Sunitinib is one of the most widely used targeted therapeutics for renal cell-cancer (RCC) but acquired resistance against targeted therapies remains a major clinical challenge. To dissect mechanisms of acquired resistance and unravel reliable predictive biomarkers for sunitinib in renal cell-cancer (RCC), we sequenced the exons of 409 tumor-suppressor genes and oncogenes in paired tumor samples from an RCC patient, obtained at baseline and following development of acquired resistance to sunitinib. From newly arising mutations, we selected, using in-silico prediction models, 6 predicted to be deleterious, located in G6PD, LRP1B, SETD2, TET2, SYNE1 and DCC. Consistently, immunoblotting analysis of lysates derived from sunitinib-desensitized RCC cells and their parental counterparts showed marked differences in the levels and expression pattern of the proteins encoded by these genes. Our further analysis demonstrates essential roles for these proteins in mediating sunitinib cytotoxicity and shows that their loss of function render tumor cells resistant to sunitinib in vitro and in vivo. Finally, sunitinib resistance induced by continuous exposure or by inhibition of the 6 proteins was overcome by treatment with cabozantinib or a low-dose combination of lenvatinib and everolimus. Collectively, our results unravel novel markers of acquired resistance to sunitinib and clinically relevant approaches for overcoming this resistance in RCC.

Background and objectives: there are few published data on the use of EUS guided fine-needle aspiration in secondary pancreatic lesions. We describe the largest series published so far in a European country. Patients and methods: a retrospective review of the cases identified in our institution from 2004 to 2016 has been recorded. The clinical data are described, comparing the latency period from the primary tumor diagnosis to the detection of the pancreatic metastasis and the survival of patients according to the cytological diagnosis. Results: forty-four patients were diagnosed with pancreatic metastasis using EUS guided fine needle aspiration. Ancillary cytological studies were performed in 28 (63.6%). The most common primary tumor sites were kidney and lung. Thirty-four patients (77.3%) had a previous history of malignancy, with a latency period ranging from 6 months to 18.8 years. Patients diagnosed with primary renal carcinoma had a significantly longer latency period and longer survival compared to those with primary lung cancer. In 13 patients, EUS was either the only technique that detected the PM or showed a greater number of intrapancreatic lesions. These metastases were significantly smaller than those diagnosed by other imaging studies (11.9 +/- 4.1 mm vs 30.7 +/- 19.8 mm, p < 0.001). Conclusions: EUS guided fine-needle aspiration plays a crucial role in the diagnosis of pancreatic metastases and may have a major clinical impact. Patients with renal cell carcinoma could benefit from long-term follow-up with EUS.

Background Programmed death-ligand 1 (PD-L1) expression, as assessed by immunohistochemistry (IHC), is used to select patients with non-small cell lung cancer (NSCLC) for anti-programmed cell death protein 1 (PD-1)/PD-L1 therapy. The current study evaluated the feasibility and efficacy of PD-L1 immunostaining and quantitation on direct Papanicolaou-stained cytological smears compared with formalin-fixed paraffin-embedded samples (cytological cell blocks and surgical resection specimens) in NSCLC cases using 2 commercially available assays: the PD-L1 IHC 22C3 pharmDx assay (Agilent Technologies/Dako, Carpinteria, CA, USA) and the Ventana SP263 Assay (Ventana Medical Systems Inc, Tucson, Arizona). Methods PD-L1 immunostaining using either both or one of the assays was tested in 117 sets of paired samples obtained from 62 NSCLC cases. The tumor proportion score was reported in every case following the recommendations of the International Association for the Study of Lung Cancer (IASLC). Results In 57 sets of samples, both PD-L1 assays were used. Due to the availability of samples, only 1 assay was performed in 3 sets of samples and in 2 cases, only cytology smears were used and tested for both assays. A total of 113 sets of paired samples finally were evaluated; 4 cases could not be studied due to intense nonspecific background staining. A significant concordance between the 2 assays on cytological smears was found. Concordance between paired cytological smears and formalin-fixed paraffin-embedded samples was observed in 97.3% of the cases. Conclusions The quantification of PD-L1 expression on direct Papanicolaou-stained cytology smears is feasible and reliable for both PD-L1 assays.

