MutS Homologue 2 and the Long-term Benefit of Adjuvant Chemotherapy in Lung Cancer

Low tumor interleukin-1β expression predicts a limited effect of adjuvant platinum-based chemotherapy for patients with completely resected lung adenocarcinoma: An identification and validation study

INTRODUCTION AND OBJECTIVES

Adjuvant platinum-based chemotherapy for completely resected non-small cell lung cancer is associated with modest improvement in survival; nevertheless, no validated biomarker exists for predicting the benefit or harm of adjuvant platinum-based chemotherapy.

MATERIALS AND METHODS

We simultaneously measured 27 cytokines in operative tumor specimens from a discovery cohort (n = 97) by multiplex immunoassay; half of the patients received adjuvant platinum-based chemotherapy, and the other half were observed. We tested possible prognostic and predictive factors in multivariate Cox models for overall survival (OS) and relapse-free survival (RFS), and a tree-based method was applied to detect predictive factors with respect to RFS. The results were validated in an independent validation cohort (n = 93).

RESULTS

Fifty-two of 97 (54 %) patients in the discovery cohort and 50 of 93 (54 %) in the validation cohort received adjuvant chemotherapy; forty-four (85 %) patients in the discovery cohort and 37 (74 %) in the validation cohort received four cycles as planned. In patients with low IL-1β-expressing tumors, RFS and OS were worse after adjuvant chemotherapy than after observation. The limited effect of adjuvant chemotherapy for patients with low IL-1β-expressing tumors was confirmed in the validation cohort. Additionally, RFS and OS were prolonged by adjuvant chemotherapy only in patients with high IL-1β-expressing tumors in the validation cohort.

CONCLUSIONS

This study identified and validated low tumor IL-1β expression as a potential biomarker of a limited response to adjuvant platinum-based chemotherapy after complete resection of pulmonary adenocarcinoma. This finding has the potential to inform adjuvant treatment decisions.

SETD8, a frequently mutated gene in cervical cancer, enhances cisplatin sensitivity by impairing DNA repair

BACKGROUND

Cisplatin is commonly used to treat cervical cancer while drug resistance limits its effectiveness. There is an urgent need to identify strategies that increase cisplatin sensitivity and improve the outcomes of chemotherapy.

RESULTS

We performed whole exome sequencing (WES) of 156 cervical cancer tissues to assess genomic features related to platinum-based chemoresistance. By using WES, we identified a frequently mutated locus SETD8 (7%), which was associated with drug sensitivity. Cell functional assays, in vivo xenografts tumor growth experiments, and survival analysis were used to investigate the functional significance and mechanism of chemosensitization after SETD8 downregulation. Knockdown of SETD8 increased the responsiveness of cervical cancer cells to cisplatin treatment. The mechanism is exerted by reduced binding of 53BP1 to DNA breaks and inhibition of the non-homologous end joining (NHEJ) repair pathway. In addition, SETD8 expression was positively correlated with resistance to cisplatin and negatively associated with the prognosis of cervical cancer patients. Further, UNC0379 as a small molecule inhibitor of SETD8 was found to enhance cisplatin sensitivity both in vitro and in vivo.

CONCLUSIONS

SETD8 was a promising therapeutic target to ameliorate cisplatin resistance and improve the efficacy of chemotherapy.

High MutS homolog 2 expression predicts poor prognosis and is related to immune infiltration in endometrial carcinoma

Several studies have shown that MutS homolog 2 (MSH2) is highly expressed in many cancer tissues. Transcriptome expression data were collected from the Cancer Genome Atlas (TCGA) database. We analyzed the expression of MSH2 in normal and tumor tissues, the relationship between MSH2 expression and various prognostic factors, and the relationship between MSH2 expression and overall survival, disease specific survival, and progression free interval. We also examined MSH2 promoter methylation between endometrial cancer and normal endometrial tissues, and identified the prognostic value of MSH2 methylation in endometrial cancer. MSH2 was highly expressed in endometrial cancer tumor tissues compared with normal tissues. High MSH2 expression might be an independent prognostic factor for OS, DSS, and PFI. Further, high MSH2 expression was correlated with age and histological type, but not with BMI, clinical stage, tumor invasion, or other clinical features. MSH2 promoter methylation in endometrial cancer was significantly lower than in normal tissues. Additionally, MSH2 levels, OS, DSS, and PFI were associated with BMI, age, tumor invasion, and histological type. ssGSEA showed that MSH2 expression was positively correlated with the infiltration of Th2 cells, Tcm cells, T helper cells, and Tgd cells, whereas it was negatively correlated with NK CD56 bright cells, pDC cells, iDC cells, cytotoxic cells, and neutrophils. Increased MSH2 expression and reduced MSH2 methylation in endometrial cancer predicts poor prognosis. MSH2 may be used as a biomarker for the diagnosis and prognosis of endometrial cancer and as an immunotherapy target.

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.

Hsp90 inhibition sensitizes DLBCL cells to cisplatin

Purpose

Platinum-containing therapy is standard treatment for relapsed Diffuse Large B-Cell Lymphoma (DLBCL). However, the efficacy of treatment is limited by drug resistance leading to relapse. Cisplatin resistance has been linked to impairments of the DNA damage response, and several DNA repair proteins have been identified as clients of the molecular chaperone Hsp90. Here, we investigated the combinatory treatment of cisplatin and the Hsp90 inhibitor, 17AAG, in DLBCL cells to evaluate if inhibition of Hsp90 could sensitize DLBCL cells to cisplatin treatment.

Methods

Cell viability was assessed for cisplatin and 17AAG as monotherapies and for 25 different combinations in 7 DLBCL cell lines, where the Bliss Independence Model and the Combination Index were applied to assess their interaction. Induction of apoptosis and DNA damage response were evaluated by measuring Annexin V and γH2AX levels after 48 h of exposure.

Results

17AAG synergized with cisplatin in DLBCL cells as detected in both interaction assessment models, resulting in a lower viability after 48 h for the combination-treated cells compared to both vehicle and single drug-treated cells. The combination also induced a stronger apoptotic response and an increase in DNA damage in 17AAG, cisplatin- and combination-treated cells compared to vehicle-treated cells, with the effect of the combination generally being higher than compared to both single drugs.

Conclusion

This study demonstrates that 17AAG sensitizes DLBCL cells to cisplatin treatment. This effect is correlated with increased apoptotic and DNA damage response, potentially mediated by downregulation of Hsp90 clients in DNA repair pathways. Thus, cisplatin resistance could plausibly be overcome by combining the treatment with an Hsp90 inhibiting drug.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-022-04407-5.

Chemotherapy resistance in epithelial ovarian cancer: Mechanisms and emerging treatments

Ovarian cancer (OC) remains a fatal malignancy because most patients experience recurrent disease, which is resistant to chemotherapy. The outcomes for patients with platinum-resistant OC are poor, response rates to further chemotherapy are low and median survival is lower than 12 months. The complexity of platinum-resistant OC, which comprises a heterogeneous spectrum of diseases, is indeed far from being completely understood. Therefore, comprehending tumors' biological behaviour to identify reliable biomarkers, which may predict responses to therapies, is a demanding challenge to improve OC management. In the age of precision medicine, efforts to overcome platinum resistance in OC represent a dynamic and vast field in which innovative drugs and clinical trials rapidly develop. This review will present the exceptional biochemical environment implicated in OC and highlights mechanisms of chemoresistance. Furthermore, innovative molecules and new therapeutic opportunities are presented, along with currently available therapies and ongoing clinical trials.

Mitogen signal-associated pathways, energy metabolism regulation, and mediation of tumor immunogenicity play essential roles in the cellular response of malignant pleural mesotheliomas to platinum-based treatment: a retrospective study

Background

Malignant pleural mesothelioma (MPM) is a rare malignant tumor associated with asbestos exposure, with infaust prognosis and overall survival below 20 months in treated patients. Platinum is still the backbone of the chemotherapy protocols, and the reasons for the rather poor efficacy of platinum compounds in MPM remain largely unknown. Therefore, we aimed to analyze differences in key signaling pathways and biological mechanisms in therapy-naïve samples and samples after chemotherapy in order to evaluate the effect of platinum-based chemotherapy.

