT pathway was investigated by western blot analysis. AFAP1-AS1 was upregulated in DDP-resistant NSCLC patients and A549/DDP cells. Transfection with si-AFAP1-AS1 attenuated the proliferative, migratory and invasive abilities, arrested cell cycle in G0/G1 phase, and stimulated apoptosis of A549/DDP cells. Silencing of AFAP1-AS1 upregulated E-cadherin and downregulated N-cadherin, vimentin and snail expression levels. Furthermore, AFAP1-AS1 was verified to interact with EZH2. The relative expression of EZH2 was reduced by transfection of A549/DDP cells with si-AFAP1-AS1. Silencing of EZH2 inhibited the activation of PI3K/AKT pathway. In conclusion, AFAP1-AS1 accelerates the proliferative and metastatic abilities of A549/DDP cells, whereas inhibits the apoptosis of A549/DDP cells, by interacting with EZH2 to activate the PI3K/AKT pathway; thus, inducing DDP resistance in NSCLC.

CLEC4M is associated with poor prognosis and promotes cisplatin resistance in NSCLC patients

Cisplatin-based chemotherapy is the foundation of treatment for major non-small cell lung cancer (NSCLC) patients. However, cisplatin resistance is still a challenging issue, and the molecular mechanisms underlying this resistance remain to be fully explored. CLEC4M, a Ca²⁺-dependent C-type lectin, has recently been found to correlate with tumourigenesis. This study mainly focused on whether CLEC4M impacts clinical prognosis and how CLEC4M contributes to cisplatin resistance in NSCLC. Our results found that CLEC4M was correlated with poor prognosis in patients with lung cancer. In addition, a positive association between CLEC4M expression and the IC50 values of cisplatin was found, which suggests that CLEC4M may impact cisplatin sensitivity. In vitro results from cultured A549 and H1299 cells confirmed that CLEC4M could enhance cisplatin resistance, while CLEC4M knockdown led to higher sensitivity to cisplatin in these cells. Further experiments showed that the underlying mechanisms included inhibition of cisplatin-induced cell apoptosis by CLEC4M and improved DNA repair capacity by upregulating XPA and ERCC1 expression. In addition, CLEC4M was able to promote cell migration with or without cisplatin treatment. Collectively, these findings suggest the potential clinical significance of CLEC4M inhibition in overcoming cisplatin resistance in NSCLC patients.

Alisol B 23‑acetate inhibits the viability and induces apoptosis of non‑small cell lung cancer cells via PI3K/AKT/mTOR signal pathway

The aim of the present study was to investigate the effects of alisol B 23‑acetate (AB23A) on inhibiting the viability and inducing apoptosis of human non‑small cell lung cancer (NSCLC) cells and the anticancer mechanisms of AB23A in vitro. The viability of A549 cells following treatment with different doses of AB23A was examined using a Cell Counting Kit‑8 assay. Subsequently, apoptosis and the cell cycle were detected using flow cytometric analysis. The effect of AB23A on migration and invasion of A549 cells was detected by wound healing and Transwell assays. Western blotting was performed to determine the relative expression of Bax/Bcl‑2, phosphatidylinositol 3‑kinase (PI3K), protein kinase B (AKT) and mammalian target of rapamycin (mTOR). AB23A markedly inhibited the viability enhanced apoptosis of A549 cells and arrested the cell cycle in G1 phase. Additionally, AB23A upregulated the ratio of Bax/Bcl‑2 in the A549 cells in a concentration‑dependent manner. The results of wound healing and Transwell assays indicated that AB23A also suppresses the migration and invasion ability of A549 cells. Furthermore, AB23A reduced the protein levels of phosphorylated AKT, PI3K and mTOR. In conclusion, AB23A exerted anti‑cancer activity via inhibiting cells viability, migration and invasion, and promoting apoptosis. Therefore, AB23A is a potential antitumor drug for the treatment of NSCLC.

