Vault RNAs: hidden gems in RNA and protein regulation.

Non-coding RNAs are important regulators of differentiation during embryogenesis as well as key players in the fine-tuning of transcription and furthermore, they control the post-transcriptional regulation of mRNAs under physiological conditions. Deregulated expression of non-coding RNAs is often identified as one major contribution in a number of pathological conditions. Non-coding RNAs are a heterogenous group of RNAs and they represent the majority of nuclear transcripts in eukaryotes. An evolutionary highly conserved sub-group of non-coding RNAs is represented by vault RNAs, named since firstly discovered as component of the largest known ribonucleoprotein complexes called "vault". Although they have been initially described 30 years ago, vault RNAs are largely unknown and their molecular role is still under investigation. In this review we will summarize the known functions of vault RNAs and their involvement in cellular mechanisms.

Wnt signalling modulates transcribed-ultraconserved regions in hepatobiliary cancers.

OBJECTIVE: Transcribed-ultraconserved regions (T-UCR) are long non-coding RNAs which are conserved across species and are involved in carcinogenesis. We studied T-UCRs downstream of the Wnt/ß-catenin pathway in liver cancer. DESIGN: Hypomorphic Apc mice (Apcfl/fl) and thiocetamide (TAA)-treated rats developed Wnt/ß-catenin dependent hepatocarcinoma (HCC) and cholangiocarcinoma (CCA), respectively. T-UCR expression was assessed by microarray, real-time PCR and in situ hybridisation. RESULTS: Overexpression of the T-UCR uc.158- could differentiate Wnt/ß-catenin dependent HCC from normal liver and from ß-catenin negative diethylnitrosamine (DEN)-induced HCC. uc.158- was overexpressed in human HepG2 versus Huh7 cells in line with activation of the Wnt pathway. In vitro modulation of ß-catenin altered uc.158- expression in human malignant hepatocytes. uc.158- expression was increased in CTNNB1-mutated human HCCs compared with non-mutated human HCCs, and in human HCC with nuclear localisation of ß-catenin. uc.158- was increased in TAA rat CCA and reduced after treatment with Wnt/ß-catenin inhibitors. uc.158- expression was negative in human normal liver and biliary epithelia, while it was increased in human CCA in two different cohorts. Locked nucleic acid-mediated inhibition of uc.158- reduced anchorage cell growth, 3D-spheroid formation and spheroid-based cell migration, and increased apoptosis in HepG2 and SW1 cells. miR-193b was predicted to have binding sites within the uc.158- sequence. Modulation of uc.158- changed miR-193b expression in human malignant hepatocytes. Co-transfection of uc.158- inhibitor and anti-miR-193b rescued the effect of uc.158- inhibition on cell viability. CONCLUSIONS: We showed that uc.158- is activated by the Wnt pathway in liver cancers and drives their growth. Thus, it may represent a promising target for the development of novel therapeutics.

Sequence variation in mature microRNA-608 and benefit from neo-adjuvant treatment in locally advanced rectal cancer patients.

Single nucleotide polymorphisms (SNPs) in microRNA genes have been associated with colorectal cancer (CRC) risk, survival and response to treatment. Conflicting results are available on the association between rs4919510, a SNP in mature miR-608 and clinical outcome in CRC. Here, we analyzed the association between rs4919510 and benefit from perioperative treatment in a randomised phase II trial of neoadjuvant Capecitabine and Oxaliplatin (CAPOX) followed by chemo-radiotherapy, surgery and adjuvant CAPOX ± Cetuximab in high-risk locally advanced rectal cancer (LARC). A total of 155/164 (94.5%) patients were assessable. 95 (61.3%) were homozygous for CC, 55 (35.5%) heterozygous (CG) and 5 (3.2%) homozygous for GG. Median follow-up was 64.9 months. In the CAPOX arm the 5-year progression-free survival (PFS) and overall survival (OS) rates were 54.6% and 60.7% for CC and 82.0% and 82.1% for CG/GG, respectively (HR PFS 0.13, 95% CI: 0.12-0.83, P = 0.02; HR OS 0.38, 95% CI: 0.14-1.01, P = 0.05). In the CAPOX-C arm PFS and OS were 73.2 and 82.2%, respectively for CC carriers and 64.6 and 73.1% for CG/GG carriers (HR PFS 1.38, 95% CI: 0.61-3.13, P = 0.44; HR OS 1.34, 95% CI: 0.52-3.48, P = 0.55). An interaction was found between study treatment and rs4919510 genotype for both PFS (P = 0.02) and OS (P = 0.07). This is the first study investigating rs4919510 in LARC. The CC genotype appeared to be associated with worse prognosis compared to the CG/GG genotype in patients treated with chemotherapy and chemo-radiotherapy alone. Addition of Cetuximab to chemotherapy and chemo-radiotherapy in CC carriers appeared to improve clinical outcome.