Methods

The study cohort comprised 24 MPM tumor specimens, 12 from therapy-naïve and 12 from patients after platinum-based therapy. Tumor samples were screened using the NanoString nCounter platform for digital gene expression analysis with an appurtenant custom-designed panel comprising a total of 366 mRNAs covering the most important tumor signaling pathways. Significant pathway associations were identified by gene set enrichment analysis using the WEB-based GEne SeT AnaLysis Toolkit (WebGestalt)

Results

We have found reduced activity of TNF (normalized enrichment score: 2.03), IL-17 (normalized enrichment score: 1.93), MAPK (normalized enrichment score: 1.51), and relaxin signaling pathways (normalized enrichment score: 1.42) in the samples obtained after platinum-based therapy. In contrast, AMPK (normalized enrichment score: –1.58), mTOR (normalized enrichment score: –1.50), Wnt (normalized enrichment score: –1.38), and longevity regulating pathway (normalized enrichment score: –1.31) showed significantly elevated expression in the same samples.

Conclusions

We could identify deregulated signaling pathways due to a directed cellular response to platinum-induced cell stress. Our results are paving the ground for a better understanding of cellular responses and escape mechanisms, carrying a high potential for improved clinical management of patients with MPM.

A Preliminary Study of NER and MMR Pathways Involved in Chemotherapy Response in Bladder Transitional Cell Carcinoma: Impact on progression-free survival

One of the main genotoxic drugs used in bladder cancer chemotherapy is cisplatin. While it is applied in most types of cancers, resistance to cisplatin is wildly common. In order to overcome drug resistance, it is necessary to determine a predictive marker. This study was conducted to provide basic data for selecting and designing a gene profile for further cohort and RCT studies in the future to improve response to treatment in bladder cancer. The expression levels of ERCC1, MLH1, MSH2, and CTR1 mRNA were determined in the tumor tissue using real-time q-PCR. Progression-free survival (PFS) was analyzed in term of the level of genes expression. The results revealed that the level of ERCC1 mRNA expression was higher in the recurrence (R) group compared to the no recurrence (NR) group. Moreover, the PFS time was increased in the patients with an ERCC1 expression level of below 1.57. The level of MLH1 and MSH2 mRNA expression was lower in the R group compared to the NR group; therefore, PFS time was increased in the patients with MLH1 and MSH2 gene expression levels above the cutoff point. While the level of CTR1 mRNA expression was higher in the R group versus the NR group, the PFS time was longer in the patients with CTR1 expression levels of below 1.265 compared to the patients with high levels of CTR1 expression. It can be concluded that the level of ERCC1, MLH1, MSH2, and CTR1 mRNA expression may be associated with PFS time as possible therapeutic targets for decreasing cisplatin resistance.

The Therapeutic Potential of DNA Damage Repair Pathways and Genomic Stability in Lung Cancer

Despite advances in our understanding of the molecular biology of the disease and improved therapeutics, lung cancer remains the most common cause of cancer-related deaths worldwide. Therefore, an unmet need remains for improved treatments, especially in advanced stage disease. Genomic instability is a universal hallmark of all cancers. Many of the most commonly prescribed chemotherapeutics, including platinum-based compounds such as cisplatin, target the characteristic genomic instability of tumors by directly damaging the DNA. Chemotherapies are designed to selectively target rapidly dividing cells, where they cause critical DNA damage and subsequent cell death (1, 2). Despite the initial efficacy of these drugs, the development of chemotherapy resistant tumors remains the primary concern for treatment of all lung cancer patients. The correct functioning of the DNA damage repair machinery is essential to ensure the maintenance of normal cycling cells. Dysregulation of these pathways promotes the accumulation of mutations which increase the potential of malignancy. Following the development of the initial malignancy, the continued disruption of the DNA repair machinery may result in the further progression of metastatic disease. Lung cancer is recognized as one of the most genomically unstable cancers (3). In this review, we present an overview of the DNA damage repair pathways and their contributions to lung cancer disease occurrence and progression. We conclude with an overview of current targeted lung cancer treatments and their evolution toward combination therapies, including chemotherapy with immunotherapies and antibody-drug conjugates and the mechanisms by which they target DNA damage repair pathways.

Gefitinib sensitization of cisplatin-resistant wild-type EGFR non-small cell lung cancer cells

Purpose

The usual first-line strategy of wild-type EGFR (wtEGFR) non-small cell lung cancer (NSCLC) remains cisplatin-based chemotherapy. However, cisplatin often loses effectiveness because most tumors acquire drug resistance over time. As EGFR is the most important pro-survival/proliferation signal receptor in NSCLC cells, we aimed at investigating whether cisplatin resistance is related to EGFR activation and further evaluating the combined effects of cisplatin/gefitinib (EGFR-tyrosine kinase inhibitor, EGFR-TKI) on cisplatin-resistant wtEGFR NSCLC cells.

Materials and methods

EGFR activation was analysed in parental and cisplatin-resistant wtEGFR NSCLC cell lines (H358 and H358^R, A549 and A549^R). Cellular proliferation and apoptosis of H358^R/A549^R cells treated with cisplatin or gefitinib, alone or in combination were investigated, and the related effector protein was detected by western blot analysis. Anti-tumor effect of two drugs combined was evaluated in animal models of H358^R xenografts in vivo.

Results

EGFR was significantly phosphorylated in cisplatin-resistant wtEGFR NSCLC cells H358^R and A549^R than their parental cells. In H358^R and A549^R cells, anti-proliferative ability of gefitinib was further improved, and gefitinib combined with cisplatin enhanced inhibition of cellular survive/proliferation, and promotion of apoptosis in vitro. The combined effects were also associated with the inhibition of EGFR downstream effector proteins. Similarly, in vivo, gefitinib and cisplatin in combination significantly inhibited tumor growth of H358^R xenografts.

Conclusion

Abnormal activation of EGFR may induce wtEGFR NSCLC cell resistance to cisplatin. The combined effects of cisplatin/gefitinib suggest that gefitinib, as a combination therapy for patients with cisplatin-resistant wtEGFR NSCLC should be considered.

The Effect of NNK, A Tobacco Smoke Carcinogen, on the miRNA and Mismatch DNA Repair Expression Profiles in Lung and Head and Neck Squamous Cancer Cells

Tobacco smoking is a common risk factor for lung cancer and head and neck cancer. Molecular changes such as deregulation of miRNA expression have been linked to tobacco smoking in both types of cancer. Dysfunction of the Mismatch DNA repair (MMR) mechanism has also been associated with a poor prognosis of these cancers, while a cross-talk between specific miRNAs and MMR genes has been previously proposed. We hypothesized that exposure of lung and head and neck squamous cancer cells (NCI and FaDu, respectively) to tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is capable of altering the expression of MSH2 and MLH1, key MMR components, by promoting specific miRNA deregulation. We found that either a low (1 μM) or high (2 μM) dose of NNK induced significant upregulation of "oncomirs" miR-21 and miR-155 and downregulation of "tumor suppressor" miR-422a, as well as the reduction of MMR protein and mRNA expression, in NCI and FaDu, compared to controls. Inhibition of miR-21 restored the NNK-induced reduced MSH2 phenotype in both NCI and FaDu, indicating that miR-21 might contribute to MSH2 regulation. Finally, NNK exposure increased NCI and FaDu survival, promoting cancer cell progression. We provide novel findings that deregulated miR-21, miR-155, and miR-422a and MMR gene expression patterns may be valuable biomarkers for lung and head and neck squamous cell cancer progression in smokers.

Screening of Pleural Mesothelioma Cell Lines for Kinase Activity May Identify New Mechanisms of Therapy Resistance in Patients Receiving Platin-Based Chemotherapy

Background

Malignant pleural mesothelioma (MPM) is a rare, predominantly asbestos-related and biologically highly aggressive tumor associated with a dismal prognosis. Multimodal therapy consisting of platinum-based chemotherapy is the treatment of choice. The reasons underlying the rather poor efficacy of platinum compounds remain largely unknown. Kinase activity might influence cellular response to these regimens.

Materials and Methods

For this exploratory study, we screened MPM cell lines (NCI-H2452, NCI-H2052, and MSTO-211H) differing in response to cisplatin and benign control fibroblasts (MRC-5) for overall phosphorylation patterns as well as kinase activity with respect to cellular response to cisplatin-based therapeutics. We analysed the cell lines for cellular kinases in a high-throughput manner using the highly innovative technique PamGene. Cell state analysis including apoptosis, necrosis, and cell viability was performed by using enzyme activity and fluorescent-based assays.