Outcome Definition Influences the Relationship Between Genetic Polymorphisms of ERCC1, ERCC2, SLC22A2 and Cisplatin Nephrotoxicity in Adult Testicular Cancer Patients

Although previous research identified candidate genetic polymorphisms associated with cisplatin nephrotoxicity, varying outcome definitions potentially contributed to the variability in the effect size and direction of this relationship. We selected genetic variants that have been significantly associated with cisplatin-induced nephrotoxicity in more than one published study (SLC22A2 rs316019; ERCC1 rs11615 and rs3212986; ERCC2 rs1799793 and rs13181) and performed a replication analysis to confirm associations between these genetic polymorphisms and cisplatin nephrotoxicity using various outcome definitions. We included 282 germ cell testicular cancer patients treated with cisplatin from 2009-2014, aged >17 years recruited by the Canadian Pharmacogenomics Network for Drug Safety. Nephrotoxicity was defined using four grading tools: (1) Common Terminology Criteria for Adverse Events (CTCAE) v4.03 for acute kidney injury (AKI) or CTCAE-AKI; (2) adjusted cisplatin-induced AKI; (3) elevation of serum creatinine; and (4) reduction in the estimated glomerular filtration rate (eGFR). Significant associations were only found when using the CTCAE v4.03 definition: genotype CA of the ERCC1 rs3212986 was associated with decreased risk of cisplatin nephrotoxicity (ORadj = 0.24; 95% CI:0.08-0.70; p= 0.009) compared to genotype CC. In contrast, addition of allele A at SLC22A2 rs316019 was associated with increased risk (ORadj = 4.41; 95% CI:1.96-9.88; p < 0.001) while genotype AC was associated with a higher risk of cisplatin nephrotoxicity (ORadj = 5.06; 95% CI:1.69-15.16; p= 0.004) compared to genotype CC. Our study showed that different case definitions led to variability in the genetic risk ascertainment of cisplatin nephrotoxicity. Therefore, consensus on a set of clinically relevant outcome definitions that all such studies should follow is needed.

3-deazaneplanocin A protects against cisplatin-induced renal tubular cell apoptosis and acute kidney injury by restoration of E-cadherin expression

3-deazaneplanocin A (3-DZNeP) has been used as an inhibitor of enhancer of zeste homolog 2 (EZH2). Here, we explore the role and underlying mechanisms action of 3-DZNeP in abrogating cisplatin nephrotoxicity. Exposure of cultured mouse renal proximal tubular epithelial cells (mTECs) to cisplatin resulted in dose and time-dependent cleavage of caspase-3, decrease of cell viability, and increase of histone H3 lysine 27 trimethylation (H3K27me3), whereas expression levels of EZH2, a major methyltransferase of H3K27me3, were not affected. Treatment with 3-DZNeP significantly inhibited cisplatin-induced activation of caspase-3, apoptosis, loss of cell viability but did not alter levels of EZH2 and H3K27me3 in cultured mTECs. 3-DZNeP treatment did not affect activation of extracellular signal-regulated kinase (ERK) 1/2, p38 or c-Jun N-terminal kinases (JNK) 1/2, which contribute to renal epithelial cell death, but caused dose-dependent restoration of E-cadherin in mTECs exposed to cisplatin. Silencing of E-cadherin expression by siRNA abolished the cytoprotective effects of 3-DZNeP. In contrast, 3-DZNeP treatment potentiated the cytotoxic effect of cisplatin in H1299, a non-small cell lung cancer cell line that expresses lower E-cadherin levels. Finally, administration of 3-DZNeP attenuated renal dysfunction, morphological damage, and renal tubular cell death, which was accompanied by E-cadherin preservation, in a mouse model of cisplatin nephrotoxicity. Overall, these data indicate that 3-DZNeP suppresses cisplatin-induced tubular epithelial cell apoptosis and acute kidney injury via an E-cadherin-dependent mechanism, and suggest that combined application of 3-DZNeP with cisplatin would be a novel chemotherapeutic strategy that enhances the anti-tumor effect of cisplatin and reduces its nephrotoxicity.

Effect of RIF1 on response of non-small-cell lung cancer patients to platinum-based chemotherapy by regulating MYC signaling pathway

