Prognostic value of ERCC1, RRM1, and TS proteins in patients with resected non-small cell lung cancer

lncRNA cytoskeleton regulator RNA (CYTOR): Diverse functions in metabolism, inflammation and tumorigenesis, and potential applications in precision oncology

Long non-coding RNAs (lncRNAs) are a novel class of non-coding RNA (ncRNA), that have been studied extensively in the field of tumor research in recent years. In the case of tumor-associated lncRNAs, lncRNA cytoskeleton regulator RNA (CYTOR) displays extensive functions in tumorigenesis, including invasion, metastasis, malignant proliferation, glycolysis, and inflammatory response. Moreover, the dysregulation of CYTOR is closely related to clinicopathological characteristics, such as tumor stage, lymph node metastasis and infiltration, and poor prognosis of tumor patients. In this review, we provide a novel strategy to summarize the biological functions and clinical value of CYTOR in tumors through an overview of the literature combined with gene set enrichment analysis. A deeper understanding of the role of CYTOR in tumorigenesis may provide new diagnostic, prognostic and therapeutic markers for human tumors.

miR-145-5p Targets Sp1 in Non-Small Cell Lung Cancer Cells and Links to BMI1 Induced Pemetrexed Resistance and Epithelial-Mesenchymal Transition

Pemetrexed is a folic acid inhibitor used as a second-line chemotherapeutic agent for the treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC), which accounts for 85% of lung cancers. However, prolonged treatment with pemetrexed may cause cancer cells to develop resistance. In this study, we found increased expressions of BMI1 (B Lymphoma Mo-MLV insertion region 1 homolog) and Sp1 and a decreased expression of miR-145-5p was found in pemetrexed-resistant A400 cells than in A549 cells. Direct Sp1 targeting activity of miR-145-5p was demonstrated by a luciferase based Sp1 3'-UTR reporter. Changed expression of miR-145-5p in A400 or A549 cells by transfection of miR-145-5p mimic or inhibitor affected the sensitivity of the cells to pemetrexed. On the other hand, the overexpression of Sp1 in A549 cells caused the decreased sensitivity to pemetrexed, induced cell migratory capability, and epithelial-mesenchymal transition (EMT) related transcription factors such as Snail Family Transcriptional Repressor 1 and Zinc Finger E-Box Binding Homeobox 1. In addition, the overexpression of BMI1 in the A549 cells resulted in an increase in Sp1 and a decrease in miR-145-5p accompanied by the elevations of cell proliferation and EMT transcription factors, which could be reduced by the overexpression of miR-145-5p or by treatment with the Sp1 inhibitor of mithramycin A. In conclusion, the results of this study suggest that the downregulation of miR-145-5p by BMI1 overexpression could lead to the enhanced expression of Sp1 to induce the EMT process in pemetrexed-resistant NSCLC cells. These results suggest that increasing miR-145-5p expression by delivering RNA drugs may serve as a sensitizing agent for pemetrexed-resistant NSCLC patients.

How Cancer Cells Resist Chemotherapy: Design and Development of Drugs Targeting Protein-Protein Interactions

Background:

Resistance toward chemotherapeutics is one of the main obstacles on the way to effective cancer treatment. Personalization of chemotherapy could improve clinical outcome. However, despite preclinical significance, most of the potential markers have failed to reach clinical practice partially due to the inability of numerous studies to estimate the marker’s impact on resistance properly.

Objective:

The analysis of drug resistance mechanisms to chemotherapy in cancer cells, and the proposal of study design to identify bona fide markers.

Methods:

A review of relevant papers in the field. A PubMed search with relevant keywords was used to gather the data. An example of a search request: drug resistance AND cancer AND paclitaxel.

Results:

We have described a number of drug resistance mechanisms to various chemotherapeutics, as well as markers to underlie the phenomenon. We also proposed a model of a rational-designed study, which could be useful in determining the most promising potential biomarkers.

Conclusion:

Taking into account the most reasonable biomarkers should dramatically improve clinical outcome by choosing the suitable treatment regimens. However, determining the leading biomarkers, as well as validating of the model, is a work for further investigations.

