ERCC1 and the efficacy of cisplatin in patients with resected non-small cell lung cancer

SET and MYND domain-containing protein 3 inhibits tumor cell sensitivity to cisplatin

Cisplatin resistance has been a major factor limiting its clinical use as a chemotherapy drug. The present study aimed to investigate whether SET and MYND domain-containing protein 3 (SMYD3), a histone methyltransferase closely associated with tumors can affect the sensitivity of tumors to cisplatin chemotherapy. Real time-qPCR, western blotting, the luciferase reporter, MTT and clonogenic assays were performed to detect the effects of SMYD3 on the chemotherapy capacity of cisplatin. In the present study, SMYD3 exhibited different expression patterns in MCF-7 and T47D breast cancer cells. In addition, this differential expression was associated with tumor cell resistance to cisplatin. Furthermore, SMYD3 knockdown following small interfering RNA transfection increased cisplatin sensitivity, whereas SMYD3 overexpression decreased cisplatin sensitivity. In addition, SMYD3 knockdown synergistically enhanced cisplatin-induced cell apoptosis. SMYD3 expression was downregulated during cisplatin treatment. In addition, transcriptional regulatory activities of SMYD3 3'-untranslated region were also downregulated. These results suggested that SMYD3 may affect cell sensitivity to cisplatin and participate in the development of cisplatin resistance, which is a process that may involve microRNA-124-mediated regulation.

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.

Enhanced antitumor efficacy of cisplatin for treating ovarian cancer in vitro and in vivo via transferrin binding

Cisplatin is a widely used anticancer drug, while non-targeted delivery, development of drug resistance, and serious side effects significantly limit its clinical use. In order to improve the tumor-targeting properties of cisplatin, transferrin (Tf) was employed as a carrier to transfer cisplatin into cancer cells via transferrin receptor 1 (TfR1) mediated endocytosis. The binding ability of cisplatin and Tf could be improved by pretreating Tf with 10% ethanol, and the binding number of cisplatin for each Tf molecule could reach to 40 without structural or functional impairment of Tf. The Tf-cisplatin complex could be delivered into human ovarian carcinoma cells high efficiently. In tumor-bearing nude-mice model, the Tf-cisplatin complex inhibited tumor growth in vivo more effectively than free cisplatin, with less toxicity in other tissues. Tumor targeting efficiency of the Tf-cisplatin complex was supported by in vivo and ex vivo imaging and platinum residues detected in each ex vivo organ. These data suggested that Tf-cisplatin  was more effective and less drug-resistance than cisplatin, with targeting to tumor cells. Therefore, Tf-mediated delivery of cisplatin is a potential strategy for targeted delivery into tumor cells.

ERCC1_202 Is A Prognostic Biomarker in Advanced Stage Non-Small Cell Lung Cancer Patients Treated with Platinum-Based Chemotherapy

Purpose: To develop a qPCR method to examine the 202 isoform of excision repair cross-complementation group 1 (ERCC1_202) and to evaluate its clinical utility as a predictive biomarker for platinum-based chemotherapy in non-small cell lung cancer (NSCLC). Methods: The relative complementary DNA (cDNA) quantification for ERCC1_202 was conducted using a fluorescence-based, real-time detection method and β-actin was used as a reference gene. Results: A strong correlation was observed between ERCC1_202 mRNA and ERCC1 mRNA levels in NSCLC cells (P < 0.001). 28 patients completed this research. Our results implied that as ERCC1_202 levels increased, the risk of progression (HR = 4.296, P = 0.011) and death (HR = 6.503, P = 0.001) increased. At multivariate analysis, high expression of ERCC1_202 was shown to be an independent predictive factor for time to progression (P = 0.047), and progression-free survival (P = 0.014). However, the high expression of ERCC1_202 was not an independent predictive factor for response (P = 0.324). Conclusions: This study suggests that the efficacy of platinum-based chemotherapy can be improved when customized according to the expression of ERCC1_202.

