Tumor BRCA1, RRM1 and RRM2 mRNA expression levels and clinical response to first-line gemcitabine plus docetaxel in non-small-cell lung cancer patients

Olaparib maintenance versus placebo in platinum-sensitive non-small cell lung cancer: the Phase 2 randomized PIPSeN trial

BACKGROUND

Platinum-sensitivity is a phenotypic biomarker of Poly (ADP-ribose) polymerase inhibitors (PARPi) sensitivity in histotypes where PARPi are approved. Approximately one-third of non-small cell lung cancers (NSCLC) are platinum-sensitive. The double-blind, randomized phase II PIPSeN (NCT02679963) study evaluated olaparib, a PARPi, as maintenance therapy for patients with platinum-sensitive advanced NSCLC.

METHODS

Chemonaïve patients with ECOG performance status of 0-1, platinum-sensitive, EGFR- and ALK-wild-type, stage IIIB-IV NSCLC were randomized (R) to receive either olaparib (O) maintenance or a placebo (P). The primary objective was progression-free survival (PFS) from R. Secondary objectives included overall survival (OS) and safety. With an anticipated hazard ratio of 0.65, 144 patients were required to be randomized, and approximately 500 patients enrolled.

RESULTS

The trial was prematurely terminated because anti-PD(L)1 therapy was approved during the trial recruitment. A total of 182 patients were enrolled, with 60 patients randomized: 33 and 27 in the O and P arms, respectively. Patient and tumor characteristics were well-balanced between arms, except for alcohol intake (33% vs 11% in the O and P arms, respectively, p = 0.043). The median PFS was 2.9 and 2.0 months in the O and P arms, respectively (logrank p = 0.99). The median OS was 9.4 and 9.5 months in the O and P arms, respectively (p = 0.28). Grade ≥3 toxicities occurred in 15 and 8 patients in O and P arms, with no new safety concerns.

CONCLUSION

PIPSeN was terminated early after enrollment of only 50% of the pre-planned population, thus being statistically underpowered. Olaparib maintenance did neither improve median PFS nor OS in this patient population.

Novel Lymphocyte-Independent Antitumor Activity by PD-1 Blocking Antibody against PD-1+ Chemoresistant Lung Cancer Cells

PURPOSE

Antibodies against the lymphocyte PD-1 (aPD-1) receptor are cornerstone agents for advanced non-small cell lung cancer (NSCLC), based on their ability to restore the exhausted antitumor immune response. Our study reports a novel, lymphocyte-independent, therapeutic activity of aPD-1 against NSCLC, blocking the tumor-intrinsic PD-1 receptors on chemoresistant cells.

EXPERIMENTAL DESIGN

PD-1 in NSCLC cells was explored in vitro at baseline, including stem-like pneumospheres, and following treatment with cisplatin both at transcriptional and protein levels. PD-1 signaling and RNA sequencing were assessed. The lymphocyte-independent antitumor activity of aPD-1 was explored in vitro, by PD-1 blockade and stimulation with soluble ligand (PD-L1s), and in vivo within NSCLC xenograft models.

RESULTS

We showed the existence of PD-1+ NSCLC cell subsets in cell lines and large in silico datasets (Cancer Cell Line Encyclopedia and The Cancer Genome Atlas). Cisplatin significantly increased PD-1 expression on chemo-surviving NSCLC cells (2.5-fold P = 0.0014), while the sequential treatment with anti-PD-1 Ab impaired their recovery after chemotherapy. PD-1 was found to be associated with tumor stemness features. PD-1 expression was enhanced in NSCLC stem-like pneumospheres (P < 0.0001), significantly promoted by stimulation with soluble PD-L1 (+27% ± 4, P < 0.0001) and inhibited by PD-1 blockade (-30% ± 3, P < 0.0001). The intravenous monotherapy with anti-PD-1 significantly inhibited tumor growth of NSCLC xenografts in immunodeficient mice, without the contribution of the immune system, and delayed the occurrence of chemoresistance when combined with cisplatin.

CONCLUSIONS

We report first evidence of a novel lymphocyte-independent activity of anti-PD-1 antibodies in NSCLC, capable of inhibiting chemo-surviving NSCLC cells and exploitable to contrast disease relapses following chemotherapy. See related commentary by Augustin et al., p. 505.

Mechanisms used by cancer cells to tolerate drug-induced replication stress

Activation of oncogenes in cancer cells forces cell proliferation, leading to DNA replication stress (RS). As a consequence, cancer cells heavily rely on the intra S-phase checkpoint for survival. This fundamental principle formed the basis for the development of inhibitors against key players of the intra S-phase checkpoint, ATR and CHK1. These drugs are often combined with chemotherapeutic drugs that interfere with DNA replication to exacerbate RS and exhaust the intra S-phase checkpoint in cancer cells. However, drug resistance impedes efficient clinical use, suggesting that some cancer cells tolerate severe RS. In this review, we describe how an increased nucleotide pool, boosted stabilization and repair of stalled forks and firing of dormant origins fortify the RS response in cancer cells. Notably, the vast majority of the genes that confer RS tolerance are regulated by the E2F and NRF2 transcription factors. These transcriptional programs are frequently activated in cancer cells, allowing simultaneous activation of multiple tolerance avenues. We propose that the E2F and NRF2 transcriptional programs can be used as biomarker to select patients for treatment with RS-inducing drugs and as novel targets to kill RS-tolerant cancer cells. Together, this review aims to provide a framework to maximally exploit RS as an Achilles' heel of cancer cells.

BRCA1 expression associated with the prognostic value of platinum-based chemotherapy for stage II-IV non-small cell lung cancer: A meta-analysis

PURPOSE

To explore the relationship between breast cancer susceptibility gene 1 (BRCA1) expression and the prognostic value of platinum-based chemotherapy for stage II-IV non-small cell lung cancer (NSCLC).

METHODS

PubMed, Web of Science, Embase, and Cochrane Library were searched from inception to August 2021, for retrieving literature related to BRCA1 expression and prognostic value of platinum-based chemotherapy in NSCLC patients. Stata 15.0 was employed for statistical analysis.

RESULTS

A total of 15 articles were included. Compared with the low BRCA1 expression, its high expression negatively affected the overall survival of NSCLC patients treated with platinum-based chemotherapy (hazard ratio (HR) = 1.53, 95% confidence interval (CI): 1.01-2.31, P < 0.05). No significant difference was identified in the effect of both low and high BRCA1 expression on event-free survival (HR = 1.73, 95% CI: 0.98-3.05, P > 0.05). Subgroup analysis showed that significant differences existed in overall survival and event-free survival in Caucasian population; that is, compared with low BRCA1 expression, its high expression negatively affected the overall survival (HR = 1.79, 95% CI: 1.15-2.79, P < 0.05) and event-free survival (HR = 2.39, 95% CI: 1.43-3.97, P < 0.05). Nevertheless, there were no significant differences in overall survival and event-free survival in China.

CONCLUSION

BRCA1 expression is correlated with the prognostic value of platinum-based chemotherapy for stage II-IV NSCLC patients. In Caucasian population, compared with low BRCA1 expression, its high expression has a negative effect on the overall survival and event-free survival in stage II-IV NSCLC patients after platinum-based chemotherapy; however, this correlation was not found in China.

mTORC2 regulates ribonucleotide reductase to promote DNA replication and gemcitabine resistance in non-small cell lung cancer

Ribonucleotide reductase (RNR) is the key enzyme that catalyzes the production of deoxyribonucleotides (dNTPs) for DNA replication and it is also essential for cancer cell proliferation. As the RNR inhibitor, Gemcitabine is widely used in cancer therapies, however, resistance limits its therapeutic efficacy and curative potential. Here, we identified that mTORC2 is a main driver of gemcitabine resistance in non-small cell lung cancers (NSCLC). Pharmacological or genetic inhibition of mTORC2 greatly enhanced gemcitabine induced cytotoxicity and DNA damage. Mechanistically, mTORC2 directly interacted and phosphorylated RNR large subunit RRM1 at Ser 631. Ser631 phosphorylation of RRM1 enhanced its interaction with small subunit RRM2 to maintain sufficient RNR enzymatic activity for efficient DNA replication. Targeting mTORC2 retarded DNA replication fork progression and improved therapeutic efficacy of gemcitabine in NSCLC xenograft model in vivo. Thus, these results identified a mechanism through mTORC2 regulating RNR activity and DNA replication, conferring gemcitabine resistance to cancer cells.