MicroRNA 193b-3p as a predictive biomarker of chronic kidney disease in patients undergoing radical nephrectomy for renal cell carcinoma.

BACKGROUND: A significant proportion of patients undergoing radical nephrectomy (RN) for clear-cell renal cell carcinoma (RCC) develop chronic kidney disease (CKD) within a few years following surgery. Chronic kidney disease has important health, social and economic impact and no predictive biomarkers are currently available. MicroRNAs (miRs) are small non-coding RNAs implicated in several pathological processes. METHODS: Primary objective of our study was to define miRs whose deregulation is predictive of CKD in patients treated with RN. Ribonucleic acid from formalin-fixed paraffin embedded renal parenchyma (cortex and medulla isolated separately) situated >3 cm from the matching RCC was tested for miR expression using nCounter NanoString technology in 71 consecutive patients treated with RN for RCC. Validation was performed by RT-PCR and in situ hybridisation. End point was post-RN CKD measured 12 months post-operatively. Multivariable logistic regression and decision curve analysis were used to test the statistical and clinical impact of predictors of CKD. RESULTS: The overexpression of miR-193b-3p was associated with high risk of developing CKD in patients undergoing RN for RCC and emerged as an independent predictor of CKD. The addition of miR-193b-3p to a predictive model based on clinical variables (including sex and estimated glomerular filtration rate) increased the sensitivity of the predictive model from 81 to 88%. In situ hybridisation showed that miR-193b-3p overexpression was associated with tubule-interstitial inflammation and fibrosis in patients with no clinical or biochemical evidence of pre-RN nephropathy. CONCLUSIONS: miR-193b-3p might represent a useful biomarker to tailor and implement surveillance strategies for patients at high risk of developing CKD following RN.

Emerging Therapeutic Targets and Future Directions in Advanced Gastric Cancer: A Comprehensive Review.

Metastatic gastric cancer (GC) still represents a critical clinical challenge, with limited treatment options and a poor prognosis. Most patients are diagnosed at advanced stages, limiting the chances of surgery and cure. The identification of molecular targets and the possibility of combining immune checkpoint inhibitors with chemotherapy have recently reshaped the therapeutic landscape of metastatic gastric cancer. The new classification of gastric cancer, mainly based on immunologic and molecular criteria such as programmed cell death 1 (PD-1), microsatellite instability (MSI), and human epidermal growth factor receptor 2 (HER2), has made it possible to identify and differentiate patients who may benefit from immunotherapy, targeted therapy, or chemotherapy alone. All relevant and available molecular and immunological targets in clinical practice for the systemic treatment of this disease are presented. Particular attention is given to possible future approaches, including circulating tumor DNA (ctDNA) for therapeutic monitoring, new targeting agents against molecular pathways such as fibroblast growth factor receptor (FGFR) and MET, chimeric antigen receptor (CAR)-T cells, and cancer vaccines. This review aims to provide a comprehensive understanding of current targets in advanced gastric cancer and to offer valuable insights into future directions of research and clinical practice in this challenging disease.

Targeting FGFR Pathways in Gastrointestinal Cancers: New Frontiers of Treatment.

In carcinogenesis of the gastrointestinal (GI) tract, the deregulation of fibroblast growth factor receptor (FGFR) signaling plays a critical role. The aberrant activity of this pathway is described in approximately 10% of gastric cancers and its frequency increases in intrahepatic cholangiocarcinomas (iCCAs), with an estimated frequency of 10-16%. Several selective FGFR inhibitors have been developed in the last few years with promising results. For example, targeting the FGFR pathway is now a fundamental part of clinical practice when treating iCCA and many clinical trials are ongoing to test the safety and efficacy of anti-FGFR agents in gastric, colon and pancreatic cancer, with variable results. However, the response rates of anti-FGFR drugs are modest and resistances emerge rapidly, limiting their efficacy and causing disease progression. In this review, we aim to explore the landscape of anti-FGFR inhibitors in relation to GI cancer, with particular focus on selective FGFR inhibitors and drug combinations that may lead to overcoming resistance mechanisms and drug-induced toxicities.