Platinum-based chemotherapy is used as first-line therapy for advanced non-small-cell lung cancer (NSCLC). However, there is no effective indicator to predict whether the patient would be chemo-resistant or sensitive to the therapy. In addition, it is urgent to elucidate the mechanisms of cisplatin resistance. RIF1 plays important roles in DNA replication regulation and DNA repair pathway. However, the role of RIF1 in NSCLC progression and chemotherapy response is still unknown. In this study, we found that RIF1 expression was correlated with the response of NSCLC patients to platinum-based chemotherapy (n=89, P=0.002). Among patients who have been treated with platinum chemo-therapy, those with high levels of RIF1 expression had significantly shorter survival than those with low RIF1 expression (P<0.05). RIF1 knockdown increased sensitivity to cisplatin in NSCLC patients both in vitro and in vivo. Moreover, RIF1 knockdown induced G0/G1 phase arrest and increased cisplatin-induced apoptosis and DNA damage. Further investigation showed that RIF1 regulated the expression of MYC and MYC downstream targets, including the cell cycle and double-stranded break (DSB) repair genes which might mediate the effect of RIF1 on cellular response to cisplatin. Overexpression of MYC could reverse the inhibition of MYC targets by RIF1 knockdown. Taken together, these data revealed that RIF1 played an important role in regulating MYC and MYC-activated genes, which in turn contributes to cellular response to cisplatin and NSCLC patients' response to platinum-based chemotherapy. RIF1 might serve as a novel biomarker for predicting platinum-based chemo-sensitivity and the prognosis of NSCLC patients, so as to guide the chemotherapy regimen adjustment for individual patient with NSCLC and improve their clinical outcomes.

NEAT1 contributes to the CSC-like traits of A549/CDDP cells via activating Wnt signaling pathway

Long non-coding RNAs (lncRNAs) have been identified to exert crucial roles in tumorigenesis and can serve as novel biomarkers for cancer therapy including lung cancer. Cisplatin is a first-line chemotherapeutic agent in non-small cell lung cancer (NSCLC), but the therapeutic effect is unsatisfactory, partly due to drug resistance. Emerging evidence showed that chemo-resistance is associated with acquisition of cancer stem cell (CSC)-like properties. Cisplatin resistance remains a major obstacle in the treatment of lung cancer, and its mechanism is still not fully elucidated. Meanwhile, CSCs have been involved in tumor metastasis, tumor recurrence and chemotherapy resistance. So far, the mechanism of nuclear enriched abundant transcript 1 (NEAT1) in modulating CSCs in lung cancer remains barely known. Therefore, we aimed to explore the correlation between NEAT1 and cancer stem cells in lung cancer. In our current study, we observed that CSC-like traits were much more enriched in cisplatin-resistant A549/CDDP cells. In addition, NEAT1 was obviously up-regulated in A549/CDDP cells compared with parental A549 cells. Knockdown of NEAT1 decreased the CSC-like properties of A549/CDDP cells through inhibiting tumor cell sphere volume, repressing CSC-like biomarkers levels and restraining CD44 positive cell ratios. Oppositely, overexpression of NEAT1 enhanced the stemness respectively. Moreover, it has been reported that Wnt pathway is implicated in many vital cellular functions including cancer stem cells. Here, it was exhibited that Wnt signal pathway was inactivated by knockdown of NEAT1 whereas activated by NEAT1 overexpression in A549/CDDP cells. Taken these together, it was indicated that NEAT1 could exert a novel biological role in NSCLC chemo-resistance.

Genetic Variations and Cisplatin Nephrotoxicity: A Systematic Review

Background: Nephrotoxicity is a notable adverse effect in cisplatin treated patients characterized by tubular injury and/or increased serum creatinine (SCr) with incidence varying from 20 to 70%. Pharmacogenomics has been shown to identify strongly predictive genetic markers to help determine which patients are more likely to experience, for example, a serious adverse drug reaction or receive optimal benefit through enhanced efficacy. Genetic variations have been reported to influence the risk of cisplatin nephrotoxicity; however, a comprehensive overview is lacking. Methods: A systematic review was performed using Pubmed, Embase and Web of Science on clinical studies that used cisplatin-based chemotherapy as treatment, had available genotyping data, and evaluated nephrotoxicity as an outcome. The quality of reporting was assessed using the STrengthening the REporting of Genetic Association Studies (STREGA) checklist. Results: Twenty-eight eligible studies were included; all were candidate gene studies. Over 300 SNPs across 135 genes were studied; 29 SNPs in 14 genes were significantly associated with cisplatin-induced nephrotoxicity. A variation in SLC22A2 rs316019, a gene involved in platinum uptake by the kidney, was associated with different measures of nephrotoxicity in four independent studies. Further, variants of ERCC1 (rs11615 and rs3212986) and ERCC2 (rs13181), two genes involved in DNA repair, were found to be positively associated with increased risks of nephrotoxicity in two independent studies. Conclusion: Three genes consistently associated with cisplatin-induced nephrotoxicity. Further research is needed to assess the biological mechanism and the clinical value of modifying treatment based on SLCC22A2 and ERCC1/2 genotypes.