Results

Cisplatin alters cellular phosphorylation patterns affecting cell cycle, migration, adhesion, signal transduction, immune modulation, and apoptosis. In cisplatin-responsive cell lines, phosphorylation of AKT1 and GSK3B was decreased but could not be influenced in cisplatin-resistant NCI-H2452 cells. Cisplatin-responsive cell lines showed increased phosphorylation levels of JNK1/2/3 but decreased phosphorylation in cisplatin-resistant NCI-H2452 cells.

Conclusion

Kinase phosphorylation and activity might play a crucial role in cellular response to cytostatic agents. Cisplatin influences phosphorylation patterns with distinct features in cisplatin-resistant cells. These alterations exert a significant impact on cell cycle, migration, adhesion, signal transduction, immune modulation, and apoptosis of the respective tumor cells. Based on our results, the induction of p38 or JNK1/3, or inhibition of AKT1 by, for example, BIA-6, might offer a positive synergistic effect by induction of an apoptotic response to cisplatin-based treatment, thus potentially enhancing the clinical outcome of MPM patients.

Phytochemicals: Current strategy to sensitize cancer cells to cisplatin

Cisplatin-based chemotherapeutic regimens are the most frequently used adjuvant treatments for many types of cancer. However, the development of chemoresistance to cisplatin results in treatment failure. Despite the significant developments in understanding the mechanisms of cisplatin resistance, effective strategies to enhance the chemosensitivity of cisplatin are lacking. Phytochemicals are naturally occurring plant-based compounds that can augment the anti-cancer activity of cisplatin, with minimal side effects. Notably, some novel phytochemicals, such as curcumin, not only increase the efficacy of cisplatin but also decrease toxicity induced by cisplatin. However, the exact mechanisms underlying this process remain unclear. In this review, we discussed the progress made in utilizing phytochemicals to enhance the anti-cancer efficacy of cisplatin. We also presented some ideal phytochemicals as novel agents for counteracting cisplatin-induced organ damage.

Association and clinical implication of the USP10 and MSH2 proteins in non-small cell lung cancer

Ubiquitin-specific protease 10 (USP10) is involved in a number of biological processes by stabilizing several proteins, which have been implicated in multiple stages of tumorigenesis and progression. Previous studies have indicated that USP10 stabilizes and deubiquitinates MutS homolog 2 (MSH2) in in vitro and in vivo models. The level of MSH2 protein has been positively correlated with that of the USP10 protein in a panel of lung cancer cell lines. Furthermore, depletion of USP10 in lung cancer cells causes decreased apoptosis and increased cell survival upon treatment with DNA-damaging agents. However, the expression and clinical implication of USP10 protein in lung cancer tissues is not clear. Additionally, whether the level of MSH2 protein is positively correlated with that of the USP10 protein in lung cancer tissues also remains unresolved. Therefore, USP10 protein expression was detected in 148 human non-small cell lung cancer (NSCLC) and 139 non-cancerous lung tissues using immunohistochemistry, whereas mRNA was investigated by Gene Expression Omnibus dataset and The Cancer Genome Atlas database analyses. It was identified that USP10 protein expression was significantly downregulated in NSCLC tissues compared with in normal lung tissues (P<0.05). However, no significant difference in USP10 mRNA expression between the two tissues was identified. In addition, a positive correlation was observed between the USP10 and MSH2 proteins in NSCLC tissues (P<0.05). However, the clinicopathological features and survival analysis indicated that the USP10 and MSH2 proteins were not associated with clinical features, including age, sex, tumor size, Tumor-Node-Metastasis stage and tumor cell differentiation, along with the prognosis of NSCLC. Collectively, these results suggest that downregulation of USP10 protein serves an important function in the tumorigenesis of NSCLC, and the level of USP10 protein is positively correlated with that of MSH2 protein in NSCLC tissues, which may indicate that USP10 also stabilizes the MSH2 protein in patients with lung cancer.

A Whole-genome CRISPR Screen Identifies a Role of MSH2 in Cisplatin-mediated Cell Death in Muscle-invasive Bladder Cancer

BACKGROUND

The response to first-line, platinum-based treatment of muscle-invasive bladder cancer has not improved in 3 decades.

OBJECTIVE

To identify genes that influence cisplatin resistance in bladder cancer.

DESIGN, SETTING, AND PARTICIPANTS

We performed a whole-genome CRISPR screen in a bladder cancer cell line to identify genes that mediate resistance to cisplatin.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Targeted validation was performed in two bladder cancer cell lines. The top gene candidate was validated in a publicly available bladder cancer dataset.

RESULTS AND LIMITATIONS

From the CRISPR screen, we identified MSH2 as the most significantly enriched gene and mismatch repair as the most significantly enriched pathway that promoted resistance to cisplatin. Bladder cancer cells with knockdown of MSH2 showed a reduction in cisplatin-mediated apoptosis. MSH2 loss did not impact the sensitivity to other chemotherapies, including the cisplatin analog oxaliplatin. Bladder tumors with low MSH2 protein levels, quantified using reverse-phase protein array, showed poorer survival when treated with cisplatin- or carboplatin-based therapy; these results require future validation using immunohistochemistry. Additionally, results are retrospective from patients with primarily high-grade tumors; thus, validation in a controlled clinical trial is needed.

CONCLUSIONS

We generated in vitro evidence that bladder cancer cell lines depleted of MSH2 are more resistant to cisplatin. We additionally found an association between low MSH2 in bladder tumors and poorer patient survival when treated with platinum-based chemotherapy. If successfully validated prospectively, MSH2 protein level could assist in the selection of patients for chemotherapy.

PATIENT SUMMARY

We report the first evidence that MSH2 protein level may contribute to chemotherapy resistance observed in muscle-invasive bladder cancer. MSH2 has potential as a biomarker predictive of response to platinum-based therapy.

DNA repair pathways and cisplatin resistance: an intimate relationship

The main goal of chemotherapeutic drugs is to induce massive cell death in tumors. Cisplatin is an antitumor drug widely used to treat several types of cancer. Despite its remarkable efficiency, most tumors show intrinsic or acquired drug resistance. The primary biological target of cisplatin is genomic DNA, and it causes a plethora of DNA lesions that block transcription and replication. These cisplatin-induced DNA lesions strongly induce cell death if they are not properly repaired or processed. To counteract cisplatin-induced DNA damage, cells use an intricate network of mechanisms, including DNA damage repair and translesion synthesis. In this review, we describe how cisplatin-induced DNA lesions are repaired or tolerated by cells and focus on the pivotal role of DNA repair and tolerance mechanisms in tumor resistance to cisplatin. In fact, several recent clinical findings have correlated the tumor cell status of DNA repair/translesion synthesis with patient response to cisplatin treatment. Furthermore, these mechanisms provide interesting targets for pharmacological modulation that can increase the efficiency of cisplatin chemotherapy.

Inhibition of MDM2 via Nutlin-3A: A Potential Therapeutic Approach for Pleural Mesotheliomas with MDM2-Induced Inactivation of Wild-Type P53

Previously, our group demonstrated that nuclear expression of E3 ubiquitin ligase (MDM2) in malignant pleural mesothelioma (MPM) is significantly associated with decreased overall survival. A possible explanation may be that overexpression of MDM2 leads to a proteasomal degradation of TP53 that eventually results in a loss of TP53-induced apoptosis and senescence. It is well known from other tumor entities that restoration of TP53 activity, e.g., by MDM2 inhibition, results in an instant TP53-induced stress and/or DNA damage response of cancer cells. Nutlin-3A (a cis-imidazoline analogue) has been described as a potent and selective MDM2 inhibitor preventing MDM2-TP53-interaction by specific binding to the hydrophobic TP53-binding pocket of MDM2. In the present study, the effects of MDM2 inhibition in MPM via Nutlin-3A and standard platinum based chemotherapeutic agents were comparatively tested in three MPM cell lines (NCI-H2052, MSTO-211H, and NCI-H2452) showing different expression profiles of TP53, MDM2, and its physiological inhibitor of MDM2—P14/ARF. Our in vitro experiments on MPM cell lines revealed that Nutlin-3A in combination with cisplatin resulted in up to 9.75 times higher induction of senescence (p=0.0050) and up to 5 times higher apoptosis rate (p=0.0067) compared to the commonly applied cisplatin and pemetrexed regimens. Thus Nutlin-3A, a potent inhibitor of MDM2, is associated with a significant induction of senescence and apoptosis in MPM cell lines, making Nutlin-3A a promising substance for a targeted therapy in the subgroup of MPM showing MDM2 overexpression.