Mechanisms of resistance to chemotherapy in non-small cell lung cancer

Non-small cell lung cancer (NSCLC), which represents 80-85% of lung cancer cases, is one of the leading causes of human death worldwide. The majority of patients undergo an intensive and invasive treatment regimen, which may include radiotherapy, chemotherapy, targeted therapy, immunotherapy, or a combination of these, depending on disease stage and performance status. Despite advances in therapeutic regimens, the 5-year survival of NSCLC is approximately 20-30%, largely due to diagnosis at advanced stages. Conventional chemotherapy is still the standard treatment option for patients with NSCLC, especially those with advanced disease. However, the emergence of resistance to chemotherapeutic agents (chemoresistance) poses a significant obstacle to the management of patients with NSCLC. Therefore, to develop efficacious chemotherapeutic approaches for NSCLC, it is necessary to understand the mechanisms underlying chemoresistance. Several mechanisms are known to mediate chemoresistance. These include altered cellular targets for chemotherapy, decreased cellular drug concentrations, blockade of chemotherapy-induced cell cycle arrest and apoptosis, acquisition of epithelial-mesenchymal transition and cancer stem cell-like phenotypes, deregulated expression of microRNAs, epigenetic modulation, and the interaction with tumor microenvironments. In this review, we summarize the mechanisms underlying chemoresistance and tumor recurrence in NSCLC and discuss potential strategies to avoid or overcome chemoresistance.

Inhibiting RRM2 to enhance the anticancer activity of chemotherapy

RRM2, the small subunit of ribonucleotide reductase, is identified as a tumor promotor and therapeutic target. It is common to see the overexpression of RRM2 in chemo-resistant cancer cells and patients. RRM2 mediates the resistance of many chemotherapeutic drugs and could become the predictor for chemosensitivity and prognosis. Therefore, inhibition of RRM2 may be an effective means to enhance the anticancer activity of chemotherapy. This review tries to discuss the mechanisms of RRM2 overexpression and the role of RRM2 in resistance to chemotherapy. Additionally, we compile the studies on small interfering RNA targets RRM2, RRM2 inhibitors, kinase inhibitors, and other ways that could overcome the resistance of chemotherapy or exert synergistic anticancer activity with chemotherapy through the expression inhibition or the enzyme inactivation of RRM2.

Downregulation of miR-125b-5p and Its Prospective Molecular Mechanism in Lung Squamous Cell Carcinoma

Background: To explore the clinical significance of miR-125b-5p and its potential mechanisms in lung squamous cell carcinoma (LUSC). Materials and Methods: An integrated analysis of data from in-house quantitative real-time polymerase chain reaction (qRT-PCR), microRNA-sequencing, and microarray assays to appraise the expression level of miR-125b-5p in LUSC tissues compared to adjacent noncancerous controls. The authors identified the candidate targets of miR-125b-5p and conducted functional analysis using computational biology strategies from gene ontology, the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, disease ontology (DO), and protein-protein interaction (PPI) network analyses to investigate the prospective mechanisms. Results: According to qRT-PCR results, the expression level of miR-125b-5p was markedly decreased in LUSC tissues compared to noncancerous control tissues. Receiver operating characteristic and summary receiver operating characteristic analyses showed that miR-125b-5p had good specificity and sensitivity for distinguishing LUSC tissue from noncancerous lung tissue. The standard mean difference revealed that men and women with lower expression levels of miR-125b-5p may have a higher risk for LUSC. KEGG analysis and DO analysis intimated that target genes were evidently enriched in pyrimidine metabolism and pancreatic carcinoma. The PPI network of the top assembled KEGG pathway indicated that RRM2, UMPS, UCK2, and CTPS1 were regarded as crucial target genes for miR-125b-5p, and RRM2 was eventually deemed a key target. Conclusions: The authors' findings implicate a low expression level of miR-125b-5p in LUSC. A tumor-suppressive role of miR-125b-5p is proposed, based on its effects on LUSC tumor growth, clinical stage progression, and lymph node metastasis.

Identification of PDL1-Related Biomarkers to Select Lung Adenocarcinoma Patients for PD1/PDL1 Inhibitors

PD1/PDL1 inhibitors have been adopted for the treatment of advanced non-small-cell lung cancer, and PDL1 expression has been investigated as a predictive biomarker for PD1/PDL1 inhibitor therapy. However, PDL1 lacks diagnostic accuracy in differentiating patients who are likely or unlikely to benefit. So, it is urgent and clinically significant to identify other associated predictive biomarkers for PD1/PDL1 inhibitor therapy. Our work was to identify PDL1-related biomarkers that could improve the patient selection for PD1/PDL1 inhibitor treatment. We obtained 500 genes coexpressed with PDL1 in lung adenocarcinoma from the TCGA database. Then, we identified 125 out of 500 genes differentially expressed in lung adenocarcinoma. A total of 39 genes were distinguished with prognostic value and associated with overall survival. Median survival time analysis based on gene expression level, protein-protein interaction analysis, GO and KEGG enrichment analyses, and significant GO and KEGG function consistency analyses were conducted to screen candidate biomarkers. Three candidate genes, BRCA1, BRIP1, and EREG, were identified to be functionally significantly coexpressed with PDL1. Functional enrichment analysis and protein-protein interaction networks further showed that these genes mainly participated in immune response and cell activation. Additionally, to find potential adjuvant therapeutic targets in PD1/PDL1 inhibitor treatment, we performed transcription factor prediction analysis. A group of negative differential expression but PDL1-related biomarkers has been identified, which might help to assess the clinical management of lung cancer patients. A combination of potential biomarkers and adjuvant therapeutic targets with PDL1 will predict the response to PD1/PDL1 inhibitors more accurately and help with the patient selection for more personalized immune checkpoint inhibitor treatment.

A Six-Gene Signature Predicts Survival of Adenocarcinoma Type of Non-Small-Cell Lung Cancer Patients: A Comprehensive Study Based on Integrated Analysis and Weighted Gene Coexpression Network

Background and Goals. To identify a multigene signature model for prognosis of non-small-cell lung cancer (NSCLC) patients, we first found 2146 consensus differentially expressed genes (DEGs) in NSCLC overlapped in Gene Expression Omnibus (GEO) and TCGA lung adenocarcinoma (LUAD) datasets using integrated analysis. We constructed a weighted gene coexpression network (WGCN) using the consensus DEGs and identified the module significantly associated with pathological M stage and consisted of 61 genes. After univariate Cox regression analysis and subsequent stepwise model selection by the Akaike information criterion (AIC) and multivariate Cox hazard model analysis, an mRNA signature model which calculated prognostic score was generated: prognostic score = (-0.2491 × EXP_RRAGB) + (-0.0679 × EXP_RSPH9) + (-0.2317 × EXP_RPS6KL1) + (-0.1035 × EXP_RXFP1) + 0.1571 × EXP_RRM2 + 0.1104 × EXP_RTL1, where EXP is the fragments per kilobase million (FPKM) value of the mRNA included in the model. The prognostic model separated NSCLC patients in the TCGA-LUAD dataset into the low- and high-risk score groups with a median prognostic score of 0.972. Higher scores predicted higher risk. The area under ROC curve (AUC) was 0.994 or 0.776 in predicting the 1- to 10-year survival of NSCLC patients. The prognostic performance of this prognostic model was validated by an independent GSE11969 dataset of NSCLC adenocarcinoma with AUC values between 0.822 and 0.755 in predicting 1- to 10-year survival of NSCLC. These results suggested that the six-gene signature functioned as an independent biomarker to predict the overall survival of NSCLC adenocarcinoma.

Inhibitory Effect of Oat Bran Ethanol Extract on Survival and Gemcitabine Resistance of Pancreatic Cancer Cells

Pancreatic cancer (PC) is one of the most aggressive malignancies in the world. Gemcitabine (Gem), a nucleoside pyrimidine analogue, is a first-line chemotherapeutic drug for PC, but the tumor response rate of Gem is very low and resistance to Gem has emerged as a major problem in the treatment of PC. Oat bran, used as animal and human food, has been found to be beneficial to health. In this study, effects of oat bran ethanol extract (OBE) on PC cells and Gem-resistant PC cells were investigated in vitro. OBE decreased cell survival and colony forming ability of PC cells, without any cytotoxicity on the normal pancreatic cells. Flow cytometry analysis and TUNEL assay showed that the OBE reduced G1/S phase transition and induced death in PC cells through AMPK activation and downregulation of JNK. Additionally, OBE could overcome Gem resistance through reduction in RRM1/2 expression and showed synergistic effect by combinatorial treatment with Gem on Gem-resistant PC cells. Additionally, LC-MS data showed that avenacoside A was a component of OBE. Thus, this study elucidated the anti-proliferative effect of OBE and synergistic effect of OBE with Gem on PC cells and Gem-resistant cells.

Integrative Analysis Reveals Across-Cancer Expression Patterns and Clinical Relevance of Ribonucleotide Reductase in Human Cancers

Mining cancer-omics databases deepens our understanding of cancer biology and can lead to potential breakthroughs in cancer treatment. Here, we propose an integrative analytical approach to reveal across-cancer expression patterns and identify potential clinical impacts for genes of interest from five representative public databases. Using ribonucleotide reductase (RR), a key enzyme in DNA synthesis and cancer-therapeutic targeting, as an example, we characterized the mRNA expression profiles and inter-component associations of three RR subunit genes and assess their differing pathological and prognostic significance across over 30-types of cancers and their related subtypes. Findings were validated by immunohistochemistry with clinical tissue samples (n = 211) collected from multiple cancer centers in China and with clinical follow-up. Underlying mechanisms were further explored and discussed using co-expression gene network analyses. This framework represents a simple, efficient, accurate, and comprehensive approach for cancer-omics resource analysis and underlines the necessity to separate the tumors by their histological or pathological subtypes during the clinical evaluation of molecular biomarkers.