RANBP9 affects cancer cells response to genotoxic stress and its overexpression is associated with worse response to platinum in NSCLC patients

Although limited by severe side effects and development of resistance, platinum-based therapies still represent the most common first-line treatment for non-small cell lung cancer (NSCLC). However, a crucial need in the clinical management of NSCLC is represented by the identification of cases sensitive to DNA damage response (DDR)-targeting drugs, such as cisplatin or PARP inhibitors. Here, we provide a molecular rationale for the stratification of NSCLC patients potentially benefitting from platinum compounds based on the expression levels of RANBP9, a recently identified player of the cellular DDR. RANBP9 was found overexpressed by immunohistochemistry (IHC) in NSCLC compared to normal adjacent tissues (NATs) (n = 147). Moreover, a retrospective analysis of 132 platinum-treated patients from the multi-centric TAILOR trial showed that RANBP9 overexpression levels are associated with clinical response to platinum compounds [Progression Free Survival Hazard Ratio _{(RANBP9 high vs low)} 1.73, 95% CI 1.15-2.59, p = 0.0084; Overall Survival HR _{(RANBP9 high vs low)} 1.99, 95% CI 1.27-3.11, p = 0.003]. Accordingly, RANBP9 KO cells showed higher sensitivity to cisplatin in comparison with WT controls both in vitro and in vivo models. NSCLC RANBP9 KO cells were also more sensitive than control cells to the PARP inhibitor olaparib alone and in combination with cisplatin, due to defective ATM-dependent and hyper-activated PARP-dependent DDR. The current investigation paves the way to prospective studies to assess the clinical value of RANBP9 protein levels as prognostic and predictive biomarker of response to DDR-targeting drugs, leading to the development of new tools for the management of NSCLC patients.

Traditional Chinese Medicine Integrated with Chemotherapy for Stage II-IIIA Patients with Non-Small-Cell Lung Cancer after Radical Surgery: A Retrospective Clinical Analysis with Small Sample Size

Objective

This study was designed to evaluate the clinical efficacy of combined traditional Chinese medicine (TCM) and conventional chemotherapy versus conventional chemotherapy in patients with stage II-IIIA non-small-cell lung cancer (NSCLC) after radical surgery.

Methods

A retrospective cohort study was conducted in patients with stage II-IIIA NSCLC from Subei People's Hospital and Yangzhou Traditional Chinese Medicine Hospital in Yangzhou City of Jiangsu Province from 2012 to 2016. Patients were divided into two groups: the TCM user group (patients receiving treatment with integrated TCM and conventional chemotherapy) and the non-TCM user group (patients receiving conventional chemotherapy only). The two groups were compared for their median disease-free survival (DFS) and median overall survival (OS).

Results

A total of 67 patients with stage II-IIIA NSCLC were enrolled between January 2012 and December 2016. The median DFS for the non-TCM user group was 601 days (95% confidence interval [CI], 375.7-826.3). The median DFS for TCM user group could not be calculated. However, log-rank analysis showed that the median survival time in the TCM user group was significantly longer than that of the non-TCM user group (P < 0.05). In addition, several significant risk factors were detected for predicting disease prognosis in patients with NSCLC, such as age, ECOG, lymphatic metastasis, and body mass index (BMI). For patients harboring these independent risk factors, the DFS of TCM user group was much longer than that of non-TCM user group (P < 0.05).

Conclusion

Adjuvant therapy with TCM may reduce the rate of tumor recurrence and metastasis and prolong DFS of patients with stage II-IIIA NSCLC.

Proliferating cell nuclear antigen promotes cell proliferation and tumorigenesis by up-regulating STAT3 in non-small cell lung cancer