Differential Proteomic Analysis between Small Cell Lung Carcinoma (SCLC) and Pulmonary Carcinoid Tumors Reveals Molecular Signatures for Malignancy in Lung Cancer

PURPOSE

The molecular underpinnings that may prognosticate survival and increase our understanding of tumor development and progression are still poorly understood. This study aimed to define the molecular signatures for malignancy in small cell lung carcinoma (SCLC), which is known for its highly aggressive clinical features and poor prognosis.

EXPERIMENTAL DESIGN

Using clinical specimens, the authors perform a comparative proteomic analysis of high-grade SCLCs and low-grade pulmonary carcinoid tumors (PCTs), both of which are types of neuroendocrine tumors. A label-free LC-MS-based quantitative proteomic analysis is applied to tumor cells laser-microdissected from their formalin-fixed paraffin-embedded (FFPE) tissues obtained from six patients each.

RESULTS

Overall, 1991 proteins are identified from tumor cells in the FFPE tissues. Through the protein-protein interaction network analysis of 201 proteins significantly, the authors find that SCLC is functionally characterized by activation of molecular pathways for spliceosome, RNA transport, and DNA replication and cell cycle. Particularly, 11 proteins involved in tumor proliferation (MCM2, 4, 6, 7, and MSH2), metastasis (RCC2, CORO1C, CHD4, and IPO9), and cancer metabolism (PHGDH and TYMP) are identified as SCLC-specific proteins. Furthermore, their prognostic significances are demonstrated by online Kaplan-Meier survival analysis.

CONCLUSIONS AND CLINICAL RELEVANCE

These clinical tissue proteomic approach for SCLC reveals the proteins associated with aggressiveness and poor prognosis. The identified SCLC-specific proteins represent potential therapeutic targets. Moreover, MCMs and PHGDH can be poor prognostic factors for lung cancer.

Immunohistochemically detectable metallothionein expression in malignant pleural mesotheliomas is strongly associated with early failure to platin-based chemotherapy

Background

Malignant pleural mesothelioma (MPM) is a biologically highly aggressive tumor arising from the pleura with a dismal prognosis. Cisplatin is the drug of choice for the treatment of MPM, and carboplatin seems to have comparable efficacy. Nevertheless, cisplatin treatment results in a response rate of merely 14% and a median survival of less than seven months. Due to their role in many cellular processes, methallothioneins (MTs) have been widely studied in various cancers. The known heavy metal detoxifying effect of MT-I and MT-II may be the reason for heavy metal drug resistance of various cancers including MPM.

Methods

105 patients were retrospectively analyzed immunohistochemically for their MT expression levels. Survival analysis was done by Cox-regression, and statistical significance determined using likelihood ratio, Wald test and Score (logrank) tests.

Results

Cox-regression analyses were done in a linear and logarithmic scale revealing a significant association between expression of MT and shortened overall survival (OS) in a linear (p=0.0009) and logarithmic scale (p=0.0003). Reduced progression free survival (PFS) was also observed for MT expressing tumors (linear: p=0.0134, log: p=0.0152).

Conclusion

Since both, overall survival and progression-free survival are negatively correlated with detectable MT expression in MPM, our results indicate a possible resistance to platin-based chemotherapy associated with MT expression upregulation, found exclusively in progressive MPM samples. Initial cell culture studies suggest promoter DNA hypomethylation and expression of miRNA-566 a direct regulator of copper transporter SLC31A1 and a putative regulator of MT1A and MT2A gene expression, to be responsible for the drug resistance.

Molecular prediction of adjuvant cisplatin efficacy in Non-Small Cell Lung Cancer (NSCLC)-validation in two independent cohorts

INTRODUCTION

Effective predictive biomarkers for selection of patients benefiting from adjuvant platinum-based chemotherapy in non-small cell lung cancer (NSCLC) are needed. Based on a previously validated methodology, molecular profiles of predicted sensitivity in two patient cohorts are presented.

METHODS

The profiles are correlations between in vitro sensitivity to cisplatin and vinorelbine and baseline mRNA expression of the 60 cell lines in the National Cancer Institute panel. An applied clinical samples filter focused the profiles to clinically relevant genes. The profiles were tested on 1) snap-frozen tumors from 133 patients with completely resected stage 1B-2 NSCLC randomized to adjuvant cisplatin and vinorelbine (ACV, n = 71) or no adjuvant treatment (OBS, n = 62) and 2) formalin-fixed paraffin-embedded (FFPE) tumors from 95 patients with completely resected stage 1A-3B NSCLC receiving adjuvant cisplatin and vinorelbine.

RESULTS

The combined cisplatin and vinorelbine profiles showed: 1) univariate Hazard Ratio (HR) for sensitive versus resistant of 0.265 (95% CI:0.079-0.889, p = 0.032) in the ACV cohort and a HR of 0.28 in a multivariate model (95% CI:0.08-1.04, p = 0.0573); 2) significant prediction at 3 year survival from surgery in univariate (HR = 0.138 (95% CI:0.035-0.537), p = 0.004) and multivariate analysis (HR = 0.14 (95% CI:0.030-0.6), p = 0.0081). No discrimination was found in the OBS cohort (HR = 1.328, p = 0.60). The cisplatin predictor alone had similar figures with 1) univariate HR of 0.37 (95% CI:0.12-1.15, p = 0.09) in the ACV cohort and 2) univariate HR of 0.14 (95% CI:0.03-0.59, p = 0.0076) to three years. Functional analysis on the cisplatin profile revealed a group of upregulated genes related to RNA splicing as a part of DNA damage repair and apoptosis.

CONCLUSIONS

Profiles derived from snap-frozen and FFPE NSCLC tissue were prognostic and predictive in the patients that received cisplatin and vinorelbine but not in the cohort that did not receive adjuvant treatment.

The combination of the blood based tumor biomarkers cytokeratin 19 fragments (CYFRA 21-1) and carcinoembryonic antigen (CEA) as a potential predictor of benefit from adjuvant chemotherapy in early stage squamous cell carcinoma of the lung (SCC)

OBJECTIVES

To determine whether the tumor biomarkers cytokeratin 19 fragment (CYFRA 21-1) and carcinoembryonic antigen (CEA), which are prognostic in early-stage non-small cell lung cancer (NSCLC), can predict which patients benefit from adjuvant chemotherapy (CTx).

MATERIALS AND METHODS

Serum samples were collected preoperatively from patients with NSCLC who underwent resection. Samples were retrospectively analyzed for CYFRA 21-1 and CEA via electrochemiluminescence immunoassay. Recurrence-free survival (RFS) was compared for patients who received adjuvant CTx versus surgery alone, stratified based on the following prognostic classifications: (1) tumor stage (pT1-2/N0 [stage I] or pT3/N0 or pT1-2/N1 [stage II]), (2) biomarker-based risk score, (3) clinical characteristics. Absolute 2-year RFS rates were calculated via Kaplan-Meier estimations; statistical significance level: 0.05.

RESULTS

227 patients were included (stage I: 69%; male: 67%; median age 65 years); 70 received adjuvant CTx. Median duration of sample collection was 58.8 months. All high-risk patients (by all three prognostic classifications) who received adjuvant CTx had a longer RFS versus those who received surgery alone. In patients with squamous cell carcinoma (SCC) classified as high risk by all three prognostic classifications, there was a benefit from adjuvant CTx versus surgery alone (tumor stage hazard ratio [HR] 4.9, p = 0.004; biomarker levels HR 9.4, p = 0.002; clinical characteristics HR 9.0, p = 0.003). None of the prognostic classifications were able to predict a benefit from adjuvant CTx in patients with adenocarcinoma.

CONCLUSION

Baseline CYFRA 21-1 and CEA levels may provide further information to help clinicians decide which patients with SCC should receive adjuvant CTx. Further evaluation of these biomarkers is warranted.