Identification of Genes Associated with Lung Adenocarcinoma Prognosis

OBJECTIVE

Lung cancer is the most prevalent cancer in the world, and lung adenocarcinoma is the most common lung cancer subtype. Identification and determination of relevant prognostic markers are the key steps to personalized cancer management.

METHODS

We collected the gene expression profiles from 265 tumor tissues of stage I patients from The Cancer Genome Atlas (TCGA) databases. Using Cox regression model, we evaluated the association between gene expression and the overall survival time of patients adjusting for gender and age at initial pathologic diagnosis.

RESULTS

Age at initial pathologic diagnosis was identified to be associated with the survival, while gender was not. We identified that 15 genes were significantly associated with overall survival time of patients (FDR < 0.1). The 15-mRNA signature- based risk score was helpful to distinguish patients of high-risk group from patients of low-risk group.

CONCLUSION

Our findings reveal novel genes associated with lung adenocarcinoma survival and extend our understanding of how gene expression contributes to lung adenocarcinoma survival. These results are helpful for the prediction of the prognosis and personalized cancer management.

RRM1 expression and the clinicopathological characteristics of patients with non-small cell lung cancer treated with gemcitabine

Background

The usefulness of ribonucleotide reductase catalytic subunit M1 (RRM1) for predicting the therapeutic effects of gemcitabine-containing chemotherapy in patients with non-small cell lung cancer (NSCLC) remains controversial. RRM1-positive patients show unique clinicopathological features.

Methods

Here, we performed a meta-analysis to systematically evaluate the relationship between RRM1 expression and the clinicopathological characteristics of NSCLC patients treated with gemcitabine-containing regimens. A comprehensive electronic and manual search was performed to identify relevant articles. The pooled relative risk (RR) and 95% CI were used to estimate the relation between the clinicopathological characteristics of NSCLC patients and RRM1 expression.

Results

The study included 31 observational studies and 3,667 patients. The analysis showed no significant association between RRM1 expression and pathological type, stage, and smoking status; however, RRM1 positivity was significantly lower in women than in men (43.0% vs 51.7%, RR=0.84, 95% CI: 0.74-0.94, P=0.004).

Conclusion

The present pooled analyses demonstrated that RRM1 positivity in women with advanced NSCLC was associated with a higher rate of response to gemcitabine-containing regimens. Immunohistochemistry may be valuable to prescreen for RRM1 expression in clinical practice, whereas PCR can be routinely used as a verification method. These findings will help design suitable molecular-targeted therapies for NSCLC.

Nucleobase and Nucleoside Analogues: Resistance and Re-Sensitisation at the Level of Pharmacokinetics, Pharmacodynamics and Metabolism

Antimetabolites, in particular nucleobase and nucleoside analogues, are cytotoxic drugs that, starting from the small field of paediatric oncology, in combination with other chemotherapeutics, have revolutionised clinical oncology and transformed cancer into a curable disease. However, even though combination chemotherapy, together with radiation, surgery and immunotherapy, can nowadays cure almost all types of cancer, we still fail to achieve this for a substantial proportion of patients. The understanding of differences in metabolism, pharmacokinetics, pharmacodynamics, and tumour biology between patients that can be cured and patients that cannot, builds the scientific basis for rational therapy improvements. Here, we summarise current knowledge of how tumour-specific and patient-specific factors can dictate resistance to nucleobase/nucleoside analogues, and which strategies of re-sensitisation exist. We revisit well-established hurdles to treatment efficacy, like the blood-brain barrier and reduced deoxycytidine kinase activity, but will also discuss the role of novel resistance factors, such as SAMHD1. A comprehensive appreciation of the complex mechanisms that underpin the failure of chemotherapy will hopefully inform future strategies of personalised medicine.

Prognostic value of ribonucleotide reductase subunit M1 (RRM1) in non-small cell lung cancer: A meta-analysis

BACKGROUND

Ribonucleotide reductase subunit 1 (RRM1) is a potential prognostic factor for non-small cell lung cancer (NSCLC). This study evaluates prognostic value of RRM1 in NSCLC patients by meta-analyzing outcomes reported in literature.

METHOD

Data were acquired from research articles retrieved after literature search in online databases. Random effects meta-analyses were conducted by pooling hazard ratios (HR). Meta-analyses of standardized mean differences (SMD) were used to evaluate overall survival (OS) and progression-free survival (PFS) between low and high RRM1 expression groups. Metaregression analyses were conducted to evaluate the factors that could affect prognostic relationship of RRM1 with treatment and survival outcomes.

RESULTS

23 studies (3148 patients) were included. RRM1 expression was not meaningfully associated with prognosis of NSCLC even when the reference (HR = 1) was either low RRM1 expression (0.918 [95% CI 0.833, 1.003]) or high RRM1 expression (0.834 [0.625, 1.043]). OS was significantly longer in low RRM1 expression group compared to high RRM1 expression group (SMD 0.73 [0.36, 1.09]; P < 0.0001). PFS was not significantly different between low and high RRM1 expression groups (SMD 0.08 [-0.29, 0.45]; p = 0.68). Age was inversely associated with HR (p = 0.001) even when reference was low RRMI (p = 0.027) or high RRM1 (p = 0.006). Age was positively associated with OS in both low and high RRM1 groups.

CONCLUSION

In meta-analysis of studies which used gemcitabine-based therapies, higher RRM1 expression is found to associated with shorter OS but not PFS. HR depicting relationship between RRM1 expression and OS/PFS/treatment response could not demonstrate a prognostic role of RRM1 in NSCLC patients.

Association of BRCA1, ERCC1, RAP80, PKM2, RRM1, RRM2, TS, TSP1, and TXR1 mRNA expression levels between primary tumors and infiltrated regional lymph nodes in patients with resectable non-small cell lung cancer

Differences in gene expression levels between the primary tumors (PTs) and matched regional lymph nodal metastases (LNs) in patients with totally excised non-small cell lung cancer (NSCLC) were explored. Microdissected formalin-fixed paraffin-embedded (FFPE) samples from (PT) and their matched infiltrated LNs, from 239 patients [183 (with matched PT and LNs samples)-case and 56 PT only samples-control cohorts] were analyzed for BRCA1, ERCC1, RAP80, PKM2, RRM1, RRM2, TS, TSP1, and TXR1 mRNA expression by quantitative real-time polymerase-chain reaction (PCR). Moderately positive correlation between the expression of each gene in the PT and the matched LNs was observed. Concordance rates between the PT and the LNs were: BRCA1 (67.7%), ERCC1 (68.4%), PKM2 (63.4%), RAP80 (68.8%), RRM1 (70.9%), RRM2 (69%), TS (72.9%), TSP1 (69.8%), TXR1 (63.7%). Expression levels and their differences were correlated with Relapse-Free Survival (RFS) and Overall Survival (OS). High BRCA1 PT in patients with squamous histology was associated with increased OS (p = 0.036). High TSP1 PT levels were shown to be the only independent prognostic factor for OS and RFS (p = 0.023 and p = 0.007). PKM2 low levels in both PT and matched LNs were associated with better OS irrespective of the underlying histology (p = 0.031). RRM1 discordant levels between PT and matched LNs were associated with worse OS in squamous tumors (p = 0.019) compared to patients with both low expression in PT and LN.TXR1 high levels in both PT and matched LNs were associated with better OS in patients with squamous tumors (p = 0.007).These findings indicate that there is different gene expression between PT and matched LNs which may affect the outcome in early NSCLC and therefore PT's molecular biology should not be the sole determinant for prognostication.

Combination of using prodrug-modified cationic liposome nanocomplexes and a potentiating strategy via targeted co-delivery of gemcitabine and docetaxel for CD44-overexpressed triple negative breast cancer therapy

In this study, novel prodrug-modified cationic liposome nanocomplexes (Combo NCs) were reported for gemcitabine (GEM) and docetaxel (DTX) co-delivery. This nanoplatform exhibited multiple favorable characteristics, such as a 'green' fabrication with a one-step chemical reaction, appropriate size (∼200nm) and distribution (PDI<0.2), low zeta potential (-31.1mv), high drug-loading efficiency (9.3% GEM plus 3.1% DTX, wt%) and pH and enzymatic dual-stimulus-responsive release properties. Immunofluorescence and cellular uptake studies showed that Combo NCs efficiently targeted overexpressed CD44 in MDA-MB-231 carcinoma. In vitro studies revealed that Combo NCs played a critical role in the synergistic induction of cytotoxicity, apoptosis and inhibition of wound healing. Combo NCs were confirmed to exhibit great potency for increasing S phase arrest and remodeling the CDA and dCK balance by decreasing the mRNA expression of CDA down to 0.09-fold and increasing the mRNA expression of dCK by 1.36-fold, remarkably increasing the dCK/CDA ratio to 15.3-fold compared with the blank control. The biodistribution results obtained in vivo revealed an effective accumulation in tumor foci. All of these advantages of Combo NCs contributed to their remarkable anti-tumor efficacy without systemic toxicity as well as their apoptosis-enhancing and anti-proliferative capacities, as determined by TUNEL and Ki67 immunohistochemistry in vivo. Consequently, such a rationally contemplated co-delivery system demonstrated the promising potential of clinical applications for triple-negative breast cancer therapy.