CONTEXT: - The rapid advances in targeted therapies in non-small cell lung cancer (NSCLC) make the optimization and implementation of cytology specimens for molecular testing a priority. Up to 70% of patients with NSCLC are diagnosed at advanced stages and tissue biopsies often cannot be taken. Although cytology samples provide high-quality material for molecular testing, molecular cytopathology is not yet well known or widely used. OBJECTIVE: - To report the many advances in molecular cytopathology and the suitability and utility of cytology samples in molecular and genetic testing of NSCLC. DATA SOURCES: - Data sources comprised published peer-reviewed literature and personal experience of the authors. CONCLUSIONS: - Molecular testing can be performed on cytologic specimens, especially on direct smears. Rapid on-site evaluation by cytopathologists has improved the adequacy and the management of cytology samples for molecular testing. Mutational profiling of NSCLC using next-generation sequencing can be performed on cytology samples from very small amounts of DNA. Fluorescence in situ hybridization assays on cytology specimens, including stained direct smear, offer some distinct advantages over their histologic counterpart, and are used to detect ALK and ROS1 rearrangements in NSCLC. Cytology specimens allow assessment of the entire tumor cell nucleus, avoiding signal loss from truncation artifacts. The use of cytology samples for assessing programmed death ligand-1 protein expression is currently being developed. Protocols for bisulfite conversion and DNA droplet digital polymerase chain reaction assays have been optimized for cytology smear to investigate aberrant DNA methylation of several NSCLC-related genes

Background: TGF-beta has been described as a mediator of fibrosis and scarring. Several studies achieved reduction in experimental scarring through the inhibition of TGF-beta. Fibroblasts have been defined as the cell population originating fibrosis, blocking fibroblast invasion may impair epidural fibrosis appearance. For this purpose, biocompatible materials used as mechanical barriers and a TGF-beta inhibitor peptide were evaluated in the reduction of epidural fibrosis. Methods: A L6 laminectomy was performed in 40 New Zealand white rabbits. Divided into four groups, each rabbit was assigned to receive either collagen sponge scaffold (CS group), gelatin-based gel (GCP group), P144 (R) (iTGF beta group), or left untreated (control group). Four weeks after surgery, cell density, collagen content, and new bone formation of the scar area were determined by histomorphometry. Two experienced pathologists scored dura mater adhesion, scar density, and inflammatory infiltrate in a blinded manner. Results: In all groups, laminectomy site was filled with fibrous tissue and the dura mater presented adhesions. Only GCP group presented a significant reduction in collagen content and scar density. Conclusion: GCP treatment reduces epidural fibrosis although did not prevent dura mater adhesion completely.

Atezolizumab is an IgG1 isotype monoclonal antibody against the protein programmed cell death-ligand 1 (PD- L1). PD-L1 may be highly expressed in some tumors and is believed to inhibit immune cells that recognize and attack tumor cells. Inhibition of PD-L1 can remove its inhibitory effect and provoke an anti-tumor response. In October 2016, the Food and Drugs Administration (FDA) approved atezolizumab for the treatment of patients with metastatic non-small cell lung cancer after disease progression during or following platinum based chemotherapy. We present the case of a 43-year-old male with stage IV lung adenocarcinoma in progression, despite standard chemotherapy.

BACKGROUNDMolecular testing to determine gene mutation status is now the recommended standard of care for patients with advanced or metastatic Non-small cell lung cancer (NSCLC). Because the majority of patients with NSCLC present with metastatic disease, minimally invasive procedures are necessary for diagnosis, staging, and molecular analysis. However, the resulting samples have perceived limitations in the oncology community, and most commercially available tests have not been validated for these sample types. The current study was undertaken to assess the feasibility of determining epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation status in fine-needle aspirates (FNAs) and core-needle biopsies (CNBs) after staining with Papanicolaou or hematoxylin and eosin, respectively. METHODSGene mutation status was determined in 140 NSCLC tumor samples with proprietary tests for EGFR and KRAS mutations (cobas tests) followed by Sanger sequencing of exons 18 through 21 of the EGFR gene and exon 2 of the KRAS gene. The results were analyzed based on FNA (n=91) or CNB (n=49) sampling. RESULTSThe cobas tests yielded valid results in the majority of FNA and CNB samples for both EGFR (97.9%) and KRAS (93.6%). Moreover, valid results were obtained for 90% of samples that had DNA concentrations below the values recommended by the manufacturer. For samples with valid results from both cobas testing and Sanger sequencing, 95.7% and 93% agreement were observed for EGFR status and KRAS status, respectively. CONCLUSIONSGene mutation testing can be successfully performed on cytology and CNB samples, expanding the potential of personalized cancer treatment to patients who have limited tissue samples. Cancer (Cancer Cytopathol) 2015;123:230-236. (c) 2014 The Authors. Cancer Cytopathology published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. EGFR or KRAS mutation status can be successfully determined in Papanicolaou-stained fine-needle aspiration samples and hematoxylin and eosin-stained core-needle biopsy samples using polymerase chain reaction-based tests. The findings from this pilot study highlight the feasibility of rapid and accurate mutation testing for patient samples derived from minimally invasive diagnostic procedures or from samples with limited available tissue.