Anti-Claudin Treatments in Gastroesophageal Adenocarcinoma: Mainstream and Upcoming Strategies.

Claudins (CLDNs) are a multigene family of proteins and the principal components of tight junctions (TJs), which normally mediate cell-cell adhesion and selectively allow the paracellular flux of ions and small molecules between cells. Downregulation of claudin proteins increases the paracellular permeability of nutrients and growth stimuli to malignant cells, which aids the epithelial transition. Claudin 18.2 (CLDN18.2) was identified as a promising target for the treatment of advanced gastroesophageal adenocarcinoma (GEAC), with high levels found in almost 30% of metastatic cases. CLDN18.2 aberrations, enriched in the genomically stable subgroup of GEAC and the diffuse histological subtype, are ideal candidates for monoclonal antibodies and CAR-T cells. Zolbetuximab, a highly specific anti-CLDN18.2 monoclonal antibody, demonstrated efficacy in phase II studies and, more recently, in the phase III SPOTLIGHT trial, with improvements in both PFS and OS with respect to standard chemotherapy. Anti-CLDN18.2 chimeric antigen receptor (CAR)-T cells showed a safety profile with a prevalence of hematologic toxicity in early phase clinical trials. The aim of this review is to present new findings in the treatment of CLDN18.2-positive GEAC, with a particular focus on the monoclonal antibody zolbetuximab and on the use of engineered anti-CLDN18.2 CAR-T cells.

Thrombotic Events during Lenvatinib Treatment: A Single Institution Experience.

Lenvatinib is the standard treatment for radioiodine-refractory differentiated thyroid cancer (RR-DTC). Thromboembolic (TE) side effects are quite rare (1-3% of treated patients) in clinical trials. Nevertheless, patients with predisposing factors are at a higher risk of developing cardiovascular adverse events. Reduction of lenvatinib starting dose and cardiologic counselling to provide appropriate supportive therapies are usually recommended for high-risk patients. From 2016 to 2022, we analyzed a series of 16 patients who were consecutively treated at our institution. All except one patient received a reduction in their dosage after two cycles of therapy because of toxicities, and four patients (25%) suffered from TE. The observed incidence in our patient sample seemed to be higher than expected. We hypothesized that our patient sample might be at higher risk probably because of the heavy prior loco-regional treatments performed.

Papillary Thyroid Carcinoma: Molecular Distinction by MicroRNA Profiling.

Papillary thyroid carcinoma (PTC) is a miscellaneous disease with a variety of histological variants, each with its own mutational profile, and clinical and prognostic characteristics. Identification of microRNA (miRNA) expression profiles represents an important benchmark for understanding the molecular mechanisms underlying the biological behavior of these unique PTC subtypes in order that they be better characterized. We considered a series of 35 PTC samples with a histological diagnosis of either hobnail (17 cases) or classical variant (nine cases) and with a specific BRAF p.K601E mutation (nine cases). We determined the overall miRNA expression profile with NanoString technology, and both quantitative reverse transcription-PCR and in situ hybridization were used to confirm selected miRNAs. The miRNA signature was found to consistently differentiate specific histotypes and mutational profiles. In contrast to the BRAF p.K601E mutation and classic PTCs, three miRNAs (miR-21-5p, miR-146b-5p, and miR-205-5p) were substantially overexpressed in the hobnail variant. The current study found that different miRNA signature profiles were linked to unique histological variants and BRAF mutations in PTC. Further studies focusing on the downstream pathogenetic functions of mRNAs in thyroid neoplasms are warranted.

NTRK fusions in colorectal cancer: clinical meaning and future perspective.

INTRODUCTION: Despite the efforts of the scientific community, the prognosis of metastatic colorectal cancer (mCRC) remains poor. Actionable gene fusions such as Neurotrophic Tropomyosin Receptor Kinases (NTRK) rearrangements are rare but might represent a new target to improve outcomes in this setting. The first-generation TRK inhibitors, larotrectinib and entrectinib, have demonstrated efficacy and safety in mCRC cancer patients exhibiting NTRK pathogenic fusions. Moreover, second-generation molecules are emerging, able to overcome the acquired resistance to NTRK blocking. AREAS COVERED: This review aims to report the current knowledge and the available evidence on NTRK fusion in mCRC, with a focus on molecular bases, clinical characteristics, prognostic meaning, and new therapeutic approaches, from the perspective of the clinical oncologist. EXPERT OPINION: Considering the limited options associated with the treatment of mCRC patients, the possibility of identifying new molecular biomarkers is an urgent clinical need. The availability of new molecular targets and the combinations of different agents might represent the true breakthrough point, allowing for change in the clinical course of colorectal cancer patients.