Novel drug-resistance mechanisms of pemetrexed-treated non-small cell lung cancer

Pemetrexed (PEM) improves the overall survival of patients with advanced non-small cell lung cancer (NSCLC) when administered as maintenance therapy. However, PEM resistance often appears during the therapy. Although thymidylate synthase is known to be responsible for PEM resistance, no other mechanisms have been investigated in detail. In this study, we explored new drug resistance mechanisms of PEM-treated NSCLC using two combinations of parental and PEM-resistant NSCLC cell lines from PC-9 and A549. PEM increased the apoptosis cells in parental PC-9 and the senescent cells in parental A549. However, such changes were not observed in the respective PEM-resistant cell lines. Quantitative RT-PCR analysis revealed that, besides an increased gene expression of thymidylate synthase in PEM-resistant PC-9 cells, the solute carrier family 19 member1 (SLC19A1) gene expression was markedly decreased in PEM-resistant A549 cells. The siRNA-mediated knockdown of SLC19A1 endowed the parental cell lines with PEM resistance. Conversely, PEM-resistant PC-9 cells carrying an epidermal growth factor receptor (EGFR) mutation acquired resistance to a tyrosine kinase inhibitor erlotinib. Although erlotinib can inhibit the phosphorylation of EGFR and Erk, it is unable to suppress the phosphorylation of Akt in PEM-resistant PC-9 cells. Additionally, PEM-resistant PC-9 cells were less sensitive to the PI3K inhibitor LY294002 than parental PC-9 cells. These results indicate that SLC19A1 negatively regulates PEM resistance in NSCLC, and that EGFR-tyrosine-kinase-inhibitor resistance was acquired with PEM resistance through Akt activation in NSCLC harboring EGFR mutations.

Relationship between LAT1 expression and resistance to chemotherapy in pancreatic ductal adenocarcinoma

PURPOSE

L-type amino acid transporter 1 (LAT1) is linked to tumor cell proliferation, angiogenesis, and survival in various human cancers. Although the expression of LAT1 was identified as a significant prognostic predictor after surgery in patients with pancreatic ductal adenocarcinoma (PDAC), little is known about the clinical significance of LAT1 as a chemotherapeutic resistance factor in PDAC.

METHODS

A total of 110 patients with surgically resected PDAC were retrospectively reviewed as the training set. Immunohistochemical staining of resected tumor specimens was assessed using anti-LAT1 antibodies. In vitro analysis of chemotherapy resistance and LAT1 function using PDAC cell lines was also performed.

RESULTS

The rate of high expression of LAT1 was 64.1% (71/110). The high expression of LAT1 protein was significantly associated with tumor differentiation, tumor depth (T factor), lymph node metastasis, venous invasion, recurrence, and clinical response. By multivariate analysis, LAT1 was validated as an independent prognostic factor for predicting worse survival after surgery. We analyzed the TCGA data set and obtained similar results that the survival rates of SLC7A5 high expression group were poorer than that of low expression group. LAT1 could successfully predict the outcome of patients who received adjuvant chemotherapy after surgery (n = 88) and systemic chemotherapy after recurrence (n = 56). All patients with high LAT1 expression were non-responders, whereas approximately 30% of the patients with low LAT1 expression responders (p = 0.0002). By analyzing the TCGA online database, it was found that LAT1 closely correlated with hypoxia-induced genes, such as PTGES, PYGL, and KPNA2.

CONCLUSION

LAT1 as an independent prognostic marker is a potential molecular targeting gene to reduce chemoresistance and tumor growth in patients with PDAC, supported by our in vitro study.

Gemcitabine-Based Chemotherapy in Adrenocortical Carcinoma: A Multicenter Study of Efficacy and Predictive Factors

CONTEXT

Adrenocortical carcinoma (ACC) is rare and confers an unfavorable prognosis in advanced stages. Other than combination chemotherapy with cisplatin, etoposide, doxorubicin, and mitotane, the second- and third-line regimens are not well-established. Gemcitabine (GEM)-based chemotherapy was suggested in a phase 2 clinical trial with 28 patients. In other solid tumors, human equilibrative nucleoside transporter type 1 (hENT1) and/or ribonucleotide reductase catalytic subunit M1 (RRM1) expression have been associated with resistance to GEM.

OBJECTIVE

To assess the efficacy of GEM-based chemotherapy in ACC in a real-world setting and the predictive role of molecular parameters.

DESIGN

Retrospective multicenter study.

SETTING

Referral centers of university hospitals.

PATIENTS AND MATERIALS

A total of 145 patients with advanced ACC were treated with GEM-based chemotherapy (132 with concomitant capecitabine). Formalin-fixed paraffin-embedded tumor material was available for 70 patients for immunohistochemistry.