STATE OF SIGNIFICANCE

The Combo NCs were innovatively applied for co-delivery of hydrophilic GEM and hydrophobic DTX. The ester bond linking and shielding effect of HA-GEM made the carriers achieve synchronous release properties, which was determined in in vitro release study. Due to the HA modification, the vectors own great potency for positive targeting to CD44 overexpressed triple-negative breast cancer cells MDA-MB-231. Cytotoxicity and apoptosis studies confirmed the targeting effect and synergism between two drugs. Interestingly, we found in cell cycle study, drug combinations (free combination or Combo NCs) didn't show a rise in G2M phase, which was significantly higher when treated DTX alone. We further discovered the role of DTX in combinations may involve in modulating GEM associated enzymes thus enhancing the efficacy of GEM. Consequently, this nanoplatform provided a novel solution for achieving targeted co-delivery and potentiating effect in cancer therapy.

Tumour growth-suppressive effect of arsenic trioxide in squamous cell lung carcinoma

Lung squamous cell carcinoma (SCC) is the second most common subtype of non-small cell lung carcinoma. The anticancer effects of arsenic trioxide (ATO) in lung adenocarcinoma and small-cell lung cancer have previously been reported; however its effects in SCC remain unclear. An MTT assay and western blot analysis were performed to determine cell viability and protein expression, respectively, in the SK-MES-1 and SW900 SCC cell lines following treatment with ATO. Phosphatidylserine externalization, mitochondrial membrane depolarization and cell cycle distribution were studied using flow cytometry and the in vivo effects of ATO on tumour growth were investigated with a xenograft model. The results demonstrated that SK-MES-1 and SW900 SCC cells were sensitive to clinically relevant concentrations of ATO. ATO induced apoptosis, mitochondrial membrane depolarization and G₂/M arrest. In addition, treatment with ATO resulted in the downregulation of X-linked inhibitor of apoptosis, B-cell lymphoma-2 (Bcl-2), E2F transcription factor 1 (E2F1), thymidylate synthase and ribonucleotide reductase M1 in addition to the upregulation of Bcl-2 antagonist/killer protein, cleaved poly ADP-ribose polymerase and cleaved caspase 3 in a cell-line specific manner. In the SW900 xenograft model, tumour growth was inhibited by ATO with the formation of apoptotic bodies and downregulation of Bcl-2 and E2F1. In conclusion, ATO suppresses the growth of SCC in vitro and in vivo.

Low RAP80 mRNA expression correlates with shorter survival in sporadic high-grade serous ovarian carcinoma

OBJECTIVE

Homologous recombination (HR) is frequently impaired in sporadic high-grade serous ovarian carcinoma (sHGSOC) due to deficiencies in BRCA1/2 genes, a situation associated with hypersensitivity to platinum compounds. Alterations in other genes can also cause HR deficiency. Preclinical data show that RAP80 is an HR-pathway-related gene that influences BRCA1 activity. RAP80 has been reported to affect outcome in some solid neoplasms. This study investigates the role of RAP80 in sHGSOC survival.

METHODS

mRNA expression of RAP80 was analyzed in tumor samples from 35 patients who postoperatively received standard platinum-based chemotherapy. The effects of RAP80 expression on progression-free survival (PFS) and overall survival (OS) were examined by means of Cox regressions. The clinical variables known to have prognostic value (FIGO stage, residual disease at surgery, and debulking surgery) were included as covariates in the analysis. BRCA1 was analyzed given the moderate correlations with RAP80.

RESULTS

Median follow-up, PFS and OS were 61.3, 20.2 and 62.8 months, respectively. Low RAP80 expression levels were associated with shorter PFS (HR = 1.449, p = 0.007) and OS (HR = 1.331, p = 0.047).

CONCLUSIONS

This is the first study to show a potential prognostic role of RAP80 expression in patients with HGSOC. The results suggest that HR deficiency due to low RAP80 expression is not associated with hypersensitivity to platinum compounds in sHGSOC.

Evaluation of plasma microRNA levels to predict insensitivity of patients with advanced lung adenocarcinomas to pemetrexed and platinum

Pemetrexed combined with platinum is a first-line therapy used to treat patients with advanced non-small cell lung cancer (NSCLC) that exhibit negative or unknown epidermal growth factor receptor (EGFR) mutational status or anaplastic lymphoma kinase (ALK) rearrangements. Lung adenocarcinoma (LAC) is the primary type of NSCLC. In order to prevent overtreatment, it is necessary to identify patients with LAC who may not benefit from certain chemotherapies. Patients recruited in the present study (n=129) were diagnosed with advanced LAC and received first-line pemetrexed and platinum-based chemotherapy. A microRNA (miR) microarray was used to screen the plasma miR expression profiles in a screening set of eight patients prior to and following treatment. Specifically, plasma miR-25, miR-21, miR-27b, miR-326, miR-483-5p and miR-920 were selected for reverse transcription-quantitative polymerase chain reaction analysis in a training set (n=44) prior to treatment. The screening and training set patients were all non-smokers with no prior history of serious or chronic disease. The ∆∆Cq values of these miRs were compared between the group that showed benefit from pemetrexed and platinum treatment and the group that did not. Consequently, the ∆∆Cq values of miR-25, miR-21, miR-27b and miR-326 were further determined in a validation set (n=77). The results of the present study demonstrate that plasma expression levels of miR-25, miR-21, miR-27b and miR-326, in the training and validation sets prior to treatment, were significantly different between the benefit and non-benefit groups (P≤0.001). The expression of miR-25, miR-21, miR-27b and miR-326 was upregulated in the non-benefit group and this elevation was positively correlated with decreased progression-free survival (PFS; P≤0.001). In addition, the predictive power of each miR was evaluated through receiver operating characteristic curves, in which miR-25 exhibited the highest degree of accuracy (area under the curve, 0.926; 95% confidence interval, 0.881-0.971). These results indicate that overexpression of plasma miR-25, miR-21, miR-27b and miR-326, prior to treatment, in patients with advanced LAC is predictive of non-benefit from first-line pemetrexed and platinum-based chemotherapy, and is associated with decreased PFS. Among these four miRs, miR-25 exhibited the highest degree of accuracy in predicting insensitivity, suggesting it is the most promising biomarker.

RRM1 *151A>T, RRM1 -756T>C, and RRM1 -585T>Gis associated with increased susceptibility of lung cancer in Chinese patients

Ribonucleotide reductase M1 (RRM1) is a crucial gene in DNA repair. Recent studies have shown that RRM1 expression can be a powerful predictor of survival or chemotherapy sensitivity in patients presenting with carcinomas who are treated with adjuvant gemcitabine-based chemotherapy including lung cancer. However, the relationship between the single nucleotide polymorphisms (SNP) of RRM1 and the susceptibility of lung cancer to chemotherapy has not been well addressed. We detected six tag SNPs of RRM1 genotypes in a cohort of 1007 patients with primary lung cancer and 1007 age- and sex-matched population controls using SNaPshot detection technology. Logistic regression, odds ratios (OR), and 95% confidence intervals were calculated to estimate lung cancer risk associated with SNP genotypes and haplotypes, after adjusting for case-control matching factors. Compared with the T/T and A/T genotype of RRM1 *151A>T, the A/A genotype had an increased risk for overall lung cancer (adjusted OR, 1.33). Additionally, the T/T+T/C genotypes of RRM1 -756T>C were risk factors that increased the susceptibility to lung cancer (adjusted OR 1.54, as compared with the C/C genotype). While the T/T+G/T genotypes of RRM1 -585T>G behaved as protective factors to increase the susceptibility to lung cancer (adjusted OR 0.44, as compared with the C/C genotype). In summary, this is the first study to systematically identify the relationship between the polymorphisms of RRM1 and individual susceptibility to lung cancer. It is anticipated that the RRM1 *151A>T, RRM1 -756T>C, and RRM1 -585T>G polymorphisms will improve the predictive prognosis of lung cancer sensitivity.

Predictive value of BRCA1 expression on the efficacy of chemotherapy based on anti-microtubule agents: a pooled analysis across different malignancies and agents

BACKGROUND

Breast cancer susceptibility gene 1 (BRCA1) expression has been suggested as a predictor in anti-neoplastic treatment with anti-microtubule agents. However, the existing evidence is conflicting. Consulting the literature, we sought to examine the true impact of BRCA1 expression on the efficacy of anti-microtubule agents.

METHODS

Medline by PubMed and Embase databases were searched for eligible studies. The primary endpoints were objective response rate (ORR) and progression free survival (PFS). Additional subgroup analyses stratified for detection methods, regimen, and patient origin were also performed.