18F-fludrodeoxyglucose maximal standardized uptake value and metabolic tumor burden are associated with major chemotherapy-related tumor markers in NSCLC patients

Objective

Metabolic activity and tumor burden are significant for prognosis and metastasis of non-small cell lung cancer (NSCLC), including maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Chemotherapy resistance is a great challenge for treating NSCLC patients and is also closely related with several biomarkers such as epidermal growth factor receptor (EGFR), p53, and excision repair cross-complementing group 1 protein (ERCC1). Our purpose was to determine the correlation between positron emission tomography/computed tomography (PET/CT) parameters and tumor markers-related chemotherapy resistance in NSCLC.

Methods

Forty-six NSCLC chemotherapy-naïve patients were enrolled. The SUV_max, MTV, and TLG were calculated by PET/CT imaging, and expression of EGFR, p53, and ERCC1 were analyzed by immunohistochemistry on tissues. SUV_max, MTV, and TLG compared for their performance in predicting the expression of EGFR, p53, and ERCC1 were illustrated with statistical analysis.

Results

SUV_max was significantly correlated with p53 expression (P=0.001), and MTV and TLG were significantly associated with ERCC1 (P=0.000; P=0.000). Furthermore, multiple stepwise regression analysis revealed that SUV_max was the primary predictor for p53, MTV and TLG was the primary predictor for ERCC1. SUV_max had a sensitivity of 91% and specificity of 50% for the detection of p53 positive. The sensitivities of MTV and TLG were 83% and 80%, and specificities were 69% and 75% for the detection of ERCC1 positive, respectively. When we suggested p53 or ERCC1 positive, the cutoff value of SUV_max, MTV, and TLG were 7.68, 23.62, and 129.65 cm³, respectively.

Conclusion

SUV_max, MTV, and TLG were closely associated with p53 and ERCC1’ expressions. Therefore, ¹⁸F-fludrodeoxyglucose PET/CT could be a new way of predicting p53 or ERCC1-related chemotherapy effect in NSCLC patients with more convenience.

Influence on radiosensitivity of lung glandular cancer cells when ERCC1 gene silenced by targeted siRNA

OBJECTIVE

To identify the influence on radiosensitivity of lung glandular cancer cells when excisions repair cross-complementing group1 (ERCC1) gene was silenced by targeted siRNA.

METHODS

siRNA which targeting to ERCC1 and control siRNA was designed and synthesized. The human lung glandular cancer SPC-A-1 cells was transfected. A total of 56 nude mice were divided into two groups, and two kinds of SPC-A-1 cells were transplanted to armpit of right forelimb, to establish the nude mice subcutaneous xenotransplanted tumor model of human lung glandular cancer cells. After the tumor was developed, the nude mice were randomly divided into four groups and accepted different doses of X-Ray radiation, then the change of tumor volume, survival time of mice in every group were recorded and the average lifetime was calculated. Twenty-one days later of X-ray experiment, two mice were taken and killed in each group and the tumors organizations were stripped. The cell apoptosis rate and cell cycle distributions were obtained by FCM (flow cytometry).

RESULTS

The volume of tumor which ERCC1 gene was silenced was less than single irradiation group after X-ray irradiation, and the growth speed was slower and the lifetime of mice was lengthened as well (P < 0.05). The cells apoptosis rate and the rate of G2/M cells which ERCC1 gene was silenced were higher than the same dose control group and the rate of G1 cells were lower, which indicated that the cells could be stopped at G2/M point, the cell proliferation was inhibited, the cell apoptosis was promoted and the radiation sensitivity was improved after the ERCC1 was silenced.

CONCLUSIONS

The radiation sensitivity of lung glandular tumor could be improved after the ERCC1 gene was silenced by siRNA.

Cisplatin resistance and opportunities for precision medicine

Cisplatin is one of the most commonly used chemotherapy drugs, treating a wide range of cancer types. Unfortunately, many cancers initially respond to platinum treatment but when the tumor returns, drug resistance frequently occurs. Resistance to cisplatin is attributed to three molecular mechanisms: increased DNA repair, altered cellular accumulation, and increased drug inactivation. The use of precision medicine to make informed decisions on a patient's cisplatin resistance status and predicting the tumor response would allow the clinician to tailor the chemotherapy program based on the biology of the disease. In this review, key biomarkers of each molecular mechanism will be discussed along with the current clinical research. Additionally, known polymorphisms for each biomarker will be discussed in relation to their influence on cisplatin resistance.