MSH2/BRCA1 expression as a DNA-repair signature predicting survival in early-stage lung cancer patients from the IFCT-0002 Phase 3 Trial

Introduction

DNA repair is a double-edged sword in lung carcinogenesis. When defective, it promotes genetic instability and accumulated genetic alterations. Conversely these defects could sensitize cancer cells to therapeutic agents inducing DNA breaks.

Methods

We used immunohistochemistry (IHC) to assess MSH2, XRCC5, and BRCA1 expression in 443 post-chemotherapy specimens from patients randomized in a Phase 3 trial, comparing two neoadjuvant regimens in 528 Stage I-II non-small cell lung cancer (NSCLC) patients (IFCT-0002). O6MGMT promoter gene methylation was analyzed in a subset of 208 patients of the same trial with available snap-frozen specimens.

Results

Median follow-up was from 90 months onwards. Only high BRCA1 (n = 221, hazard ratio [HR] = 1.58, 95% confidence interval [CI] [1.07-2.34], p = 0.02) and low MSH2 expression (n = 356, HR = 1.52, 95% CI [1.11-2.08], p = 0.008) significantly predicted better overall survival (OS) in univariate and multivariate analysis. A bootstrap re-sampling strategy distinguished three patient groups at high (n = 55, low BRCA1 and high MSH2, median OS >96 months, HR = 2.5, 95% CI [1.45-4.33], p = 0.001), intermediate (n = 82, median OS = 73.4 p = 0.0596), and low (high BRCA1 and low MSH2, n = 67, median OS = ND, HR = 0.51, 95% CI [0.31-0.83], p = 0.006) risk of death.

Interpretation

DNA repair protein expression assessment identified three different groups of risk of death in early-stage lung cancer patients, according to their tumor MSH2 and BRCA1 expression levels. These results deserve prospective evaluation of MSH2/BRCA1 theranostic value in lung cancer patients treated with combinations of DNA-damaging chemotherapy and drugs targeting DNA repair, such as Poly(ADP-ribose) polymerase (PARP) inhibitors.

Folic-acid metabolism and DNA-repair phenotypes differ between neuroendocrine lung tumors and associate with aggressive subtypes, therapy resistance and outcome

Purpose

25% of all lung cancer cases are neuroendocrine (NELC) including typical (TC) and atypical carcinoid (AC), large-cell neuroendocrine (LCNEC) and small cell lung cancer (SCLC). Prognostic and predictive biomarkers are lacking.

Experimental Design

Sixty patients were used for nCounter mRNA expression analysis of the folic-acid metabolism (ATIC, DHFR, FOLR1, FPGS, GART, GGT1, SLC19A1, TYMS) and DNA-repair (ERCC1, MLH1, MSH2, MSH6, XRCC1). Phenotypic classification classified tumors (either below or above the median expression level) with respect to the folic acid metabolism or DNA repair.

Results

Expression of FOLR1, FPGS, MLH1 and TYMS (each p<0.0001) differed significantly between all four tumor types. FOLR1 and FPGS associated with tumor differentiation (both p<0.0001), spread to regional lymph nodes (FOLR1 p=0.0001 and FPGS p=0.0038), OS and PFS (FOLR1 p<0.0050 for both and FPGS p<0.0004 for OS).

Phenotypic sorting revealed the Ft-phenotype to be the most prominent expression profile in carcinoids, whereas SCLC presented nearly univocal with the fT and LCNEC with fT or ft. These results were significant for tumor subtype (p<0.0001).

Conclusions

The assessed biomarkers and phenotypes allow for risk stratification (OS, PFS), diagnostic classification and enhance the biological understanding of the different subtypes of neuroendocrine tumors revealing potential new therapy options and clarifying known resistance mechanisms.

[Current knowledge on perioperative treatments of non-small cell lung carcinomas]

Surgery is still the main treatment in early-stage of non-small cell lung cancer with 5-year survival of stage IA patients exceeding 80%, but 5-year survival of stage II patients rapidly decreasing with tumor size, N status, and visceral pleura invasion. The major metastatic risk in such patients has supported clinical research assessing systemic or loco-regional perioperative treatments. Modern phase 3 trials clearly validated adjuvant or neo-adjuvant platinum-based chemotherapy in resected stage I-III patients as a standard treatment of which value has been reassessed several independent meta-analyses, showing a 5% benefit in 5y-survival, and a decrease of the relative risk for death around from 12 to 25%. Conversely perioperative treatments were not validated for stage IA and IB patients. In more advanced stage patients, neo-adjuvant radio-chemotherapy has not been validated either. Adjuvant radiotherapy for N2 patients is currently tested in the large international phase 3 trial Lung-ART/IFCT-0503. The development of video-assisted thoracic surgery (VATS) has helped adjuvant chemotherapies for elderly patients. Perioperative targeted treatments in NSCLC with EGFR or ALK molecular alterations is currently assessed in the U.S. ALCHEMIST prospective trial. Finally, the role of immune check-points inhibitors is currently evaluated in a large international phase 3 trial testing adjuvant anti-PD-L1 monoclonal antibody, the BR31/IFCT-1401 trial, while a proof-of principle neo-adjuvant trial IONESCO/IFCT-1601, has just begun by the end of the 2016 year, with survival results of both trials expected in 5 to 7 years.

miRNA regulation is important for DNA damage repair and recognition in malignant pleural mesothelioma

Platin-containing regimes are currently considered as state-of-the-art therapies in malignant pleural mesotheliomas (MPM) but show dissatisfying response rates ranging from 6 to 16% only. Still, the reasons for the rather poor efficacy remain largely unknown. A clear stratification of patients based on new biomarkers seems to be a promising approach to enhance clinical management, which would be a long-needed improvement for MPM patients but does not seem likely soon unless new biomarkers can be validated. Twenty-four formalin-fixed, paraffin-embedded (FFPE) tumour specimens were subjected to a miRNA expression screening of 800 important miRNAs using digital quantification via the nCounter technique (NanoString). We defined a small subset of miRNAs regulating the key enzymes involved in the repair of platin-associated DNA damage. Particularly, the TP53 pathway network for DNA damage recognition as well as genes related to the term "BRCAness" are the main miRNA targets within this context. The TP53 pathway network for DNA damage recognition as well as genes related to the term "BRCAness" are the main players for risk stratification in patients suffering from this severe disease. Taking the specific molecular profile of the tumour into account can help to enhance the clinical management prospectively and to smooth the way to better response prediction.

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

Drug therapy for non-small cell lung cancer consists mainly of platinum-based chemotherapy regimens. However, toxicity, drug resistance, and high risk of death have been seen in the clinic, which means there is a need for optimizing the use of medications. Platinum resistance could be mediated by a series of DNA repair pathways, and therefore, these pathways should be taken into account for optimizing drug using. The goal of pharmacogenomics is to elucidate genetic factors, such as DNA repair genes, which might underlie drug efficacy and effectiveness, and to improve therapeutic effects or guide personalized therapy as well. Here, we reviewed the current knowledge of pharmacogenomic data on DNA repair systems and examined whether they could be further translated into the clinic with evidence-based perspectives.

[50th anniversary of cisplatin]

We have just celebrated the 50th anniversary of cisplatin cytotoxic potential discovery. It is time to take stock… and it seems mainly positive. This drug, that revolutionized the treatment of many cancer types, continues to be the most widely prescribed chemotherapy. Despite significant toxicities, resistance mechanisms associated with treatment failures, and unresolved questions about its mechanism of action, the use of this cytotoxic agent remains unwavering. The interest concerning this "old" invincible drug has not yet abated. Indeed many research axes are in the news. New platinum salts agents are tested, new cisplatin formulations are developed to target tumor cells more efficiently, and new combinations are established to increase the cytotoxic potency of cisplatin or overcome the resistance mechanisms.