RESULTS

A total of 13 relevant studies involving a total of 1,490 cases were enrolled. Involved agents included paclitaxel, docetaxel and vinorelbine; Malignancies included non-small cell lung cancer, gastric cancer, esophageal carcinoma, ovarian carcinoma, malignant pleural mesothelioma, breast cancer, and small cell lung cancer. Through meta-analyses, we observed a potentially greater ORR in the population with high BRCA1 expression vs. low BRCA1 expression (OR 1.63, 95% CI: 0.92 to 2.88, P=0.09) but the heterogeneity is severe (P=0.01; I(2)=61%). Similar results were observed in PFS (high vs. low expression, HR 0.93, 95% CI: 0.75 to 1.15, P=0.49; heterogeneity, P<0.01, I(2)=75%). After stratification by testing methods, a significantly higher ORR in the population with high BRCA1 expression was shown in the subgroup using mRNA as a quantitative method (OR 2.90, 95% CI: 1.92 to 4.39, P<0.01; I(2)=0) whereas the difference in the subgroup using immunohistochemistry (IHC) was not significant (OR 0.60, 95% CI: 0.33 to 1.10, P=0.10; I(2)=0). Stratification by regimen (platinum-based vs. non platinum-based) and patient origin (Asian vs. Caucasian) did not reduce the heterogeneity.

CONCLUSIONS

Although the predictive value of BRCA1 expression on the anti-microtubule chemotherapy remained uncertain based on overall results, our exploratory analyses suggested that detection using mRNA might be a preferred technique, however, further validation is required to substantiate our findings.

Expression Levels of DNA Damage Repair Proteins Are Associated With Overall Survival in Platinum-Treated Advanced Urothelial Carcinoma

BACKGROUND

Combination platinum chemotherapy is standard first-line therapy for metastatic urothelial carcinoma (mUC). Defining the platinum response biomarkers for patients with mUC could establish personalize medicine and provide insights into mUC biology. Although DNA repair mechanisms have been hypothesized to mediate the platinum response, we sought to analyze whether increased expression of DNA damage genes would correlate with worse overall survival (OS) in patients with mUC.

PATIENTS AND METHODS

We retrospectively identified a clinically annotated cohort of patients with mUC, who had been treated with first-line platinum combination chemotherapy. A tissue microarray was constructed from formalin-fixed paraffin-embedded tissue from the primary tumor before treatment. Immunohistochemical analysis of the following DNA repair proteins was performed: ERCC1, RAD51, BRCA1/2, PAR, and PARP-1. Nuclear and cytoplasmic expression was analyzed using multispectral imaging. Nuclear staining was used for the survival analysis. Cox regression analysis was used to evaluate the associations between the percentage of positive nuclear staining and OS in multivariable analysis, controlling for known prognostic variables.

RESULTS

In a cohort of 104 patients with mUC, a greater percentage of nuclear staining of ERCC1 (hazard ratio [HR], 2.7; 95% confidence interval [CI], 1.5-4.9; P = .0007), RAD51 (HR, 5.6; 95% CI, 1.7-18.3; P = .005), and PAR (HR, 2.2; 95% CI, 1.1-4.4; P = .026) was associated with worse OS. BRCA1, BRCA2, and PARP-1 expression was not associated with OS (P = .76, P = .38, and P = .09, respectively). A greater percentage of combined ERCC1 and RAD51 nuclear staining was strongly associated with worse OS (P = .005).

CONCLUSION

A high percentage of nuclear staining of ERCC1, RAD51, and PAR, assessed by immunohistochemistry, correlated with worse OS for patients with mUC treated with first-line platinum combination chemotherapy, supporting the evidence of the DNA repair pathways' role in the prognosis of mUC. We also report new evidence that RAD51 and PAR might play a role in the platinum response. Additional prospective studies are required to determine the prognostic or predictive nature of these biomarkers in mUC.

BIM and mTOR expression levels predict outcome to erlotinib in EGFR-mutant non-small-cell lung cancer

BIM is a proapoptotic protein that initiates apoptosis triggered by EGFR tyrosine kinase inhibitors (TKI). mTOR negatively regulates apoptosis and may influence response to EGFR TKI. We examined mRNA expression of BIM and MTOR in 57 patients with EGFR-mutant NSCLC from the EURTAC trial. Risk of mortality and disease progression was lower in patients with high BIM compared with low/intermediate BIM mRNA levels. Analysis of MTOR further divided patients with high BIM expression into two groups, with those having both high BIM and MTOR experiencing shorter overall and progression-free survival to erlotinib. Validation of our results was performed in an independent cohort of 19 patients with EGFR-mutant NSCLC treated with EGFR TKIs. In EGFR-mutant lung adenocarcinoma cell lines with high BIM expression, concomitant high mTOR expression increased IC50 of gefitinib for cell proliferation. We next sought to analyse the signalling pattern in cell lines with strong activation of mTOR and its substrate P-S6. We showed that mTOR and phosphodiesterase 4D (PDE4D) strongly correlate in resistant EGFR-mutant cancer cell lines. These data suggest that the combination of EGFR TKI with mTOR or PDE4 inhibitors could be adequate therapy for EGFR-mutant NSCLC patients with high pretreatment levels of BIM and mTOR.

Customizing chemotherapy in non-small cell lung cancer: the promise is still unmet

A combination of cytotoxic agents with cis-platin remains the cornerstone of treatment for the vast majority of patients with non-small cell lung cancer (NSCLC). Molecular analysis of the primary may lead better prognostication and eventually in more accurate therapeutic approaches. Data from retrospective analysis of randomized trials as well as large patients' series have suggested that chemotherapy may be customized upon molecular-genetic analysis of the tumor cells. The Spanish Lung Cancer Group (SLCG) in collaboration with French lung Cancer Group (FLCG) had conduct randomized, phase III, biomarkers-driven trial and supported simultaneously a randomized phase II trial in collaborating centers in China. Despite the evidence from the preclinical data and the results from the retrospective studies, the results of these trials published recently in Annals of Oncology were in favor of 'standard approach'. The present commentary tries to give some explanation for the disappointing results, provide potential solution for the future trials and explain why the vision of customizing treatment is still alive.

Expression of Ribonucleotide Reductase Subunit-2 and Thymidylate Synthase Correlates with Poor Prognosis in Patients with Resected Stages I-III Non-Small Cell Lung Cancer

Biomarkers can help to identify patients with early-stages or locally advanced non-small cell lung cancer (NSCLC) who have high risk of relapse and poor prognosis. To correlate the expression of seven biomarkers involved in DNA synthesis and repair and in cell division with clinical outcome, we consecutively collected 82 tumour tissues from radically resected NSCLC patients. The following biomarkers were investigated using IHC and qRT-PCR: excision repair cross-complementation group 1 (ERCC1), breast cancer 1 (BRCA1), ribonucleotide reductase subunits M1 and M2 (RRM1 and RRM2), subunit p53R2, thymidylate synthase (TS), and class III beta-tubulin (TUBB3). Gene expression levels were also validated in an available NSCLC microarray dataset. Multivariate analysis identified the protein overexpression of RRM2 and TS as independent prognostic factors of shorter overall survival (OS). Kaplan-Meier analysis showed a trend in shorter OS for patients with RRM2, TS, and ERCC1, BRCA1 overexpressed tumours. For all of the biomarkers except TUBB3, the OS trends relative to the gene expression levels were in agreement with those relative to the protein expression levels. The NSCLC microarray dataset showed RRM2 and TS as biomarkers significantly associated with OS. This study suggests that high expression levels of RRM2 and TS might be negative prognostic factors for resected NSCLC patients.

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.

Serum Protein Pattern Could Predict the Therapeutic Effect of First-Line Pemetrexed/Cisplatin Chemotherapy in Patients With Lung Adenocarcinoma

Background

In patients with advanced non-squamous non-small cell lung cancer (NSCLC), a pemetrexed/cisplatin (PP) regimen is considered as one of the preferred first-line treatments. However, only about half of the treated patients respond, and there is no clinically useful marker that can predict the response to the regimen.

Methods

We established a potential pattern for the prediction of efficacy of first-line PP chemotherapy in patients with lung adenocarcinoma, by using artificial neural networks (ANNs) analysis of surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) in this preliminary study.

Results

The samples were randomly divided into training set and test set. From the test set, through cross-validation, the established protein pattern for PP separated the responders from the non-responders with a sensitivity of 95.8% and a specificity of 90.0%.

Conclusion

It could be helpful for oncologists to select patients who could benefit from PP chemotherapy.

Predicting chemosensitivity to gemcitabine and cisplatin based on gene polymorphisms and mRNA expression in non-small-cell lung cancer cells

Aim: We used a panel of 17 non-small-cell lung cancer cell lines to investigate whether the presence of polymorphisms in the RRM1, ERCC1, ABCB1 and MTHFR genes and alterations in their mRNA expression can affect the in vitro chemosensitivity to cisplatin and gemcitabine. Materials & methods: Polymorphisms in these genes were evaluated by direct sequencing. mRNA expression levels were assessed by realtime PCR. In vitro chemosensitivity to cisplatin and gemcitabine was expressed as IC50 values, using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. Results: There was a significant, positive correlation between RRM1 mRNA expression and IC50 values for gemcitabine (r = 0.6533, p = 0.0045), and there was a significant, negative correlation between ABCB1 mRNA expression and IC50 values for cisplatin (r = -0.5459, p = 0.0287). When examining the association between the polymorphisms and IC50, we found that only the MTHFR 1298A>C polymorphism showed a tendency to be more chemosensitive to gemcitabine (p = 0.0440). Conclusion: These in vitro results suggest that mRNA expression levels of the RRM1 and ABCB1 genes may be useful indicators of chemosensitivity to gemcitabine and cisplatin, respectively. The MTHFR 1298A>C polymorphism was associated with gemcitabine chemosensitivity, which require further functional analysis with co-expressed genes and should be explored in prospective clinical studies to determine its potential clinical application as a predictive biomarker.