The experience in Spain's longest lung cancer screening program is comparable to what has been described in the rest of Europe, and confirms the feasibility and efficacy of lung cancer screening using LDCT.

CD137 (4-1BB) is a surface marker discovered on activated T lymphocytes. However, its expression pattern is broader and has also been described on activated NK cells, B-cells and myeloid cells including mature dendritic cells. In this study, we have immunostained for CD137 on paraffin-embedded lymphoid tissues including tonsils, lymph nodes, ectopic tertiary lymphoid tissue in Hashimoto thyroiditis and cancer. Surprisingly, immunostaining mainly decorates intrafollicular lymphocytes in the tissues analyzed, with only scattered staining in interfollicular areas. Moreover, pathologic lymphoid follicles in follicular lymphoma and tertiary lymphoid tissue associated to non-small cell lung cancer showed a similar pattern of immunostaining. Multicolor flow cytometry demonstrated that CD137 expression was restricted to CD4+ CXCR5+ follicular T helper lymphocytes in tonsils and lymph nodes. Short term culture of lymph node cell suspensions in the presence of an agonist anti-CD137 mAb or CD137-ligand results in the functional upregulation of TFH cells, including CD40L surface expression and cytokine production, in three out of six cases. As a consequence, immunostimulatory monoclonal antibodies, anti-CD137 mAb such as urelumab and PF-05082566 should be expected to primarily act on this lymphocyte subset, thus modifying ongoing humoral immune responses.

Objectives: Liver metastases appear in 20-30% of patients diagnosed with non-small cell lung cancer (NSCLC) and represent a poor prognosis feature of NSCLC and a possibly more treatment-resistant condition. Potential clinical outcome differences in NSCLC patients with liver metastases harboring molecular alterations in EGFR, KRAS and EML4-ALK genes are still to be determined. This study aims to evaluate the incidence of liver metastasis in a single population and look for potential correlations between EGFR mutations, liver infiltration and clinical outcomes. Methods: A total of 236 consecutive stage IV NSCLC patients treated at the Clinica Universidad de Navarra were analyzed. Results: At onset, liver metastases were present in 16.9% of patients conferring them a shorter overall survival (OS) compared to those with different metastatic locations excluding liver infiltration (10 vs. 21 months; p = 0.001). Patients with EGFR wild-type tumors receiving standard chemotherapy and showing no liver involvement presented a superior median OS compared to those with liver metastases (23 vs. 13 months; p = 0.001). Conversely, patients with EGFR-mutated tumors treated with EGFR tyrosin-kinase inhibitors (TKI's) presented no significant differences in OS regardless of liver involvement (median OS not reached vs. 25 months; p = 0.81). Conclusion: Overall, liver metastases at onset negatively impact OS of NSCLC patients. EGFR TKIs however, may reverse the effects of an initial negative prognosis of liver metastasis in first-line treatment of EGFR mutated NSCLC patients.

Background: Mortality in early stage, resectable lung cancer is sufficiently high to warrant consideration of post-surgical treatment. Novel markers to stratify resectable lung cancer patients may help with the selection of treatment to improve outcome. Methods: Primary tumour tissue from 485 patients, surgically treated for stage I-II lung adenocarcinoma, was analysed for the RNA expression of 31 cell cycle progression (CCP) genes by quantitative polymerase chain reaction (PCR). The expression average, the CCP score, was combined with pathological stage into a prognostic score (PS). Cox proportional hazards regression assessed prediction of 5-year lung cancer mortality above clinical variables. The PS threshold was tested for risk discrimination by the Mantel-Cox log-rank test. Results: The CCP score added significant information above clinical markers (all patients, P = 0.0029; stage I patients, P = 0.013). The prognostic score was a superior predictor of outcome compared to pathological stage alone (PS, P = 0.00084; stage, P = 0.24). Five-year lung cancer mortality was significantly different between the low-risk (90%, 95% confidence interval (CI) 81-95%), and high-risk groups (65%, 95% CI 57-72%), P = 4.2 x 10(-6)). Conclusions: The CCP score is an independent prognostic marker in early stage lung adenocarcinoma. The prognostic score provides superior risk estimates than stage alone. The threefold higher risk in the high-risk group defines a subset of patients that should consider therapeutic choices to improve outcome.