Challenges and perspectives for immunotherapy in oesophageal cancer: A look to the future (Review).

Oesophageal cancer is one of the most aggressive malignancies with limited treatment options, thus resulting in a high morbidity and mortality. With 5­year survival rates of only 5­10%, oesophageal cancer holds a dismal prognosis for patients. In order to improve overall survival, the early diagnosis and tools for patient stratification for personalized treatment are urgent needs. A minority of oesophageal cancers belong to the spectrum of Lynch syndrome­associated cancers and are characterized by microsatellite instability (MSI). Microsatellite instability is a consequence of defective mismatch repair protein functions and it has been well characterized in other gastrointestinal tumours, such as colorectal and gastric cancer. In the latter, high levels of MSI are associated with a better prognosis and with an increased benefit to immune­based therapies. Therefore, similar therapeutic approaches could offer an opportunity of treatment for oesophageal cancer patients with MSI. Apart from immune checkpoint inhibitors, other immunotherapies such as adoptive T­cell transfer, peptide vaccine and oncolytic viruses are under investigation in oesophageal cancer patients. In the present review, the rationale and current knowledge about immunotherapies in oesophageal cancer are summarised.

Acute pancreatitis after the removal of a hyperplastic duodenal polyp: a case report.

A 59-year-old patient underwent the duodenal endoscopic mucosal resection of a hyperplastic polyp. Four hours after the procedure she developed severe epigastric pain. Laboratory and imaging results were consistent with mild acute edematous pancreatitis. After several days of dietary therapy and intravenous crystalloid fluids the patient recovered, and 1 month later was asymptomatic and had no signs of pancreatic inflammation. This case illustrates a rare but clinically important complication of therapeutic upper endoscopy, which may be attributable to thermal injury of the duodenal wall and the adjacent pancreas. It also underscores the importance of the close follow up of patients who undergo invasive endoscopic procedures and the need for additional preventive measures to be taken when resecting duodenal lesions.

Dominant-negative inhibition of Ets 1 suppresses tumor growth, invasion and migration in rat C6 glioma cells and reveals differentially expressed Ets 1 target genes.

We previously reported that the inactivation of the Ets 1 transcription factor by a specific decoy strategy reduces rat C6 glioma cell proliferation and mmp-9 expression. In the present study, we analysed the effects of the dominant-negative form of Ets 1 (Ets-DB) on rat C6 glioma cell proliferation, migration, invasion, in vivo tumor growth on the chicken chorioallantoic membrane (CAM) and mmp-9 expression. In addition, we examined differences in gene expression between Ets-DB expressing and control cells using suppression subtractive hybridization (SSH). We found that retrovirus mediated expression of Ets-DB inhibited cellular proliferation, migration, invasion, mmp-9 expression, cellular growth in soft agar, and in vivo growth in the chicken chorioallantoic membrane assay. SSH analysis revealed expression of different genes in Ets-DB expressing cells involved in basic cellular processes. Each of these genes contained binding sites for different Ets-factors within their promoters. Finally, we found that, in addition to Ets 1, Elk-1, Elf-1, Fli-1 and Etv-1 are further Ets family members expressed in rat C6 glioma cells. Our results indicate that Ets transcription factors play important roles for basic properties of rat C6 glioma cells. Targeting of these factors might therefore become a useful experimental tool for therapeutic strategies against malignant gliomas.

Biliary tract cancer: current challenges and future prospects.

PURPOSE: Incidence and mortality of biliary tract carcinoma (BTC) are increasing, especially in South America and Asia. Such a disease often bears a dismal prognosis because of diagnosis occurring at late stages and for the frequent relapses after surgery. The aims of this review were to summarize the state of the art of the treatment of BTC and give a view at possible future prospects linked with molecular profiling, immunotherapy, and targeted therapies. DESIGN: We conducted a systematic literature search using MEDLINE and the 2018 ASCO Meeting abstract databases to identify published clinical trials, translational series, and meeting abstracts. All significant papers and abstracts available to date were included. RESULTS: For resected BTC, thanks to the BILCAP study, adjuvant chemotherapy (CT) with capecitabine should be regarded as the new standard of care. For locally advanced inoperable and metastatic diseases, the use of chemoradiotherapy and radioembolization has not been supported by any randomized Phase III study. The standard of care remains the combination of CT with gemcitabine and cisplatin, as reported by the ABC-02 trial. All targeted therapies have failed to improve the survival outcomes, either in combination with CT or as single agents and are not recommended in the treatment of BTC. Whole-exome sequencing and molecular profiling have helped in identifying genetic signatures typical of different BTC subtypes. With this support, new trials with targeted agents and immunotherapy have been designed, and results are awaited. CONCLUSION: BTC still remains a disease with very few treatment options. Different BTC subtypes own peculiar gene mutations and pathways alterations. Therefore, molecular profiling may be the only key to enable new tailored strategies with targeted agents and immunotherapy.