Proliferating cell nuclear antigen (PCNA) functions as a bridging molecule, which targets proteins that have distinct roles in cell growth. The expression of PCNA is dysregulated in some tumors and takes part in the progression of oncogenesis. However, the roles of PCNA in the progression of non-small cell lung cancer (NSCLC) remain unknown. The present study aimed to investigate the function of PCNA in the occurrence and development of NSCLC and its underlying molecular mechanisms. Western blotting, RT-PCR, and immunohistochemistry assays were used to detect the expression pattern of PCNA in NSCLC tissues and cells. A log rank test was performed to compare the overall survival (OS) of patients with high/low expression of PCNA. Besides, the relationship between PCNA and signal transducer and activator of transcription-3 (STAT3) proteins were evaluated. Then, MTT, flow cytometry, clonal formation, and in vivo xenograft assays were conducted to investigate the effects of PCNA/STAT3 on cell growth, clonal formation, apoptosis, and tumorigenesis. Results showed that PCNA expression was elevated in NSCLC tissues and cells and it could combine with STAT3 and increased its expression and phosphorylation. Moreover, the expression of PCNA showed a positive correlation with the TNM grade and occurrence rate of the lymphatic metastasis and poor prognosis of NSCLC patients. Overexpression of PCNA promoted cell proliferation, clonal formation, and tumorigenesis in lung cancer cells and inhibited cell apoptosis. In contrast, these effects were inhibited when knockdown of STAT3. In conclusion, this study demonstrates that PCNA functions as an oncogene in the progression of NSCLC through up-regulation of STAT3. These findings point to a potentially new therapeutic strategy for NSCLC.

Acetyl-macrocalin B, an ent-kaurane diterpenoid, initiates apoptosis through the ROS-p38-caspase 9-dependent pathway and induces G2/M phase arrest via the Chk1/2-Cdc25C-Cdc2/cyclin B axis in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide, and novel effective drugs against NSCLC are urgently needed. Isodon species are rich in ent-kaurane diterpenoids that have been reported to have antitumor bioactivity. Acetyl-macrocalin B (A-macB) is a novel ent-kaurane diterpenoid isolated from Isodon silvatica, and its antitumor efficacy against NSCLC and the underlying mechanisms were scrutinized in depth. The viability of cells treated with A-macB was detected by CCK-8 and colony formation assays. Apoptosis and cell cycle distribution were analyzed by flow cytometry. The mechanisms were investigated by detecting ROS and performing western blotting and verification experiments with specific inhibitors. The in vivo effect of A-macB was explored in a nude mouse xenograft model. A-macB effectively inhibited H1299 and A549 cell viability, triggered apoptosis and delayed cells in the G2/M phase. A-macB induced cellular ROS production and then activated the p38 MAPK-mediated, caspase 9-dependent apoptotic pathway. Both the ROS scavenger NAC and the specific p38 inhibitor SB203580 inactivated the function of p38 induced by A-macB, thus preventing cells from apoptosis. A-macB activated the Chk1/2-Cdc25C-Cdc2/cyclin B1 axis to induce G2/M phase arrest. AZD7762 abrogated the function of Chk1/2, abolished the G2/M delay and enhanced the cytotoxicity of A-macB. Moreover, A-macB efficiently suppressed tumor growth in a mouse xenograft model without noticeable toxicity to normal tissues. Having both efficacy and relative safety, A-macB is a potential lead compound that is worthy of further exploration for development as an anticancer agent.

A novel tetrahydroisoquinoline (THIQ) analogue induces mitochondria-dependent apoptosis

Lung cancer continues to be a leading cause of cancer-related death worldwide, with non-small cell lung cancer (NSCLC) accounting for more than 80% of lung cancer cases. Current therapies for NSCLC have only limited effect and treatment resistance develops rapidly. In a previous study, we have shown that C₁-phenylethynyl tetrahydroisoquinoline (THIQ) analogue 4 has anti-proliferative activity against PC3 human prostate cancer cells. However, this anticancer effect was achieved with relatively high IC₅₀ in A549 lung cancer cells. To improve the potency of the drug, in the present study, a series of novel THIQ analogues (analogues 5a-d) were prepared by using an oxidative C-H functionalization strategy, and their potential anticancer activities on A549 lung cancer cells were investigated. Among these analogues, analogue 5c can markedly inhibit A549 cell proliferation in a dose-dependent manner with a reasonable IC₅₀ of 14.61 ± 1.03 μM. This effect was mediated by analogue 5c-induced G0/G1 phase arrest and cell apoptosis. Treatment with analogue 5c was shown to induce reactive oxygen species (ROS) accumulation, disruption of mitochondrial membrane potential, reduction of glutathione, elevation of intracellular calcium ion (Ca²⁺), and activation of Caspase-3. Furthermore, analogue 5c can lead to DNA double-strand break and the activation of p53 pathway in A549 cells. In conclusion, the oxidative C-H functionalization strategy to generate analogue 5c could improve the drug anticancer efficacy by inducing mitochondria-dependent apoptosis in A549 cells.