Original submitted 11 February 2014; Revision submitted 3 November 2014

Robust selection of cancer survival signatures from high-throughput genomic data using two-fold subsampling

Identifying relevant signatures for clinical patient outcome is a fundamental task in high-throughput studies. Signatures, composed of features such as mRNAs, miRNAs, SNPs or other molecular variables, are often non-overlapping, even though they have been identified from similar experiments considering samples with the same type of disease. The lack of a consensus is mostly due to the fact that sample sizes are far smaller than the numbers of candidate features to be considered, and therefore signature selection suffers from large variation. We propose a robust signature selection method that enhances the selection stability of penalized regression algorithms for predicting survival risk. Our method is based on an aggregation of multiple, possibly unstable, signatures obtained with the preconditioned lasso algorithm applied to random (internal) subsamples of a given cohort data, where the aggregated signature is shrunken by a simple thresholding strategy. The resulting method, RS-PL, is conceptually simple and easy to apply, relying on parameters automatically tuned by cross validation. Robust signature selection using RS-PL operates within an (external) subsampling framework to estimate the selection probabilities of features in multiple trials of RS-PL. These probabilities are used for identifying reliable features to be included in a signature. Our method was evaluated on microarray data sets from neuroblastoma, lung adenocarcinoma, and breast cancer patients, extracting robust and relevant signatures for predicting survival risk. Signatures obtained by our method achieved high prediction performance and robustness, consistently over the three data sets. Genes with high selection probability in our robust signatures have been reported as cancer-relevant. The ordering of predictor coefficients associated with signatures was well-preserved across multiple trials of RS-PL, demonstrating the capability of our method for identifying a transferable consensus signature. The software is available as an R package rsig at CRAN (http://cran.r-project.org).

Prognostic significance of BRCA1, ERCC1, RRM1, and RRM2 in patients with advanced non-small cell lung cancer receiving chemotherapy

The aim of this study was to examine the prognostic value of breast cancer susceptibility gene 1 (BRCA1), excision repair cross-complementation 1 (ERCC1), ribonucleotide reductase subunit M1 (RRM1), and ribonucleotide reductase subunit M2 (RRM2) in patients with advanced non-small cell lung cancer (NSCLC) who received platinum-based chemotherapy. A total of 214 patients with histologically or cytologically confirmed advanced NSCLC were enrolled in this study. The relative complementary DNA (cDNA) quantification for BRCA1, ERCC1, RRM1, and RRM2 was conducted using a fluorescence-based, real-time detection method, and β-actin was used as a reference gene. A strong correlation was observed between ERCC1 and RRM1 messenger RNA (mRNA) levels (P = 0.0385). There were inverse significant correlations between BRCA1 and ERCC1 (P < 0.0001) or RRM1 (P < 0.0001) mRNA levels. As BRCA1 levels increased, the probability of response increased (odds ratio [OR] = 0.49; P < 0.001) and the risk of progression (hazard ratio [HR] = 1.52; P = 0.034) and death (HR = 1.45; P = 0.024) decreased. As ERCC1, RRM1, and RRM2 levels increased, the probability of response decreased (ERCC1, OR = 0.42, P < 0.001; RRM1, OR = 0.85, P = 0.083; RRM2, OR = 0.42, P = 0.005) and the risk of progression (ERCC1, HR = 1.59, P = 0.002; RRM1, HR = 1.48, P = 0.039; RRM2, HR = 1.49, P = 0.041) and death (ERCC1, HR = 1.62, P = 0.008; RRM1, HR = 1.52, P = 0.023; RRM2, HR = 1.48, P = 0.017) increased. At multivariate analysis, low expression of ERCC1 was shown to be an independent predictive factor for response to chemotherapy (P = 0.018), time to progression (P = 0.025), and overall survival (P = 0.038). Furthermore, concomitant low expression levels of ERCC1, RRM1, and RRM2 and the high expression level of BRCA1 were predictive of a better outcome (P = 0.014). This study suggests that the efficacy of platinum-based chemotherapy can be improved when customized according to the mRNA expression of BRCA1, ERCC1, RRM1, and RRM2.

Second ESMO consensus conference on lung cancer: pathology and molecular biomarkers for non-small-cell lung cancer

To complement the existing treatment guidelines for all tumour types, ESMO organises consensus conferences to focus on specific issues in each type of tumour. The Second ESMO Consensus Conference on Lung Cancer was held on 11-12 May 2013 in Lugano. A total of 35 experts met to address several questions on management of patients with non-small-cell lung cancer (NSCLC) in each of four areas: pathology and molecular biomarkers, early stage disease, locally advanced disease and advanced (metastatic) disease. For each question, recommendations were made including reference to the grade of recommendation and level of evidence. This consensus paper focuses on recommendations for pathology and molecular biomarkers in relation to the diagnosis of lung cancer, primarily non-small-cell carcinomas.

Two biomarker-directed randomized trials in European and Chinese patients with nonsmall-cell lung cancer: the BRCA1-RAP80 Expression Customization (BREC) studies

BACKGROUND

In a Spanish Lung Cancer Group (SLCG) phase II trial, the combination of BRCA1 and receptor-associated protein 80 (RAP80) expression was significantly associated with outcome in Caucasian patients with nonsmall-cell lung cancer (NSCLC). The SLCG therefore undertook an industry-independent collaborative randomized phase III trial comparing nonselected cisplatin-based chemotherapy with therapy customized according to BRCA1/RAP80 expression. An analogous randomized phase II trial was carried out in China under the auspices of the SLCG to evaluate the effect of BRCA1/RAP80 expression in Asian patients.

PATIENTS AND METHODS

Eligibility criteria included stage IIIB-IV NSCLC and sufficient tumor specimen for molecular analysis. Randomization to the control or experimental arm was 1 : 1 in the SLCG trial and 1 : 3 in the Chinese trial. In both trials, patients in the control arm received docetaxel/cisplatin; in the experimental arm, patients with low RAP80 expression received gemcitabine/cisplatin, those with intermediate/high RAP80 expression and low/intermediate BRCA1 expression received docetaxel/cisplatin, and those with intermediate/high RAP80 expression and high BRCA1 expression received docetaxel alone. The primary end point was progression-free survival (PFS).

RESULTS

Two hundred and seventy-nine patients in the SLCG trial and 124 in the Chinese trial were assessable for PFS. PFS in the control and experimental arms in the SLCG trial was 5.49 and 4.38 months, respectively [log rank P = 0.07; hazard ratio (HR) 1.28; P = 0.03]. In the Chinese trial, PFS was 4.74 and 3.78 months, respectively (log rank P = 0.82; HR 0.95; P = 0.82).

CONCLUSION

Accrual was prematurely closed on the SLCG trial due to the absence of clinical benefit in the experimental over the control arm. However, the BREC studies provide proof of concept that an international, nonindustry, biomarker-directed trial is feasible. Thanks to the groundwork laid by these studies, we expect that ongoing further research on alternative biomarkers to elucidate DNA repair mechanisms will help define novel therapeutic approaches.

TRIAL REGISTRATION

NCT00617656/GECP-BREC and ChiCTR-TRC-12001860/BREC-CHINA.

ERCC1 and BRCA1 mRNA expression predicts the clinical outcome of non-small cell lung cancer receiving platinum-based chemotherapy

Objective: We conducted a perspective study to investigate the association between mRNA expression quantities of ERCC1, BRCA1, RRM1 and RRM2 and response to chemotherapy and clinical outcome of advance Non-Small Cell Lung Cancer.(NSCLC).

Methods: Two hundred eight patients who were diagnosed as advanced stage NSCLC were included in our study. A fluorescence-based and real-time detection method was used to determine the relative cDNA quantification for ERCC1, BRCA1, RRM1 and RRM2, and β-actin was used as the reference gene.

Results: The median expression levels of ERCC1, BRCA1, RRM1 and RRM2 mRNA were 0.67±0.17, 0.095±0.012, 0.24±0.17 and 2.45±0.32, respectively. Our study found that the low ERCC1 (OR=1.82, 95% CI=1.01-3.20) and Low BRCA1 (OR=2.53, 95%CI=1.38-4.64) mRNA expression was more likely to response to chemotherapy when compared with high expression, respectively. Multivariate Cox regression analysis indicated that patients with low mRNA expression of ERCC1 and BRCA1 attained 0.43 (OR=0.43, 95%CI=0.27-0.89) and 0.37 (OR=0.37, 95%CI=0.22-0.66) fold risk of death from NSCLC. However, we found RMM1 and RRM2 mRNA expression could not influence the response to chemotherapy and clinical outcome of NSCLC.