Major innovations and clinical applications of disodium-levofolinate: a review of available preclinical and clinical data.

The association of folinate salts with 5-fluorouracil (5-FU) represents a gold standard in the treatment of many cancers. In several clinical trials, the simultaneous administration of calcium-folinic acid (Ca-FA) and the prolonged infusion of 5-FU resulted in a better clinical response compared with fluoropyrimidine alone and 5-FU bolus. However, the simultaneous infusion of 5-FU and Ca-FA mixed in the same infusion pump is hindered by the crystallization of calcium salts, which eventually leads to catheter obstruction and damage. The sodium salt of leucovorin-disodium levofolinate (Na-Lv) is a novel molecule with a pharmacological profile similar to Ca-FA. Owing to its higher solubility, it can be safely mixed with 5-FU in a single pump without the risk of precipitation and catheter occlusion. The efficacy and safety of Na-Lv have been widely examined in preclinical and clinical phase II studies in combination with various schedules of 5-FU and in several cancer types. PubMed, EMBASE, SCOPUS and Web of Science databases were searched from inception to November 2018 to retrieve available published phase I and II series, including Western patients. Compared with Ca-FA, Na-Lv shows a more favourable efficacy and toxicity profile in terms of overall response rate, progression-free survival, time to progression and occurrence of severe adverse events. Moreover, it allows treatment time to be shortened, decreasing the number of required human resources for drug administration and limiting the occurrence of catheter damage.

Use of Antibiotics and Risk of Cancer: A Systematic Review and Meta-Analysis of Observational Studies.

The association between antibiotic use and risk of cancer development is unclear, and clinical trials are lacking. We performed a systematic review and meta-analysis of observational studies to assess the association between antibiotic use and risk of cancer. PubMed, the Cochrane Library and EMBASE were searched from inception to 24 February 2019 for studies reporting antibiotic use and subsequent risk of cancer. We included observational studies of adult subjects with previous exposure to antibiotics and available information on incident cancer diagnoses. For each of the eligible studies, data were collected by three reviewers. Risk of cancer was pooled to provide an adjusted odds ratio (OR) with a 95% confidence interval (CI). The primary outcome was the risk of developing cancer in ever versus non-antibiotic users. Cancer risk's association with antibiotic intake was evaluated among 7,947,270 participants (n = 25 studies). Overall, antibiotic use was an independent risk factor for cancer occurrence (OR 1.18, 95%CI 1.12-1.24, p < 0.001). The risk was especially increased for lung cancer (OR 1.29, 95%CI 1.03-1.61, p = 0.02), lymphomas (OR 1.31, 95%CI 1.13-1.51, p < 0.001), pancreatic cancer (OR 1.28, 95%CI 1.04-1.57, p = 0.019), renal cell carcinoma (OR 1.28, 95%CI 1.1-1.5, p = 0.001), and multiple myeloma (OR 1.36, 95%CI 1.18-1.56, p < 0.001). There is moderate evidence that excessive or prolonged use of antibiotics during a person's life is associated with slight increased risk of various cancers. The message is potentially important for public health policies because minimizing improper antibiotic use within a program of antibiotic stewardship could also reduce cancer incidence.

Influence of preoperative core biopsies on uPA/PAI-1 expression in breast cancer tissue.