Downregulated CDKN1C/p57kip2 drives tumorigenesis and associates with poor overall survival in breast cancer

CDKN1C, also known as p57^kip2, is considered to be a potential tumor suppressor implicated in several kinds of human cancers. However, the current knowledge of CDKN1C in breast cancer remains obscure. In the present study, we demonstrated that CDKN1C was dramatically downregulated in breast cancer compared with normal tissues by using real-time quantitative polymerase chain reaction, western blot and two public data portals: The Cancer Genome Atlas (TCGA) and Oncomine datasets. Moreover, the expression of CDKN1C was correlated with age and tumor size in the TCGA cohort containing 708 cases of breast cancer. Low expression of CDKN1C was significantly associated with poor overall survival (OS) in the TCGA cohort and validated cohort composed of 1402 patients. Multivariate Cox regression analysis indicated that CDKN1C was an independent prognostic factor for worse OS (HR = 1.78, 95% CI: 1.09-2.89, p = 0.020). Furthermore, gene set enrichment analysis (GSEA) revealed that CDKN1C was significantly correlated with gene signatures involving DNA repair, cell cycle, glycolysis, adipogenesis, and two critical signaling pathways mTORC1 and PI3K/Akt/mTOR. In conclusion, our data suggested an essential role of CDKN1C in the tumorgenesis of breast cancer. Targeting CDKN1C may be a promising strategy for anticancer therapeutics.

Pharmacogenetics of platinum-based chemotherapy in non-small cell lung cancer: predictive validity of polymorphisms of ERCC1

INTRODUCTION

The efficacy of platinum-based chemotherapy for patients with non-small cell lung cancer (NSCLC) is limited by chemoresistance. Platinum drugs damage DNA by introducing intrastrand and interstrand crosslinks which result in cell death. Excision repair cross-complementing 1 (ERCC1) is a member of the nucleotide excision repair (NER) pathway which erases such defects. Single nucleotide polymorphisms (SNPs) in ERCC1 impair this activity and have been suggested to predict the response to chemotherapy. Area covered: Among the polymorphisms of proteins involved in uptake, metabolism, cytotoxicity and efflux of platinum drugs, codon 118 C/T and C8092A in ERCC1 are the best characterized SNPs studied for their predictive power. Here, the divergent results for studies of these markers in NSCLC are summarized and the reasons for this contradictory data discussed. Expert opinion: Cytotoxicity of platinum compounds comprise complex cellular processes for which DNA repair may not constitute the rate limiting step. These drugs are administered as doublets to histologically diverse patients and, furthermore, the NER pathway in ERCC1 wildtype cohorts may be still impaired by the chemotherapeutics applied. At present, assessment of a limited number of polymorphism in DNA repair proteins is not reliably associated with response to treatment in NSCLC patients.

[Impairment of DNA damage response and cancer]

Maintaining the genetic integrity is a key process in cell viability and is enabled by a wide network of repair pathways. When this system is defective, it generates genomic instability and results in an accumulation of chromosomal aberrations and mutations that may be responsible for various clinical phenotypes, including susceptibility to develop cancer. Indeed, these defects can promote not only the initiation of cancer, but also allow the tumor cells to rapidly acquire mutations during their evolution. Several genes are involved in these damage repair systems and particular polymorphisms are predictive of the onset of cancer, the best described of them being BRCA. In addition to its impact on carcinogenesis, the DNA damage repair system is now considered as a therapeutic target of choice for cancer treatment, as monotherapy or in combination with other cytotoxic therapies, such as chemotherapies or radiotherapy. PARP inhibitors are nowadays the best known, but other agents are emerging in the field of clinical research. The enthusiasm in this area is coupled with promising results and a successful collaboration between clinicians and biologists would allow to optimize treatment plans in order to take full advantage of the DNA repair system modulation.