[Perioperative therapies in surgical non N2 non-small cell lung cancer]

Platinum-based perioperative chemotherapy is actually the standard of care in stage II-IIIa non-small cell lung cancer (NSCLC). A benefit may also be seen in stage IB NSCLC with tumors of more than 4cm of diameter. Perioperative chemotherapy improves 5-year survival of 4 to 15%. This benefit is mainly proved by postoperative chemotherapy trials. Nevertheless, preoperative chemotherapy has advantages: a better tolerance, an estimation of tumor chemosensibility, without an increased postoperative morbimortality. However, pTNM and pathological tumor analyses are modified. Indications of postoperative radiotherapy are limited. In early stage NSCLC (stage I-II), radiotherapy worsens survival. Radiotherapy is routinely achieved in NSCLC with parietal tumor invasion and incomplete tumor resection. Indications of immunotherapy and targeted therapies in case of oncogenic addiction remain to be established in resected NSCLC. Several biomarkers are studied to better describe the indications of perioperative chemotherapy: recognize groups of patients with a worse prognosis and distinguish chemosensibility of the tumor.

Screening of Pleural Mesotheliomas for DNA-damage Repair Players by Digital Gene Expression Analysis Can Enhance Clinical Management of Patients Receiving Platin-Based Chemotherapy

Background: Malignant pleural mesothelioma (MPM) is a rare, predominantly asbestos-related and biologically highly aggressive tumour leading to a dismal prognosis. Multimodality therapy consisting of platinum-based chemotherapy is the treatment of choice. The reasons for the rather poor efficacy of platinum compounds remain largely unknown.

Material and Methods: For this exploratory mRNA study, 24 FFPE tumour specimens were screened by digital gene expression analysis. Based on data from preliminary experiments and recent literature, a total of 366 mRNAs were investigated using a Custom CodeSet from NanoString. All statistical analyses were calculated with the R i386 statistical programming environment.

Results: CDC25A and PARP1 gene expression were correlated with lymph node spread, BRCA1 and TP73 expression levels with higher IMIG stage. NTHL1 and XRCC3 expression was associated with TNM stage. CHECK1 as well as XRCC2 expression levels were correlated with tumour progression in the overall cohort of patients. CDKN2A and MLH1 gene expression influenced overall survival in this collective. In the adjuvant treated cohort only, CDKN2A, CHEK1 as well as ERCC1 were significantly associated with overall survival. Furthermore, TP73 expression was associated with progression in this subgroup.

Conclusion: DNA-damage response plays a crucial role in response to platin-based chemotherapeutic regimes. In particular, CHEK1, XRCC2 and TP73 are strongly associated with tumour progression. ERCC1, MLH1, CDKN2A and most promising CHEK1 are prognostic markers for OS in MPM. TP73, CDKN2A, CHEK1 and ERCC1 seem to be also predictive markers in adjuvant treated MPMs. After a prospective validation, these markers may improve clinical and pathological practice, finally leading to a patients' benefit by an enhanced clinical management.

A Comprehensive Review on the Genetic Regulation of Cisplatin-induced Nephrotoxicity

Cisplatin (CDDP) is a well-known antineoplastic drug which has been extensively utilized over the last decades in the treatment of numerous kinds of tumors. However, CDDP induces a wide range of toxicities in a dose-dependent manner, among which nephrotoxicity is of particular importance. Still, the mechanism of CDDP-induced renal damage is not completely understood; moreover, the knowledge about the role of microRNAs (miRNAs) in the nephrotoxic response is still unknown. miRNAs are known to interact with the representative members of a diverse range of regulatory pathways (including postnatal development, proliferation, inflammation and fibrosis) and pathological conditions, including kidney diseases: polycystic kidney diseases (PKDs), diabetic nephropathy (DN), kidney cancer, and drug-induced kidney injury. In this review, we shed light on the following important aspects: (i) information on genes/proteins and their interactions with previously known pathways engaged with CDDP-induced nephrotoxicity, (ii) information on newly discovered biomarkers, especially, miRNAs for detecting CDDP-induced nephrotoxicity and (iii) information to improve our understanding on CDDP. This information will not only help the researchers belonging to nephrotoxicity field, but also supply an indisputable help for oncologists to better understand and manage the side effects induced by CDDP during cancer treatment. Moreover, we provide up-to-date information about different in vivo and in vitro models that have been utilized over the last decades to study CDDP-induced renal injury. Taken together, this review offers a comprehensive network on genes, miRNAs, pathways and animal models which will serve as a useful resource to understand the molecular mechanism of CDDP-induced nephrotoxicity.

Biomarkers for efficacy of adjuvant chemotherapy following complete resection in NSCLC stages I-IIIA

Biomarkers may be useful when deciding which nonsmall cell lung cancer (NSCLC) patients may benefit from adjuvant chemotherapy following complete resection and which chemotherapeutic agents may be used preferably in individual patients in order to maximise survival.

A literature search covering the period from 2003 to May, 2014 was conducted using PubMed and the following search terms: “non-small cell lung cancer”, “NSCLC”, “adjuvant chemotherapy”, “randomized”, “randomised”, “biomarkers”, “prognostic”, “predictive”. This review focuses on current knowledge of biomarkers for prognosis or efficacy of adjuvant treatment following complete resection in stage I–IIIA NSCLC patients.

This review includes results on 18 different biomarkers and five gene profiles. A statistically significant prognostic impact was reported for: iNTR, TUBB3, RRM1, ERCC1, BRCA1, p53, MRP2, MSH2, TS, mucin, BAG-1, pERK1/2, pAkt-1, microRNA, TopIIA, 15-gene profile, 92-gene profile, 31-gene profile and 14-gene profile. A statistically significant predictive impact was reported for: ERCC1, p53, MSH2, p27, TUBB3, PARP1, ATM, 37-gene profile, 31-gene profile, 15-gene profile and 92-gene profile.

Uncertainties regarding the optimal analysis method and cut-off levels for the individual markers may blur the prognostic or predictive signals. None of the possible predictive markers have been validated in prospective trials. Thus, there are no biomarkers ready to use in an adjuvant setting in NSCLC.

Further investigation and validation is required to explore biomarkers in completely resected NSCLC stage I–IIIAhttp://ow.ly/M0leE

Cancer stem cells in drug resistant lung cancer: Targeting cell surface markers and signaling pathways

Lung cancer is the leading cause of cancer mortality worldwide. Despite advances in anti-cancer therapies such as chemotherapy, radiotherapy and targeted therapies, five-year survival rates remain poor (<15%). Inherent and acquired resistance has been identified as a key factor in reducing the efficacy of current cytotoxic therapies in the management of non-small cell lung cancer (NSCLC). There is growing evidence suggesting that cancer stem cells (CSCs) play a critical role in tumor progression, metastasis and drug resistance. Similar to normal tissue stem cells, CSCs exhibit significant phenotypic and functional heterogeneity. While CSCs have been reported in a wide spectrum of human tumors, the biology of CSCs in NSCLC remain elusive. Current anti-cancer therapies fail to eradicate CSC clones and instead, favor the expansion of the CSC pool and select for resistant CSC clones thereby resulting in treatment resistance and subsequent relapse in these patients. The identification of CSC-specific marker subsets and the targeted therapeutic destruction of CSCs remains a significant challenge. Strategies aimed at efficient targeting of CSCs are becoming increasingly important for monitoring the progress of cancer therapy and for evaluating new therapeutic approaches. This review focuses on the current knowledge of cancer stem cell markers in treatment-resistant lung cancer cells and the signaling cascades activated by these cells to maintain their stem-like properties. Recent progress in CSC-targeted drug development and the current status of novel agents in clinical trials are also reviewed.

Erlotinib versus carboplatin and paclitaxel in advanced lepidic adenocarcinoma: IFCT-0504

The IFCT-0504 phase II trial evaluated the efficacy of erlotinib versus carboplatin-paclitaxel (CP) as first-line treatment in 130 cases of advanced lepidic-predominant adenocarcinoma (ADC).The primary objective of the study was treatment efficacy, evaluated based on an end-point of disease control at 16 weeks.The primary objective was met, with a disease control in 35 (53%) out of 66 patients treated with CP and in 25 (39.1%) out of 64 patients treated with erlotinib. Median progression-free survival (PFS) for the total population was 3.6 months. The disease control rate did not differ between either the therapeutic arms or pathological subtypes, whereas there was a strong interaction between treatment arms and tumour pathological subtypes for PFS (p=0.009). Mucinous tumour patients treated with erlotinib exhibited an increased progression risk (hazard ratio 3.4, 95% CI 1.7-6.5; p≤0.001). The PFS for nonmucinous tumour patients was similar in both arms. Median overall survival was 20.1 months and did not differ between therapeutic arms. These findings were not further elucidated by molecular analyses and the toxicity profiles were as expected.Our study demonstrated the dominant role of CP alongside erlotinib in the management of advanced lepidic ADC. Based on these findings, erlotinib should not be administered in first-line therapy to patients with lepidic ADC in the absence of an epidermal growth factor receptor mutation.