As a result of therapeutic advances, a revolution is taking place in the lung cancer field with major implications for pathologic diagnosis and tissue management. We report a case of a non-small cell lung carcinoma patient with coexistence of EGFR mutations and ALK-EML4 rearrangements that responded to EGFR inhibitors and in which the development of a new resistance mutation in exon 20 of EGFR-determined treatment resistance. All the molecular determinations were performed in cytological samples. To our knowledge, this is the first case reported with these characteristics, and the 11th case described with coexistence of EGFR mutations and ALK-EML4 rearrangements. The EGFR L858R mutation in exon 21 was found at diagnosis, and the patient presented a 4-year response to erlotinib. On progression, the T790M resistance mutation in the EGFR exon 20 was also confirmed in cytological samples. At this point, fluorescence in situ hybridization also detected ALK-EML4 translocation. This case emphasizes the usefulness of cytological samples for molecular analysis in lung adenocarcinoma, as well as the relevance of repeating biopsies/fine-needle aspirations in tumor recurrences to assess the mutation profile of the disease.

AIMS: Glioblastomas display marked phenotypic and molecular heterogeneity. The expression of the PTEN protein in glioblastomas also shows great intratumour heterogeneity, but the significance of this heterogeneity has so far received little attention. METHODS: We conducted a comparative study on paraffin and frozen samples from 60 glioblastomas. Based on PTEN immunostaining, paraffin glioblastomas were divided into positive (homogeneous staining) and both positive and negative (heterogeneous staining) tumours. DNA was extracted from manually microdissected samples from representative areas, and from frozen samples taken randomly from the same tumours. Loss of heterozygosity (LOH) of 10q23 and hypermethylation status of the PTEN promoter were studied, and the molecular findings were correlated with overall survival. RESULTS: PTEN protein was present heterogeneously in 42 cases and homogeneously in 18 cases. In homogeneous glioblastomas, no correlation was found between PTEN protein expression and the LOH of the gene. Surprisingly, in the heterogeneous glioblastomas, LOH was found significantly more frequently (P < 0.001) in PTEN-positive areas (81%) than in PTEN-negative ones (35.7%). In general, molecular results of frozen tissue were representative of the tumour. Only two cases of methylation of the PTEN promoter were identified. A significant difference was found for overall survival for LOH10q23 status (P = 0.005) and for homogeneous vs. heterogeneous tumours (P = 0.014). CONCLUSION: The expression of PTEN protein does not correlate with the abnormalities of the LOH of the gene. Interestingly, patients with glioblastomas presenting either LOH of 10q23 or heterogeneous PTEN expression have a poorer prognosis.

BRAF V600 mutation has been reported in more than 50% of melanoma cases and its presence predicts clinical activity of BRAF inhibitors (iBRAF). We evaluated the rote of MIA, S100 and LDH to monitor iBRAF efficiency in advanced melanoma patients presenting BRAF V600 mutations. This was a prospective study of melanoma patients harboring the BRAF V600 mutation and treated with iBRAF within a clinical trial (dabrafenib) or as part of an expanded access program (vemurafenib). MIA, S100 and LDH were analyzed in serum at baseline, and every 4-6 weeks during treatment. Eighteen patients with melanoma stages IIIc-IV were enrolled with 88.8% of response rate to iBRAF. Baseline concentrations of all the tumor markers correlated with tumor burden. MIA and S100 concentrations decreased significantly one month after the beginning of treatment and, upon progression, their concentrations increased significantly above the minimum levels previously achieved. MIA levels lower than 9 mu g/L one month after the beginning of treatment and S100 concentrations lower than 0.1 mu g/L at the moment of best response were associated With improved progression-free survival. In conclusion, MIA and S100 are useful to monitor response in melanoma patients treated with iBRAF.

