Despite often leading to platinum resistance, platinum-based chemotherapy continues to be the standard treatment for many epithelial tumors. In this study we analyzed and validated the cytogenetic alterations that arise after treatment in four lung and ovarian paired cisplatin-sensitive/resistant cell lines by 1-million microarray-based comparative genomic hybridization (array-CGH) and qRT-PCR methodologies. RNA-sequencing, functional transfection assays, and gene-pathway activity analysis were used to identify genes with a potential role in the development of this malignancy. The results were further explored in 55 lung and ovarian primary tumors and control samples, and in two extensive in silico databases. Long-term cell exposure to platinum induces the frequent deletion of ITF2 gene. Its expression re-sensitized tumor cells to platinum and recovered the levels of Wnt/β-catenin transcriptional activity. ITF2 expression was also frequently downregulated in epithelial tumors, predicting a worse overall survival. We also identified an inverse correlation between ITF2 and HOXD9 expression, revealing that Non-small cell lung cancer (NSCLC) patients with lower expression of HOXD9 had a better overall survival rate. We defined the implication of ITF2 as a molecular mechanism behind the development of cisplatin resistance probably through the activation of the Wnt-signaling pathway. This data highlights the possible role of ITF2 and HOXD9 as novel therapeutic targets for platinum resistant tumors.

Despite advances in non-small cell lung cancer (NSCLC) research, this is still the most common cancer type that has been diagnosed up to date. microRNAs have emerged as useful clinical biomarkers in both tissue and liquid biopsy. However, there are no reliable predictive biomarkers for clinical use. We evaluated the preclinical use of seven candidate miRNAs previously identified by our group. We collected a total of 120 prospective samples from 88 NSCLC patients. miRNA levels were analyzed via qRT-PCR from tissue and blood samples. miR-124 gene target prediction was performed using RNA sequencing data from our group and interrogating data from 2952 NSCLC patients from two public databases. We found higher levels of all seven miRNAs in tissue compared to plasma samples, except for miR-124. Our findings indicate that levels of miR-124, both free-circulating and within exosomes, are increased throughout the progression of the disease, suggesting its potential as a marker of disease progression in both advanced and early stages. Our bioinformatics approach identified KPNA4 and SPOCK1 as potential miR-124 targets in NSCLC. miR-124 levels can be used to identify early-stage NSCLC patients at higher risk of relapse.

Non-small-cell lung cancer (NSCLC) is the most common malignancy worldwide. Platinum-based chemotherapy is the standard of care for these patients. Recent research showed that miR-7 methylation status is a biomarker of cisplatin resistance in lung and ovarian cancer cells, which is one of the major limitations associated with their clinical management. The aim of the present study is to provide clinical insights associated with this novel potential biomarker in NSCLC patients by comparing the miR-7 methylation status with the cisplatin treatment response. Our results analyzed in 81 samples show that miR-7 methylation is a common event in tumor tissue and it is more frequent as the stage of the disease advances, remaining in 75% of metastatic patients. Tumor miR-7 unmethylation trend to a better PFS in early stages, and when our data was validated in an extended “in silico” cohort of 969 patients we obtained a significant increment in PFS and OS in those patients harboring miR-7 unmethylated (p = 0.010 and p = 0.007 respectively). When we select those early-stages patients harbouring miR-7 methylation, we observed that adenocarcinoma patients present a dramatic decrease in PFS compared with squamous cell carcinoma patients (median 18.9 versus 59.7 months, p = 0.002). In conclusion, our results show that presence of miR-7 methylation in early-stage NSCLC is suggestive of aggressive behavior, especially for adenocarcinoma patients. One major challenge in early diagnosis in NSCLC is identify the subgroup of patients that could benefit for adjuvant therapy, our data establish the basis for epigenetic classification on early-stage NSCLC that could influence treatment decisions in the future.

Platin-based chemotherapy is the standard treatment for patients with non-small cell lung cancer (NSCLC). However, resistance to this therapy is a major obstacle in successful treatment. In this study, we aimed to investigate the impact of several pharmacogenetic variants in patients with unresectable NSCLC treated with platin-based chemotherapy. Our results showed that DPYD variant carriers had significantly shorter progression-free survival and overall survival compared to DPYD wild-type patients, whereas DPD deficiency was not associated with a higher incidence of high-grade toxicity. For the first time, our study provides evidence that DPYD gene variants are associated with resistance to platin-based chemotherapy in NSCLC patients. Although further studies are needed to confirm these findings and explore the underlying mechanisms of this association, our results suggest that genetic testing of DPYD variants may be useful for identifying patients at a higher risk of platin-based chemotherapy resistance and might be helpful in guiding future personalized treatment strategies in NSCLC patients.