Prognostic and predictive biomarkers in early stage non-small cell lung cancer: tumor based approaches including gene signatures

In early stage non-small cell lung cancer (NSCLC) large randomized trials have demonstrated that in patients with radically resected disease adjuvant chemotherapy improves 5-year survival rates. However, a customization of systemic treatment is needed to avoid treatments in patients cured by surgery alone or to justify the use of adjuvant chemotherapy in high risk patients, including those in stage IA. Recently, the possibility of identifying prognostic and predictive factors related to the genetic signatures of the tumor that could affect adjuvant and neo-adjuvant treatment choices for resectable non-small cell lung cancer (NSCLC) has been of interest. This review summarizes the current status and future opportunities for clinical application of genotyping and genomic tests in early NSCLC.

Are we ready to use biomarkers for staging, prognosis and treatment selection in early-stage non-small-cell lung cancer?

Lung cancer accounts for the majority of cancer-related deaths worldwide. At present, platinum-based therapy represents the standard of care in fit stage II and IIIA non-small cell lung cancer (NSCLC) patients following surgical resection. In advanced disease, personalized chemotherapy and targeted biologic therapy based on histological and molecular tumor profiling have already shown promise in terms of optimizing treatment efficacy. While disease stage is associated with outcome and is commonly used to determine adjuvant treatment eligibility, it is known that a subset of patients with early stage disease experience shorter survival than others with the same clinicopathological characteristics. Improved methods for identifying these individuals, at or near the time of initial diagnosis, may inform the decision to pursue adjuvant therapy options. Among the numerous candidate molecular biomarkers, only few gene-expression profiling signatures provide clinically relevant information, while real-time quantitative polymerase-chain reaction (RT-qPCR) strategy involving relatively small numbers of genes offers a practical alternative with high cross-platform performance. mRNA and/or protein expression levels of excision repair cross-complementation group 1 (ERCC1), ribonucleotide reductase M subunit 1 (RRM1) and breast cancer susceptibility gene 1 (BRCA1) are among the most promising potential biomarkers for early disease and their clinical utility is currently being evaluated in randomized phase II and III clinical trials. This review describes the most promising clinicopathological and molecular biomarkers with predictive and prognostic significance in lung cancer that have been identified through advanced research and which could influence adjuvant and neoadjuvant chemotherapy decisions for operable NSCLC in routine clinical practice.

Serpin b3 is associated with poor survival after chemotherapy and is a potential novel predictive biomarker in advanced non-small-cell lung cancer

INTRODUCTION

In a previous biomarker discovery project using gene-expression profiling we identified Serpin B3 (SB3) as a predictor of resistance to platinum doublet chemotherapy (PtC) in non-small-cell lung cancer (NSCLC). This independent prospective study was designed to confirm the predictive utility of SB3.

METHODS

SB3 immunohistochemistry was scored by previously validated criteria (score 0 = negative, score 1 = 1%-10% tumor cells positive, score 2 = 11%-50% tumor cells positive, and score 3 = >50% tumor cell positive) in 197 patients with stage IV NSCLC treated with PtC. This provided 80% power to detect a median survival increase from 150 days in patients with an SB3 immunohistochemistry score of 2 or more to 300 days in those with an SB3 score of 0 or 1.

RESULTS

Thirty-six percent of NSCLCs stained positive for SB3. Median survival for SB3 negative/score 0 was 332 days, SB3 positive/score 1 was 268 days, and SB3 positive/score 2 or 3 was 120 days (p = 0.004). Cox proportional hazards analysis demonstrated that SB3 positivity is an independent predictor of survival (hazard ratio = 1.87; 95% confidence interval, 1.29-2.71; p = 0.001).The disease control rate in SB3 score 0, 1 = 65%, and score of 2 or more = 20 % (p = 0.002), with median survival 306 days (score 0, 1) versus 120 days (score ≥ 2, hazard ratio= 1.71; 95% confidence interval. 1.14-3.10; p = 0.002).

CONCLUSIONS

SB3-positive immunohistochemistry score of 2 or more (>10% tumor cells positive) identifies a subgroup of patients with stage IV NSCLC who have a poor survival (median 120 days) when treated with PtC, similar to that estimated for untreated or chemo-refractory stage IV NSCLC. Further prospective qualification using biospecimens from randomized studies is needed, but SB3 seems to be a useful biomarker that identifies a highly resistant subgroup in whom PtC should be avoided.

Expression of ERCC1, MSH2 and PARP1 in non-small cell lung cancer and prognostic value in patients treated with platinum-based chemotherapy

PURPOSE

To evaluate the prognostic value of the expression of excision repair cross-complementation group l (ERCC1), MutS protein homolog 2 (MSH2) and poly ADP-ribose polymerase 1 (PARP1) in non-small-cell lung cancer patients receiving platinum-based postoperative adjuvant chemotherapy.

METHODS

Immunohistochemistry was applied to detect the expression of ERCC1, MSH2 and PARP1 in 111 cases of non-small cell lung cancer paraffin embedded surgical specimens. Through og-rank survival analysis, we evaluated the prognostic value of the ERCC1, MSH2, PARP1 and the related clinicopathological factors. COX regression analysis was used to determine whether ERCC1, MSH2 and PARP1 were independent prognostic factors.

RESULTS

In the enrolled 111 non-small cell lung cancer patients, the positive expression rate of ERCC1, MSH2 and RARP1 was 33.3%, 36.9% and 55.9%, respectively. ERCC1 (P<0.001) and PARP1 (P=0.033) were found to be correlated with the survival time while there was no correlation for MSH2 (P=0.298). Patients with both ERCC1 and PARP1 negative cancer had significantly longer survival time than those with ERCC1 (P=0.042) or PARP1 (P=0.027) positive alone. Similalry, the survival time of patients with both ERCC1 and PARP1 positive cancer was shorter than those with ERCC1 (P=0.048) or PARP1 (P=0.01) positive alone.

CONCLUSION

Patients with ERCC1 or PARP1 negative non-small cell lung cancer appear to benefit from platinum-based postoperative adjuvant chemotherapy.

Down-regulation of MSH2 expression by Hsp90 inhibition enhances cytotoxicity affected by tamoxifen in human lung cancer cells

The anti-estrogen tamoxifen has been used worldwide as an adjuvant hormone therapeutic agent in the treatment of breast cancer. However, the molecular mechanism of tamoxifen-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Human MutS homolog 2 (MSH2), a crucial element of the highly conserved DNA mismatch repair system, and expression of MSH2 have been down-regulated by Hsp90 function inhibition in human lung cancer. Therefore, in this study, we examined whether MSH2 plays a role in the tamoxifen and Hsp90 inhibitor-induced cytotoxic effect on NSCLC cells. The results showed that treatment with tamoxifen increased MSH2 mRNA and protein levels. The combination treatment with PI3K inhibitors (LY294002 or wortmannin) or knockdown AKT expression by specific small interfering RNA could decrease tamoxifen-induced MSH2 expression. Both knocking down MSH2 expression and co-treatment of PI3K inhibitors enhanced the cytotoxicity and cell growth inhibition of tamoxifen. Compared to a single agent alone, tamoxifen combined with an Hsp90 inhibitor resulted in cytotoxicity and cell growth inhibition synergistically in NSCLC cells, accompanied with reduced MSH2 expression. These findings may have implications for the rational design of future drug regimens incorporating tamoxifen and Hsp90 inhibitors for the treatment of NSCLC.