Background: 2D7 and BB1 are thought to be basophil-specific markers. In this study, we tested both antibodies in different skin and mast cell disorders with the aim of determining whether it was possible to differentiate between benign and aggressive presentations of mastocytosis. Methods: Using the antibodies 2D7, BB 1, and c-Kit, we performed an immunohistochemical study of skin biopsy specimens from patients with cutaneous mastocytosis (15 urticaria pigmentosa and telangiectatic macularis eruptive perstans) and liver or bone marrow biopsy specimens from patients with systemic mastocytosis. A basophil leukemia cell line was used as a reference. Peripheral blood basophils from healthy donors were used as controls. Results: We observed intense expression of 2D7 and BB1 in all skin biopsy specimens from patients with cutaneous mastocytosis. Immunostaining of liver and bone marrow specimens from patients with systemic mastocytosis with 2D7 and BB1 antibodies was negative. Specimens from patients with either type of mastocytosis showed similarly strong expression of c-Kit. The basophil cell line showed a 2D7 and a BB1 profile, with intense expression of c-Kit. Peripheral blood basophils exhibited notable immunostaining for 2D7, BB1, and c-Kit. Conclusions: 2D7 and BB1 are expressed in cutaneous mastocytosis, although this expression is lost when mast cell proliferation is systemic, thus reflecting either a different cellular differentiation stage or the presence of basophils in these skin diseases.

The nonclassical human leukocyte antigen-G (HLA-G) is a tolerogenic molecule that can be released to the circulation by expressing cells. This molecule can form dimers but some other complexed HLA-G forms have been proposed to be present in vivo. Here, we further characterized these other complexed HLA-G forms in vivo. Ascitic and pleural exudates from patients were selected based on positivity for HLA-G by ELISA. Complexed HLA-G was detected in exosomes, which indicates an intracellular origin of these forms. 2D-PAGE analysis of exudates and isolated exosomes showed that these high molecular weight complexes were more heterogeneous than the HLA-G1 expressed by cell cultures. Treatment with deglycosylating enzymes did not change the molecular weight of HLA-G complexes. Immunoblot analysis of exudates and exosomes with an anti-ubiquitin antibody showed that at least some of these structures correspond to ubiquitinated HLA-G. HLA-G ubiquitination could be reproduced in vitro in HLA-G1-transfected cell lines, although with a lower modified/nonmodified protein proportion than in exudates. In summary, we demonstrate new circulating HLA-G forms in vivo that open a new perspective in the study of HLA-G function and analysis

The mutation status was identical in patients who had both biopsies and cytological samples analyzed. Conclusion. Assessment of EGFR and K-ras mutations in cytological samples is feasible and comparable with biopsy results, making individualized treatment

Objective. Epidermal growth factor receptor (EGFR) and K-ras mutations guide treatment selection in non-small cell lung cancer (NSCLC) patients. Although mutation status is routinely assessed in biopsies, cytological specimens are frequently the only samples available. We determined EGFR and K-ras mutations in cytological samples. Methods. DNA was extracted from 150 consecutive samples, including 120 Papanicolau smears (80%), 10 cell blocks (7%), nine fresh samples (6%), six ThinPrep(R) tests (4%), and five body cavity fluids (3.3%). Papanicolau smears were analyzed when they had > 50% malignant cells. Polymerase chain reaction and direct sequencing of exons 18-21 of EGFR and exon 2 of K-ras were performed. EGFR mutations were simultaneously determined in biopsies and cytological samples from 20 patients. Activity of EGFR tyrosine kinase inhibitors (TKIs) was assessed. Results. The cytological diagnosis was adenocarcinoma in 110 samples (73%) and nonadenocarcinoma in 40 (27%) samples. EGFR mutations were identified in 26 samples (17%) and K-ras mutations were identified in 18 (12%) samples. EGFR and K-ras mutations were mutually exclusive. In EGFR-mutated cases, DNA was obtained from stained smears in 24 cases (92%), pleural fluid in one case (4%), and cell block in one case (4%). The response rate to EGFR TKIs in patients harboring mutations was 75%. The mutation status was identical in patients who had both biopsies and cytological samples analyzed. Conclusion. Assessment of EGFR and K-ras mutations in cytological samples is feasible and comparable with biopsy results, making individualized treatment selection possible for NSCLC patients from whom tumor biopsies are not available.