Conclusion: ERCC1 and BRCA1 mRNA expression could be important predictive markers for individualized platinum-based chemotherapy for NSCLC patients.

DNA microarray reveals ZNF195 and SBF1 are potential biomarkers for gemcitabine sensitivity in head and neck squamous cell carcinoma cell lines

Gemcitabine is a potential chemotherapy drug for treatment of head and neck squamous cell carcinoma (HNSCC), however, the poor or partial response of HNSCC patients to gemcitabine demonstrated the urgent need for gemcitabine biomarkers to improve the therapy. In present work, 10 HNSCC cell lines were employed to figure out the biomarkers for gemcitabine sensitivity. The sensitivities of these 10 cell lines to gemcitabine and the basal expression of these cell lines was investigated, the correlation between gemcitabine response (IC50 dose) and gene expression was investigated by Pearson correlation and FDR estimation. The top seven positive genes responsible for gemcitabine sensitivity were validated by qPCR in these 10 HNSCC cell lines, while only two genes (SBF1 and ZNF195) were expression-correlated to gemcitabine response. Furthermore, ZNF195 expression was closely associated with gemcitabine sensitivity in the subsequent independent validation in cell lines from various types of cancer. Our work might provide potential biomarkers for gemcitabine sensitivity in HNSCC and various type of cancer.

A critical re-assessment of DNA repair gene promoter methylation in non-small cell lung carcinoma

DNA repair genes that have been inactivated by promoter methylation offer potential therapeutic targets either by targeting the specific repair deficiency, or by synthetic lethal approaches. This study evaluated promoter methylation status for eight selected DNA repair genes (ATM, BRCA1, ERCC1, MGMT, MLH1, NEIL1, RAD23B and XPC) in 56 non-small cell lung cancer (NSCLC) tumours and 11 lung cell lines using the methylation-sensitive high resolution melting (MS-HRM) methodology. Frequent methylation in NEIL1 (42%) and infrequent methylation in ERCC1 (2%) and RAD23B (2%) are reported for the first time in NSCLC. MGMT methylation was detected in 13% of the NSCLCs. Contrary to previous studies, methylation was not detected in ATM, BRCA1, MLH1 and XPC. Data from The Cancer Genome Atlas (TCGA) was consistent with these findings. The study emphasises the importance of using appropriate methodology for accurate assessment of promoter methylation.

Differences in RRM1 protein expression between diagnostic biopsies and resection specimens, and changes during carboplatin and paclitaxel treatment, in non-small-cell lung cancer

AIMS

It is of interest whether expression of potentially predictive biomarkers changes during chemotherapy, for accurate evaluation after first-line chemotherapy. This study aimed to evaluate changes in RRM1 expression during chemotherapy.

MATERIALS AND METHODS

RRM1 immunohistochemistry was performed on tumour samples from a total of 118 NSCLC patients with stage T1-4N0-2M0 disease. Samples were included from 65 patients treated with paclitaxel and carboplatin before surgery [neoadjuvant chemotherapy (NAC) group], and 53 patients who had undergone surgery but not chemotherapy [operation (OP) group].

RESULTS

Discordant RRM1 expression (low versus high) was observed in 32% and 43% of paired diagnostic and subsequent resection specimens in the OP group and NAC group, respectively (P = 0.913). Ten (33%) and 12 (23%) tumours in the NAC group and the OP group, respectively, had increased RRM1 expression in the resection specimens (P = 0.289), and 12 (40%) and 19 (36%) tumours had decreased expression (P = 0.707). Eleven (50%) lymph node metastases had higher RRM1 expression following chemotherapy, and two (7%) had decreased expression.

CONCLUSIONS

The substantial discordance between paired samples emphasizes the need for sufficient tumour tissue in biopsies when RRM1 expression is evaluated. No change in RRM1 expression was observed in primary tumours, but expression seemed to be higher in N2 lymph node metastases following chemotherapy. Tumour heterogeneity and potential post-chemotherapy changes should be considered when RRM1 expression is evaluated.

Gene aberrations of RRM1 and RRM2B and outcome of advanced breast cancer after treatment with docetaxel with or without gemcitabine

Background

The purpose of the present study was to retrospectively evaluate whether copy number changes of the genes encoding the ribonucleotide reductase subunit M1 (RRM1) and/or subunit M2B (RRM2B) predict sensitivity to gemcitabine administered in combination with docetaxel compared to single agent docetaxel in advanced breast cancer patients.

Methods

Primary tumor samples from patients randomly assigned to gemcitabine plus docetaxel or docetaxel alone were analyzed for RRM1 and RRM2B copy number changes using Fluorescence In Situ Hybridization (FISH) technology with probes covering respectively RRM1 at 11p15.5 and a reference probe covering the centromere of chromosome 11 (CEN-11), and RRM2B at 8q22.3 and a reference probe covering the centromere of chromosome 8 (CEN-8). The assays were validated in a material of 60 normal breast samples. Time to progression (TTP) was the primary endpoint. Overall survival (OS) and response rate (RR) were secondary endpoints. Associations between RRM1/CEN-11 and/or RRM2B/CEN-8 ratios and time-to-event endpoints were analyzed by unadjusted and adjusted Cox proportional hazards regression models. Heterogeneity of treatment effects on TTP and OS according to gene status were investigated by subgroup analyses, and the Wald test was applied. All statistical tests were two-sided.

Results

FISH analysis for both RRM1 and RRM2B was successful in 251 patients. RRM1 and RRM2B aberrations (deletions and amplifications) were observed in 15.9% and 13.6% of patients, respectively. RRM1 aberrations were associated with a decreased OS in the time interval 1.5-7.4 years (hazard ratio = 1.72, 95% confidence interval = 1.05-2.79, P = 0.03). RRM2B aberrations alone or in combination with RRM1 aberrations had no prognostic impact in terms of TTP or OS. RR was not different by gene status. No significant differences were detected in TTP or OS within subgroups according to gene status and chemotherapy regimen.

Conclusions

This study demonstrated the presence of RRM1 and RRM2B copy number changes in primary breast tumor specimens. Nevertheless, we found no support of the hypothesis that aberrations of RRM1 or RRM2B, neither individually nor in combination, are associated with an altered clinical outcome following chemotherapy with gemcitabine in combination with docetaxel compared to docetaxel alone in advanced breast cancer patients.

Predictive value of BRCA1, ERCC1, ATP7B, PKM2, TOPOI, TOPΟ-IIA, TOPOIIB and C-MYC genes in patients with small cell lung cancer (SCLC) who received first line therapy with cisplatin and etoposide

BACKGROUND

The aim of the study was to evaluate the predictive value of genes involved in the action of cisplatin-etoposide in Small Cell Lung Cancer (SCLC).

METHODS

184 SCLC patients' primary tumour samples were analyzed for ERCCI, BRCA1, ATP7B, PKM2 TOPOI, TOPOIIA, TOPOIIB and C-MYC mRNA expression. All patients were treated with cisplatin-etoposide.

RESULTS

The patients' median age was 63 years and 120 (65%) had extended stage, 75 (41%) had increased LDH serum levels and 131 (71%) an ECOG performance status was 0-1. Patients with limited stage, whose tumours expressed high ERCC1 (p=0.028), PKM2 (p=0.046), TOPOI (p=0.008), TOPOIIA (p=0.002) and TOPOIIB (p<0.001) mRNA had a shorter Progression Free Survival (PFS). In limited stage patients, high expression of ERCC1 (p=0.014), PKM2 (p=0.026), TOPOIIA (p=0.021) and TOPOIIB (p=0.019) was correlated with decreased median overall survival (mOS) while in patients with extended stage, only high TOPOIIB expression had a negative impact on Os (p=0.035). The favorable expression signature expression signature (low expression of ERCC1, PKM2, TOPOIIA and TOPOIIB) was correlated with significantly better PFS and Os in both LS-SCLC (p<0.001 and p=0.007, respectively) and ES-SCLC (p=0.007 and (p=0.011, respectively) group. The unfavorable expression signature was an independent predictor for poor PFS (HR: 3.18; p=0.002 and HR: 3.14; p=0.021) and Os (HR: 4.35; p=0.001and HR: 3.32; p=0.019) in both limited and extended stage, respectively.

CONCLUSIONS

Single gene's expression analysis as well as the integrated analysis of ERCC1, PKM2, TOPOIIA and TOPOIIB may predict treatment outcome in patients with SCLC. These findings should be further validated in a prospective study.