The urokinase-type plasminogen activator (uPA) and the plasminogen activator inhibitor-1 (PAI-1) are involved in tumor invasion and metastasis as well as wound healing and inflammation. We investigated the impact of tissue injury by preoperative sampling on the level of uPA/PAI-1 in paraffin tissue of 55 breast cancer cases by immunohistochemistry. The tumor area surrounding the biopsy channel was compared with distant intact tumor tissue. uPA and PAI-1 were constantly expressed by the tumor cells. Fibroblastic expression was higher in the tumor area surrounding the biopsy channel than in intact tissue with 47 vs 29 positive cases for uPA (p<0.001) and 35 vs 25 positive cases for PAI-1 (p=0.055). A decrease in fibroblastic enzyme expression from the biopsy area to the intact tumor tissue was seen in 21 cases for uPA and 16 cases for PAI-1. This difference was most evident in cases with an interval of 6 days and longer between biopsy and surgery. In conclusion, fibroblastic inflammatory reaction around the biopsy channel affects stromal uPA and PAI-1 expression, which possibly leads to falsely increased enzyme levels in ELISA. Tissue specimen for ELISA analysis should not be taken from the tumor area around the biopsy channel in the resection specimen.

The transcription factor ETS-1: its role in tumour development and strategies for its inhibition.

Transcription factors are an important group of proteins. Changes in expression or activity of transcription factors result in diverse and manifold effects on the whole transcriptome of the cell. Therefore transcription factors are of special interest in physiological as well as pathological processes particularly tumour development and progression. In this review we focus on Ets-1, the prototype of the ETS family of transcription factors. ETS family members play important roles in development, differentiation and proliferation of cells in general and they are involved in apoptosis and tissue remodelling as well. Most of them are downstream nuclear targets of Ras-MAP kinase signalling and the deregulation of ets genes results in malignant transformation of different cells. Several ets genes are rearranged in human leukaemia, Ewing tumours and prostate cancer to produce chimeric oncoproteins. Furthermore, an aberrant expression of several ets genes is often observed in various types of human malignant tumours. With regard to the involvement of some ETS transcription factors, especially Ets-1, in malignant transformation and tumour progression (including invasion, metastasis and neoangiogenesis) through transactivation of cancer related genes, they are potential molecular targets for selective cancer therapy. In this review we focus on the roles of Ets-1 for tumour development and progression with special emphasis on tumour vascularization and invasion. We then discuss specific strategies for Ets-1 inhibition as a potential tool for cancer treatment.

Tumor-stroma interactions of metastatic prostate cancer cell lines: analyses using microarrays.

Tumor-stroma interactions are of great importance not only for the development and progression of primary prostate carcinoma but probably also for the establishment of metastasis. Fibroblasts are an important stromal cell type encountered by metastatic tumor cells at different sites. In previous investigations, we had found that media conditioned by three metastatic prostate cancer cell lines (LNCaP, PC-3, and DU-145) induced cultured nonprostatic fibroblasts to proliferate or to express matrix-metalloproteinase-1 considered important for tumor invasion. Fibroblast-conditioned media in turn stimulate proliferation of DU-145 cells and migration of PC-3 cells. Both tumor cells and fibroblasts secrete VEGF suggesting that not only metastatic but also stromal cells at metastatic sites contribute to the vascularization of metastasis necessary for continuous growth. In order to better understand the reciprocal tumor-stroma cross-talk in molecular terms we used the mRNA extracted from stimulated and unstimulated neoplastic and fibroblastic stromal cells for cDNA array hybridization using Affymetrix chips. The three prostate cell lines influenced the fibroblasts nearly in the same manner. In particular proteins involved in cell adhesion, cell-cell contact, and cell cycle regulation were downregulated in stimulated fibroblasts. In contrast, fibroblasts affected every prostate cancer cell line in different ways, which may be because of the different origin of the metastatic prostate cancer cell lines.

Clinical development of mTor inhibitors for renal cancer.

INTRODUCTION: Renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and 90-95% of neoplasms arising from the kidney. In the last 10 years, clinical trials have established multitargeted tyrosine kinase inhibitors (TKIs) as the standard first-line treatment in patients with metastatic disease. Multiple agents are now available for treatment in subsequent lines.The mammalian target of rapamycin (mTOR) inhibitors (e.g., everolimus alone or with lenvatinib) are among the most effective options. Areas covered: This paper provides a complete and updated overview on mTOR inhibitors for the treatment of advanced RCC. The authors revised the results of the most recent completed clinical trials and provided information about ongoing trials. Expert opinion: mTOR pathway still represents an important driver for RCC management. Combination of everolimus and lenvatinib is considered a category 1 choice with cabozantinib and nivolumab for subsequent therapy in metastatic RCC according to NCCN guidelines v2.2017. These three treatments (levantinib/everolimus, cabozantinib, and nivolumab) all resulted in a superior efficacy compared to everolimus alone. Moreover, mTOR inhibitors, and in particular temsirolimus for poor risk patients, are available choices for treatment in non-clear cell carcinomas together with TKIs.