Design, synthesis and biological evaluation of novel benzimidazole amidines as potent multi-target inhibitors for the treatment of non-small cell lung cancer

A series of novel amidino 2-substituted benzimidazoles linked to 1,4-disubstituted 1,2,3-triazoles were synthesized by implementation of microwave and ultrasound irradiation in click reaction and subsequent condensation of thus obtained 4-(1,2,3-triazol-1-yl)benzaldehyde with o-phenylenediamines. In vitro antiproliferative screening of compounds performed on human cancer cell lines revealed that p-chlorophenyl-substituted 1,2,3-triazolyl N-isopropylamidine 10c and benzyl-substituted 1,2,3-triazolyl imidazoline 11f benzimidazoles had selective and potent cytostatic activities in the low nM range against non-small cell lung cancer cell line A549, which could be attributed to induction of apoptosis and primary necrosis. Additional Western blot analyses showed different mechanisms of cytostatic activity between compounds 10c and 11f that could be associated with the nature of aromatic substituent at 1-(1,2,3-triazolyl) and amidino moiety at C-5 position of benzimidazole ring. Specifically, compound 11f abrogated the activity of several protein kinases including TGM2, CDK9, SK1 and p38 MAPK, whereas compound 10c did not have profound effect on the activities of CDK9 and TGM2, but instead showed moderate downregulation of SK1 activity concomitant with a significant reduction in p38 MAPK. Further in silico structural analysis demonstrated that compound 11f bound slightly better to the ATP binding site of p38 MAPK compared to 10c, which correlated well with observed stronger decrement in the expression level of phospho-p38 MAPK elicited by 11f in comparison with 10c.

Prognostic and predictive biomarkers post curative intent therapy

Large-scale screening trials have demonstrated that early diagnosis of lung cancer results in a significant reduction in lung cancer mortality. Despite improvements in detecting more lung cancers at early stages, the 5-year survival rates of lung cancers diagnosed before widespread disease is only 30-50%. High rates of recurrence, despite early diagnosis, suggest the need to improve treatment strategies based on the likelihood of recurrence in patient subsets, as well as explore the role of predictive markers for therapy selection in the adjuvant setting. In the era of personalized medicine, there have been a wide array of molecular alterations and signatures studied for their potential prognostic and predictive utility, however most have failed to translate into clinical tools. This review will discuss progress made in clinical management of lung cancer, and recent progress in the development of patient selection tools for the refinement of early stage lung cancers.

Long non-coding RNAs associated with non-small cell lung cancer

Lung cancer, with 80–85% being non-small cell lung cancer (NSCLC), is the leading cause of cancer-related death in both men and women. Long non-coding RNAs (lncRNAs), always defined as non-protein-coding RNA molecules longer than 200 nucleotides, are now thought as a new frontier in the study of human malignant diseases including NSCLC. As researches continue, increasing number of roles that lncRNAs play in NSCLC has been found, and more and more evidences show lncRNAs have a close relationship with patients’ response to radiochemotherapy or molecular therapy. The aim of this review is to disclose the roles that lncRNAs play in NSCLC and how lncRANs influence the treatment of NSCLC.

Mitochondrial markers predict survival and progression in non-small cell lung cancer (NSCLC) patients: Use as companion diagnostics

Here, we used an informatics-based approach to identify novel biomarkers of overall survival and tumor progression in non-small cell lung cancer (NSCLC) patients. We determined whether nuclear-encoded genes associated with mitochondrial biogenesis and function can be used to effectively predict clinical outcome in lung cancer. This strategy allowed us to directly provide in silico validation of the prognostic value of these mitochondrial components in large, clinically-relevant, lung cancer patient populations. Towards this end, we used a group of 726 lung cancer patients, with negative surgical margins. Importantly, in this group of cancer patients, markers of cell proliferation (Ki67 and PCNA) were associated with poor overall survival, as would be expected. Similarly, key markers of inflammation (CD163 and CD68) also predicted poor clinical outcome in this patient population. Using this approach, we identified >180 new individual mitochondrial gene probes that effectively predicted significantly reduced overall survival, with hazard-ratios (HR) of up to 4.89 (p<1.0e-16). These nuclear-encoded mitochondrial genes included chaperones, membrane proteins as well as ribosomal proteins (MRPs) and components of the OXPHOS (I-V) complexes. In this analysis, HSPD1, a key marker of mitochondrial biogenesis, had the highest predictive value and was also effective in predicting tumor progression in both smokers and non-smokers alike. In fact, it had even higher predictive value in non-smokers (HR=5.9; p=3.9e-07). Based on this analysis, we conclude that mitochondrial biogenesis should be considered as a new therapeutic target, for the more effective treatment of human lung cancers. The mitochondrial biomarkers that we have identified could serve as new companion diagnostics to assist clinicians in more accurately predicting clinical outcomes in lung cancer patients, driving more personalized cancer therapy.