OUTCOME MEASURES

The main outcome measures were progression-free survival (PFS) and an objective response to GEM-based chemotherapy. The secondary objective was the predictive role of hENT1 and RRM1.

RESULTS

The median PFS for the patient population was 12 weeks (range, 1 to 94). A partial response or stable disease was achieved in 4.9% and 25.0% of cases, with a median duration of 26.8 weeks. Treatment was generally well tolerated, with adverse events of grade 3 or 4 occurring in 11.0% of cases. No substantial effect of hENT1 and/or RRM1 expression was observed in response to GEM-based chemotherapy.

CONCLUSIONS

GEM-based chemotherapy is a well-tolerated, but modestly active, regimen against advanced ACC. No reliable molecular predictive factors could be identified. Owing to the scarce alternative therapeutic options, GEM-based chemotherapy remains an important option for salvage treatment for advanced ACC.

Effects of p38MAPK-mediated excision repair cross-complementation 1 expression on prognosis of patients with non-small cell lung cancer

The present study aimed to investigate the effects of excision repair cross-complementation 1 (ERCC1) expression on the prognosis of patients with non-small cell lung cancer (NSCLC). A total of 140 patients with NSCLC who underwent radical resection were included. Immunohistochemical staining was performed on the tissue specimens obtained from patients and correlation analysis was used to determine the association between ERCC1 expression and clinicopathological characteristics. Cell proliferation was assessed using an MTT assay. The mRNA and protein expression levels were detected using reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. The expression of ERCC1 was demonstrated to be significantly elevated in tumor tissue compared with adjacent tissue samples. Furthermore, the expression of ERCC1 in squamous carcinoma was significantly higher compared with in adenocarcinoma samples. The expression of ERCC1 in patients who smoke was significantly higher compared with in the non-smokers. The 3-year disease-free survival (DFS) and overall survival (OS) for ERCC1-negative patients were higher compared with ERCC1-positive patients. Multivariate analysis demonstrated that ERCC1 expression, pathological staging, and tumor staging were important prognostic factors for NSCLC. Subgroup analysis revealed that the 3-year OS rate for ERCC1-negative patients with stage II–III tumors who received systematic adjuvant chemotherapy was higher compared with ERCC1-negative patients. The 3-year DFS and OS rates for ERCC1-negative patients with squamous carcinoma were higher compared with ERCC1-positive patients. In addition, p38 inhibitor treatment significantly inhibited the mRNA and protein expression levels of ERCC1 in A549 cells, and enhanced the sensitivity of cells to cisplatin. The results of the present study suggest that ERCC1 expression is an important prognostic indicator for NSCLC, particularly for patients with stage II–III tumors who receive systematic platinum-based adjuvant chemotherapy.

Randomized Prospective Biomarker Trial of ERCC1 for Comparing Platinum and Nonplatinum Therapy in Advanced Non-Small-Cell Lung Cancer: ERCC1 Trial (ET)

Purpose Retrospective studies indicate that expression of excision repair cross complementing group 1 (ERCC1) protein is associated with platinum resistance and survival in non-small-cell lung cancer (NSCLC). We conducted the first randomized trial, to our knowledge, to evaluate ERCC1 prospectively and to assess the superiority of nonplatinum therapy over platinum doublet therapy for ERCC1-positive NSCLC as well as noninferiority for ERCC1-negative NSCLC. Patients and Methods This trial had a marker-by-treatment interaction phase III design, with ERCC1 (8F1 antibody) status as a randomization stratification factor. Chemonaïve patients with NSCLC (stage IIIB and IV) were eligible. Patients with squamous histology were randomly assigned to cisplatin and gemcitabine or paclitaxel and gemcitabine; nonsquamous patients received cisplatin and pemetrexed or paclitaxel and pemetrexed. Primary end point was overall survival (OS). We also evaluated an antibody specific for XPF (clone 3F2). The target hazard ratio (HR) for patients with ERCC1-positive NSCLC was ≤ 0.78. Results Of patients, 648 were recruited (177 squamous, 471 nonsquamous). ERCC1-positive rates were 54.5% and 76.7% in nonsquamous and squamous patients, respectively, and the corresponding XPF-positive rates were 70.5% and 68.5%. Accrual stopped early in 2012 for squamous patients because OS for nonplatinum therapy was inferior to platinum therapy (median OS, 7.6 months [paclitaxel and gemcitabine] v 10.7 months [cisplatin and gemcitabine]; HR, 1.46; P = .02). Accrual for nonsquamous patients halted in 2013. Median OS was 8.0 (paclitaxel and pemetrexed) versus 9.6 (cisplatin and pemetrexed) months for ERCC1-positive patients (HR, 1.11; 95% CI, 0.85 to 1.44), and 10.3 (paclitaxel and pemetrexed) versus 11.6 (cisplatin and pemetrexed) months for ERCC1-negative patients (HR, 0.99; 95% CI, 0.73 to 1.33; interaction P = .64). OS HR was 1.09 (95% CI, 0.83 to 1.44) for XPF-positive patients, and 1.39 (95% CI, 0.90 to 2.15) for XPF-negative patients (interaction P = .35). Neither ERCC1 nor XPF were prognostic: among nonsquamous patients, OS HRs for positive versus negative were ERCC1, 1.11 ( P = .32), and XPF, 1.08 ( P = .55). Conclusion Superior outcomes were observed for patients with squamous histology who received platinum therapy compared with nonplatinum chemotherapy; however, selecting chemotherapy by using commercially available ERCC1 or XPF antibodies did not confer any extra survival benefit.