Purpose: Many cancers initially respond to Cisplatin-based chemotherapy; however, resistance frequently develops. We have recently reported that reduction of IGFBP-3 expression by promoter methylation is involved in the CDDP acquired resistance process in 3 matched CDDP sensitive/resistant human cancer cell lines and in a human cohort of 36 in non-small cell lung cancer (NSCLC) patients, probably because CDDP also induces DNA methylation de novo. The purpose of the present study is to investigate the role of IGFBP-3 in the PI3K signaling pathway alterations to design a translational based-profile to predict resistance in NSCLC. The biological significance of IGFBP-3 is of great importance in controlling cell growth, transformation and survival; as IGF-I binds to IGFBP-3 with stronger affinity than to its own receptor (IGFIR), blocking their interaction and abolishing the mitogenic and antiapoptotic actions. IGF-I is also able to activate EGF receptor. Those tyrosine kinases receptors (IGFIR and EGFR), signal through the PI3K/Akt pathway, that plays a crucial role in cell growth, proliferation, and survival and is commonly upregulated during tumorigenesis, including NSCLC; although the precise mechanism is not well defined. Patients and methods: In the present study we have examined the relationship between first, IGFBP-3 gene expression regulated by promoter methylation measured by RT-PCR, bisulfite sequencing and methylation specific PCR and second the activation of the EGFR, IGFIR and PI3K/AKT pathways through the analysis of the PTEN, AKT, pAKT, pEGFR, EGFR, pIGFIR and IGFIR protein levels by Western-Blot, immunofluorescence and immunohistochemical analysis in 10 human cancer cell lines and in 25 NSCLC patients with known IGFBP-3 methylation status and response to CDDP. Additionally, in order to provide a helpful tool that enables clinicians to identify or to exclude patients with a potential response to cisplatin, we have used the Fisher's exact test within a 2x2 contingence table to calculate the association between our diagnostic test and the true outcome of analyzed samples in terms of cisplatin IC50. Results: Our results suggest that loss of IGFBP-3 expression by promoter methylation in tumor cells treated with CDDP may activate the PI3K/AKT pathway through the specific derepression of IGFIR signaling, inducing resistance to CDDP. This study also provides a predictive test for clinical practice with an accuracy and precision of 0.84 and 0.9, respectively, (P=0.0062). Conclusion: We present a biomarker-test that could provide clinicians with a robust tool with which to decide on the use of cisplatin, improving patient clinical outcomes. Supported by FIS project number: PS09/00472 and a Miguel Servet financial grant to Ibanez de Caceres, I (CP08/000689; PI-717). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1726. doi:1538-7445.AM2012-1726

Despite advancements in personalized cancer therapies, platinum-based chemotherapy remains the cornerstone for treating solid tumors, including Non-Small Cell Lung Cancer (NSCLC). The integration of novel immunotherapies with platinum compounds has shown promising outcomes for the treatment of advanced disease. However, a significant proportion of patients experience therapeutic failure due to innate or acquired resistance. Thus, identifying molecular profiles and biomarkers to monitor patient progress and treatment response is crucial for tailoring therapeutic strategies. Small extracellular vesicle (sEV)-based liquid biopsy emerges as a promising non-invasive method for cancer management. sEVs play a critical role in cell communication and provide molecular insights into the tumor environment. In this study, we characterized the microRNome content of sEVs from cisplatin-resistant and -sensitive cancer cells using small-RNA sequencing. We identified and validated three miRNAs in two cohorts of 78 and 49 patients treated with either chemotherapy alone or chemo-immunotherapy, respectively, analyzed via liquid biopsy, differentiating NSCLC patients based on progression and overall survival. Notably, miR-451a emerged as a prognostic marker for chemo and chemo-immunotherapy, while miR-142-3p was identified for the first time as a potential prognostic marker specifically for stage IV patients, irrespective of the treatment. The combination of miR-451, miR-142-3p, and miR-55745, a novel miRNA identified from our miRNome screening, serves as a valuable biomarker for both cisplatin and chemo-immunotherapy treatment responses. This study underscores the role of sEVs in acquired cisplatin resistance and introduces novel miRNA-sEV biomarkers for managing NSCLC progression.