Cystic lesions of the pancreas are being detected with increasing frequency. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is one of the most precise methods of diagnosis but still has limited accuracy. A new, through-the-needle cytologic brush system (EchoBrush; Cook Medical, Bloomington, Ind) has been approved for use during EUS evaluation of cystic pancreatic lesions. METHODS: Data from 127 EUS-FNAs of pancreatic cystic lesions were analyzed to compare the cytologic yield of EchoBrush with conventional EUS-FNA. An attending cytopathologist was present on site to assess specimen adequacy in all the cases. Diagnostic yields of both procedures, as well as related adverse events, were recorded. Statistical analysis was performed with the SPSS 15.0 version software (SPSS, Chicago, Ill). RESULTS: A total of 127 cystic lesions of the pancreas from 120 patients (42 men and 78 women, mean age of 62.17 ± 12.17 years) were included in the study. Mean size of lesions was 23.58 ± 21.69 mm. Adequacy of the samples and diagnostic yield were higher using EchoBrush. In 80 (63 %) cases, conventional EUS-FNA was performed, whereas in 47 (37%), we used EchoBrush. Diagnostic material was obtained in 85.1% (40 of 47) of cases using EchoBrush and in 66.3% (53 of 80) with conventional EUS-FNA. (P < .05). There were very few clinically relevant complications related to EUS-FNA and EUS-EchoBrush techniques. CONCLUSIONS: This study suggests that cytological specimens from pancreatic cystic lesions obtained using EchoBrush at the time of EUS are superior to conventional EUS-FNA mainly because of the higher yield of epithelial cells. Larger studies are needed to compare both methods.

Thirty consecutive surgical patients with glioblastoma, were operated upon using fluorescence induced by 5-aminolevulinic acid as guidance. The fluorescent quality of the tissue was used to take biopsies from the tumor center, from the invasive area around it and from adjacent normal-looking tissue. These samples were analyzed with HE, Ki-67 and nestin. Nestin expression in tissue surrounding glioblastoma cases was compared to tissue surrounding vascular lesions, metastasis and hippocampal sclerosis. The rate of gross total resection assessed by volumetric MRI was 83%. Using HE examination as the gold standard, fluorescence identified solid tumor with 100% positive predictive value, invasive areas with 97%, and normal tissue with 67% negative predictive value. Ki67 stained some cells in 69% of the non-fluorescent samples around the tumor. There was always strong nestin expression around the tumor but it was similar to control cases in non-glioma lesions with subacute expansion. 5-aminolevulinic acid fluorescence guidance is very reliable and can help to study the tumor-brain interface. Nestin expression is strong and constant in the tissue around the tumor, but is mostly an acute glial reaction, not specific of the neoplasm. Nestin staining is not recommended as a tumor stem cell marker.

PURPOSE: SF2/ASF is a splicing factor recently described as an oncoprotein. In the present work, we examined the role of SF2/ASF in human non-small cell lung cancer (NSCLC) and analyzed the molecular mechanisms involved in SF2/ASF-related carcinogenesis. EXPERIMENTAL DESIGN: SF2/ASF protein levels were analyzed in 81 NSCLC patients by immunohistochemistry. SF2/ASF downregulation cellular models were generated using small interfering RNAs, and the effects on proliferation and apoptosis were evaluated. Survivin and SF2/ASF expression in lung tumors was analyzed by Western blot and immunohistochemistry. Survival curves and log-rank test were used to identify the association between the expression of the proteins and time to progression. RESULTS: Overexpression of SF2/ASF was found in most human primary NSCLC tumors. In vitro downregulation of SF2/ASF induced apoptosis in NSCLC cell lines. This effect was associated with a reduction in the expression of survivin, an antiapoptotic protein widely upregulated in cancer. In fact, SF2/ASF specifically bound survivin mRNA and enhanced its translation, via a mammalian target of rapamycin complex 1 (mTORC1) pathway-dependent mechanism, through the phosphorylation and inactivation of the translational repressor 4E-BP1. Moreover, SF2/ASF promoted the stability of survivin mRNA. A strong correlation was observed between the expression of SF2/ASF and survivin in tumor biopsies from NSCLC patients, supporting the concept that survivin expression levels are controlled by SF2/ASF. Furthermore, combined expression of these proteins was associated with prognosis. CONCLUSION: This study provides novel data on the mTORC1- and survivin-dependent mechanisms of SF2/ASF-related carcinogenic