The role of DNA repair pathways in cisplatin resistant lung cancer

Platinum chemotherapeutic agents such as cisplatin are currently used in the treatment of various malignancies such as lung cancer. However, their efficacy is significantly hindered by the development of resistance during treatment. While a number of factors have been reported that contribute to the onset of this resistance phenotype, alterations in the DNA repair capacity of damaged cells is now recognised as an important factor in mediating this phenomenon. The mode of action of cisplatin has been linked to its ability to crosslink purine bases on the DNA, thereby interfering with DNA repair mechanisms and inducing DNA damage. Following DNA damage, cells respond by activating a DNA-damage response that either leads to repair of the lesion by the cell thereby promoting resistance to the drug, or cell death via activation of the apoptotic response. Therefore, DNA repair is a vital target to improving cancer therapy and reduce the resistance of tumour cells to DNA damaging agents currently used in the treatment of cancer patients. To date, despite the numerous findings that differential expression of components of the various DNA repair pathways correlate with response to cisplatin, translation of such findings in the clinical setting are still warranted. The identification of alterations in specific proteins and pathways that contribute to these unique DNA repair pathways in cisplatin resistant cancer cells may potentially lead to a renewed interest in the development of rational novel therapies for cisplatin resistant cancers, in particular, lung cancer.

[Advance of postoperative adjuvant therapy in non-small cell lung cancer]

肺癌可分为非小细胞肺癌（non-small cell lung cancer, NSCLC）和小细胞肺癌，其发病率和死亡率均高居恶性肿瘤首位。本文主要就NSCLC术后辅助化疗的地位确立、辅助化疗的合适人群和化疗方案选择以及相关生物标志物研究进展作一综述。

Systems biology of cisplatin resistance: past, present and future

The platinum derivative cis-diamminedichloroplatinum(II), best known as cisplatin, is currently employed for the clinical management of patients affected by testicular, ovarian, head and neck, colorectal, bladder and lung cancers. For a long time, the antineoplastic effects of cisplatin have been fully ascribed to its ability to generate unrepairable DNA lesions, hence inducing either a permanent proliferative arrest known as cellular senescence or the mitochondrial pathway of apoptosis. Accumulating evidence now suggests that the cytostatic and cytotoxic activity of cisplatin involves both a nuclear and a cytoplasmic component. Despite the unresolved issues regarding its mechanism of action, the administration of cisplatin is generally associated with high rates of clinical responses. However, in the vast majority of cases, malignant cells exposed to cisplatin activate a multipronged adaptive response that renders them less susceptible to the antiproliferative and cytotoxic effects of the drug, and eventually resume proliferation. Thus, a large fraction of cisplatin-treated patients is destined to experience therapeutic failure and tumor recurrence. Throughout the last four decades great efforts have been devoted to the characterization of the molecular mechanisms whereby neoplastic cells progressively lose their sensitivity to cisplatin. The advent of high-content and high-throughput screening technologies has accelerated the discovery of cell-intrinsic and cell-extrinsic pathways that may be targeted to prevent or reverse cisplatin resistance in cancer patients. Still, the multifactorial and redundant nature of this phenomenon poses a significant barrier against the identification of effective chemosensitization strategies. Here, we discuss recent systems biology studies aimed at deconvoluting the complex circuitries that underpin cisplatin resistance, and how their findings might drive the development of rational approaches to tackle this clinically relevant problem.

Quantitative CT variables enabling response prediction in neoadjuvant therapy with EGFR-TKIs: are they different from those in neoadjuvant concurrent chemoradiotherapy?

Background and Purpose

To correlate changes of various CT parameters after the neoadjuvant treatment in patients with lung adenocarcinoma with pathologic responses, focused on their relationship with different therapeutic options, particularly of EGFR-TKI and concurrent chemoradiation therapy (CCRT) settings.

Materials and Methods

We reviewed pre-operative CT images of primary tumors and surgical specimens obtained after neoadjuvant therapy (TKI, n = 23; CCRT, n = 28) from 51 patients with lung adenocarcinoma. Serial changes in tumor volume, density, mass, skewness/kurtosis, and size-zone variability/intensity variability) were assessed from CT datasets. The changes in CT parameters were correlated with histopathologic responses, and the relationship between CT variables and histopathologic responses was compared between TKI and CCRT groups.

Results

Tumor volume, mass, kurtosis, and skewness were significant predictors of pathologic response in CCRT group in univariate analysis. Using multivariate analysis, kurtosis was found to be independent predictor. In TKI group, intensity variability and size-zone variability were significantly decreased in pathologic responder group. Intensity variability was found to be an independent predictor for pathologic response on multivariate analysis.

Conclusions

Quantitative CT variables including histogram or texture analysis have potential as a predictive tool for response evaluation, and it may better reflect treatment response than standard response criteria based on size changes.

Early-stage non-small-cell lung cancer: overview of adjuvant chemotherapy and promising advances

SUMMARY Adjuvant cisplatin-based chemotherapy for early-stage non-small-cell lung cancer has become standard of care, after three recent meta-analyses validated survival benefit of approximately 5% at 5 years. Subgroup analyses, however, demonstrated that the benefit appears largely confined to patients with stage II disease; however, 25–30% of patients with stage I disease are at high risk of relapse and death within 5 years. Therefore, there is a need to predict more accurately which patients are likely to relapse after surgery and thus benefit from adjuvant therapy. Recent studies indicate that molecular biomarkers, gene-expression profiling and gene-mutation analysis may not only identify those tumors that are more likely to respond to adjuvant chemotherapy, but also to specific cytotoxic agents. These novel bioanalyses will allow physicians to deliver personalized medicine that utilizes cancer therapeutic drugs more cost effectively, thereby improving response rates and, hopefully, conferring survival advantage.

Predictors of biomarkers guiding targeted therapeutic strategies in locally advanced lung cancer

Lung cancer accounts for the majority of cancer-related deaths worldwide. We sought out to summarize the current state of molecular predictors for response and toxicity in locally advanced lung cancer. Several changes have been introduced in recent years in the standard-of-care treatment of advanced non-small cell lung cancer based on the identification of specific molecular alterations that determine response probability to certain therapies. Eligibility for these treatments is assessed by a biomarker test, evaluating if the molecular alteration is present or not in a patient's tumor. In particular, tissue testing for epidermal growth factor receptor and anaplastic lymphoma kinase alterations is currently recommended for certain patients with advanced non-small cell lung cancer, whereas excision repair cross-complementation group 1 and ribonucleotide reductase 1 as markers for outcome after platinum and gemcitabine therapy are promising but are currently not recommended outside a clinical trial. However, their application to the therapy of locally advanced disease is still mostly investigational. Moreover, additional candidate markers for response and toxicity for locally advanced lung cancer are under further investigation.

Early-stage non-small cell lung cancer: surgery, stereotactic radiosurgery, and individualized adjuvant therapy

Despite cures in early stage (IA-IIB) non-small cell lung cancer (NSCLC), the 5-year survival rate is only 36%-73%. Surgical resection via lobectomy is the treatment of choice in early-stage NSCLC, with the goal being complete anatomic resection of the tumor and mediastinal lymph node evaluation. Newer technologies, including the minimally invasive thoracoscopic approach and the many techniques available to stage the mediastinum, have introduced advantages over traditional approaches in achieving this goal. The advent of stereotactic ablative radiotherapy (SABR) has changed how we treat those patients who cannot undergo surgery secondary to comorbidities or patient preference. SABR allows for precise radiation delivery in a short course and at high doses. Adjuvant cisplatin-based chemotherapy is the standard of care for completely resected high-risk stage IB and stage II NSCLC based on a ~5% improvement in 5-year overall survival. The concept of customized adjuvant chemotherapy is emerging, and we will explore the potential value of targeting tumor mutations with available drugs (ie, epidermal growth factor receptor [EGFR] mutations with erlotinib), a strategy that for the moment should be restricted to clinical trials.

Strategies for improving outcomes in NSCLC: a look to the future

Advances in the management of non-small cell lung cancer (NSCLC) over the past 30 years have led to small increases in 5-year survival rates across Europe, though further improvements may require new treatment strategies. In order to improve efficiency and reduce the cost of development, future trials for new targeted agents in NSCLC should aim to recruit patients on the basis of tumour biology rather than clinical characteristics. However, identification of predictive biomarkers is required to maximise the benefits of new approaches and expedite the drug development process. Nevertheless, the NSCLC landscape is changing rapidly, and recent improvements in our understanding of the molecular biology of the disease will help in the identification of novel targeted agents as well as assisting in the development of personalised strategies for the numerous small subsets of defined NSCLC. Progress in imaging and treatment delivery is also likely to improve outcomes for patients with the disease. This article outlines recent progress in the treatment of NSCLC, identifies current challenges and describes proposals for improving the future management of the disease. It is hoped that implementation of some of these strategies will go some way to improving the outlook for patients with NSCLC.