Re-challenge chemotherapy with gemcitabine plus carboplatin in patients with non-small cell lung cancer

Despite recent improvements to current therapies and the emergence of novel agents to manage advanced non-small cell lung cancer (NSCLC), the patients' overall survival remains poor. Re-challenging with first-line chemotherapy upon relapse is common in the management of small cell lung cancer but is not well reported for advanced NSCLC. NSCLC relapse has been attributed to acquired drug resistance, but the repopulation of sensitive clones may also play a role, in which case re-challenge may be appropriate. Here, we report the results of re-challenge with gemcitabine plus carboplatin in 22 patients from a single institution who had previously received gemcitabine plus platinum in the first-line setting and had either partial response or a progression-free interval of longer than 6 months. In this retrospective study, the charts of patients who underwent second-line chemotherapy for NSCLC in our cancer center between January 2005 and April 2010 were reviewed. All the patients who received a combination of gemcitabine and carboplatin for re-challenge were included in the study. These patients were offered second-line treatment on confirmation of clear radiological disease progression. The overall response rate was 15% and disease control rate was 75%. The median survival time was 10.4 months, with 46% of patients alive at 1 year. These results suggest that re-challenge chemotherapy should be considered in selected patients with radiological partial response or a progression-free survival of longer than 6 months to the initial therapy.

Array analysis for potential biomarker of gemcitabine identification in non-small cell lung cancer cell lines

Gemcitabine is one of the most widely used drugs for the treatment of advanced Non-small cell lung cancer (NSCLC), but modest objective response rate of patients to gemcitabine makes it necessary to identify novel biomarkers for patients who can benefit from gemcitabine-based therapy and to improve the effect of clinical therapy. In this work, 3 NSCLC cell lines displaying different sensitivities to gemcitabine were applied for mRNA and microRNA (miR) expression chips to figure out the biomarkers for gemcitabine sensitivity. Genes whose expression increased dramatically in sensitive cell lines were mainly enriched in cell adhesion (NRP2, CXCR3, CDK5R1, IL32 and CDH2) and secretory granule (SLC11A1, GP5, CD36 and IGF1), while genes with significantly upregulated expression in resistant cell line were mainly clustered in methylation modification (HIST1H2BF, RAB23 and TP53) and oxidoreductase (TP53I3, CYP27B1 and SOD3). The most intriguing is the activation of Wnt/β-catenin signaling in gemcitabine resistant NSCLC cell lines. The miR-155, miR-10a, miR-30a, miR-24-2* and miR-30c-2* were upregulated in sensitive cell lines, while expression of miR-200c, miR-203, miR-885-5p, miR-195 and miR-25* was increased in resistant cell line. Genes with significantly altered expression and putatively mediated by the expression-changed miRs were mainly enriched in chromatin assembly (MAF, HLF, BCL2, and IGSF3), anti-apoptosis (BCL2, IGF1 and IKBKB), protein kinase (NRP2, PAK7 and CDK5R1) (all the above genes were upregulated in sensitive cells) and small GTPase mediated signal transduction (GNA13, RAP2A, ARHGAP5 and RAB23, down-regulated in sensitive cells). Our results might provide potential biomarkers for gemcitabine sensitivity prediction and putative targets to overcome gemcitabine resistance in NSCLC patients.

Breast cancer susceptibility gene 1 (BRCA1) predict clinical outcome in platinum- and toxal-based chemotherapy in non-small-cell lung cancer (NSCLC) patients: a system review and meta-analysis

The recent studies have evaluated the relationship between BRCA1 expression and clinical outcome of chemotherapy (mainly focused on platinum-based and toxal-based treatment) in NSCLC patients, but the results were inconclusive and controversial. Our aim of this study was to evaluate this association by literature based system review and meta-analysis.PubMed, EMBASE and the China National Knowledge Infrastructure (CNKI) databases were used to retrieve the relevant articles. The interested outcome included objective response rate (ORR), overall survival (OS) and event-free survival (EFS). The pooled odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI) ware estimated.After specific inclusion and exclusion criteria, 23 studies fulfilled the criteria and were included in our analysis. In 17 platinum-based studies, low/negative BRCA1 was in favor of better ORR (OR=1.70, 95%CI=1.32-2.18), longer OS and EFS (HR=1.58, 95%CI=1.27-1.97, and HR=1.60, 95%CI=1.07-2.39 for OS and EFS, respectively). In 4 toxal-based chemotherapy studies, the patients with high/positive BRCA1 had better ORR (OR=0.41, 95%CI=0.26-0.64), OS and EFS were not evaluated as the insufficient data available.Overall, BRCA1 might be a useful biomarker to predict clinical outcome for personal chemotherapy in NSCLC patients in the future.

Biomarkers and molecular testing for early detection, diagnosis, and therapeutic prediction of lung cancer

The search for biomarkers in the management of lung cancer involves the use of multiple platforms to examine changes in gene, protein, and microRNA expression. Multiple studies have been published in an attempt to describe early detection, diagnostic, prognostic, and predictive biomarkers using chiefly tissues and blood elements. Studies are characterized by a lack of commonality of specific biomarkers, and a lack of validated, clinically useful markers. The future of biomarker discovery as a means of tailoring therapy for patients with lung cancer will involve next-generation sequencing along with collaborative efforts to integrate and validate candidate markers.

Individualized Chemotherapy in Advanced NSCLC Patients Based on mRNA Levels of BRCA1 and RRM1

OBJECTIVE

Experimental evidence suggests that the overexpression of breast cancer-specific tumor suppressor protein 1 (BRCA1) gene enhances sensitivity to docetaxel and resistance to cisplatin and ribonucleotide reductase M1 (RRM1) gene overexpression enhances resistance to gemcitabine. To further examine the effect of BRCA1 and RRM1 mRNA levels on outcome in advanced non-small cell lung cancer (NSCLC), we performed this non-randomized phase II clinical trial which tested the hypothesis that customized therapy would confer improved outcome over non-customized therapy.

METHODS

RNA was isolated from fresh tumor tissue. Patients received chemotherapy regimen based on their BRCA1 and RRM1 mRNA levels: both low-cisplatin plus gemcitabine (GP); both high-vinorelbine plus cisplatin (NP); BRCA1 low and RRM1 high-cisplatin plus docetaxel (TP); BRCA1 high and RRM1 low-vinorelbine plus gemcitabine (GN).

RESULTS

From Dec 2005 to Nov 2008, 94 metastatic and locally advanced NSCLC patients from our institute were enrolled in this study. The median age was 58 years old. Among them, 21 patients received GP, 30 patients received TP and 43 patients received NP chemotherapy. GP group had a higher response rate, and longer median time to progression (TTP) and median overall survival (OS) time than the other 2 groups. The response rates in the GP, TP and NP groups were 42.9%, 36.7% and 27.9%, respectively (P=0.568). The median TTP was 5.6, 5.0, 4.8 months (P=0.975), respectively, and the median OS time was 12.5, 11.0, 9.7 months (P=0.808), respectively.

CONCLUSION

Chemotherapy customized according to BRCA1 and RRM1 expression levels is associated with higher response rate and longer TTP and OS time in the GP group. This suggests that BRCA1 and RRM1 mRNA levels could be used as biomarkers in individual therapy in NSCLC.

Chemotherapy effectiveness after first-line gefitinib treatment for advanced lepidic predominant adenocarcinoma (formerly advanced bronchioloalveolar carcinoma): exploratory analysis of the IFCT-0401 trial

HYPOTHESIS

This study explored whether chemotherapy after first-line gefitinib was effective in patients with advanced lepidic predominant adenocarcinoma (LPA), formerly advanced bronchioloalveolar carcinoma, who were enrolled in the Intergroupe Francophone de Cancérologie Thoracique (IFCT)-0401 trial.

METHODS

Overall, 88 patients presenting advanced LPA were enrolled in the IFCT-0401 trial, receiving gefitinib as first-line therapy. No predefined second-line treatment was mandatory in the case of progression or limiting toxicity under gefitinib. However, the carboplatin plus paclitaxel regimen was recommended for patients with a performance status (PS) 0 or 1 and gemcitabine monotherapy for those with a PS 2. For these patients, data concerning treatment efficacy was collected from the IFCT-0401 trial database.

RESULTS

In total, 47 patients (53%) received second-line treatment after the failure of gefitinib, with 43 having PS 0 or 1. Regarding treatment, 43 were treated with chemotherapy, with 38 receiving a platinum-doublet regimen (taxane-based, n = 29; gemcitabine-based, n = 9) and five receiving monotherapy (gemcitabine, n = 3; pemetrexed, n = 2). The overall response rate (ORR) to chemotherapy was 21% (95% confidence interval [CI]: 10-36), disease control rate 56% (95% CI: 40-71), and median progression-free survival (PFS) 3.0 months (95% CI: 2.4-4.9). For patients receiving a platinum doublet (n = 38), ORR was 21% (95% CI: 10-37), with disease control rate being 55% (95% CI: 38-71), and median PFS 2.9 months (95% CI: 2.4-4.4). For patients receiving taxane-based regimen (n = 29) and gemcitabine-based regimen (n = 12), ORR was 28% and 0%, respectively, with a median PFS of 3.3 and 2.0 months, respectively, (p = 0.0243). The two patients receiving pemetrexed experienced a prolonged response. Multivariate Cox model analysis revealed that only the use of taxane-based chemotherapy or pemetrexed was related to PFS.

CONCLUSION

Platinum-doublet chemotherapy showed some effectiveness in treating advanced LPA patients after first-line gefitinib. Our findings also suggest that taxane-based chemotherapy and pemetrexed should be investigated further in future clinical trials.