Evaluating the Prognostic Value of ERCC1 and Thymidylate Synthase Expression and the Epidermal Growth Factor Receptor Mutation Status in Adenocarcinoma Non-Small-Cell Lung Cancer

The present study evaluated the prognostic value of the epidermal growth factor receptor (EGFR) mutation status, and excision repair cross-complementation group 1 (ERCC1) and thymidylate synthase (TS) expression following intercalated tyrosine kinase inhibitor (TKI) therapy and platinum- and pemetrexed-based chemotherapies (subsequent second-line treatment) for patients with adenocarcinoma non-small-cell lung cancer (AC-NSCLC). In total, 131 patients with AC-NSCLC were enrolled. The EGFR mutation status and ERCC1 and TS expression were evaluated through direct DNA sequencing and immunohistochemical analyses, respectively. The EGFR mutation status and ERCC1 and TS expression were the significant predictors of clinical outcomes. The EGFR mutation status was the main outcome predictor for overall survival (OS) benefits in the overall population. Further exploratory ERCC1 and TS expression analyses were conducted to provide additional insights. Low TS expression was predictive of improved OS of patients with negative EGFR-mutated advanced AC-NSCLC, whereas high ERCC1 expression resulted in poor OS in patients with positive EGFR-mutated advanced AC-NSCLC. TS and ERCC1 expression levels were effective prognostic factors for negative and positive EGFR-mutated AC-NSCLC, respectively. In conclusion, the present results indicate that the EGFR mutation status and TS and ERCC1 expression can be used as the predictors of OS after subsequent second-line treatments for AC-NSCLC.

Clinicopathological and immunohistochemical features of lung invasive mucinous adenocarcinoma based on computed tomography findings

Background

We performed an analysis to clarify differences in clinicopathological and molecular features of lung invasive mucinous adenocarcinoma (IMA) based on computed tomography (CT) findings and their impact on prognosis.

Patients and methods

On the basis of CT findings, we divided lung IMA into three subtypes: solid, bubbling, and pneumonic. We then investigated differences in clinicopathological characteristics, prognosis, and the expressions of well-identified biomarkers, including cyclooxygenase-2 (Cox-2), excision repair cross-complementation group 1 (ERCC1), ribonucleotide reductase M1 (RRM1), class III beta-tubulin, thymidylate synthase (TS), secreted protein acidic and rich in cysteine (SPARC), programmed cell death-1 ligand-1 (PD-L1), and epidermal growth factor receptor mutation, among the three subtypes.

Results

A total of 29 patients with resected lung IMA were analyzed. Compared with the solid or bubbling type, the pneumonic type had a higher proportion of symptoms, a larger tumor size, a higher pathological stage, and a significantly worse prognosis. The immunohistochemical findings tended to show high expression of RRM1, class III beta-tubulin, and Cox-2 in the tumor and of SPARC in the stroma, but not of ERCC1, TS, and PD-L1 in the tumor. None of the biomarkers with high expression levels in the tumor were prognostic biomarkers, but the expression of SPARC in the stroma was correlated with a poor outcome.

Conclusion

Clinical and pathological features, in conjunction with molecular data, indicate that IMA should be divided into different subgroups. In our results, the pneumonic type was correlated with a significantly worse outcome. Further studies should be performed to confirm our conclusion and to explore its molecular implications.

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.