Pathological complete response achieved with FLOT chemotherapy in two patients with MSI-H esophagogastric junction and gastric adenocarcinoma.

Globally, more than 1 million new cases of gastric cancer were estimated in 2020, ranking fourth in cancer mortality. Currently although in resectable gastric cancer and esophagogastric junction (EGJ) adenocarcinoma a perioperative triplet chemotherapy regimen including a fluoropyrimidine, a platinum compound and docetaxel (FLOT) demonstrated a better overall survival, the survival rate is still very low, and a massive effort is still required to improve clinical prognosis. High microsatellite instability (MSI-H) status in gastric cancer is a favorable prognostic factor but poor data are available on its predictive role for perioperative FLOT chemotherapy in resectable gastric cancer. Here, we presented the case of two patients with advanced MSI-H gastric cancer/EGJ adenocarcinoma who had no residual tumor following neoadjuvant FLOT chemotherapy maintaining a complete response for more than 30 months, suggesting MSI-H status to be a positive prognostic marker also in patients treated with a taxane-containing triplet in this setting. We also discuss the future perspectives including the opportunity to achieve excellent clinical outcomes with immune checkpoint inhibitor (ICI)-based regimens.

Long-term response of more than 9 years to regorafenib in a heavily pretreated patient with metastatic colorectal cancer.

Colorectal cancer (CRC) is the third most common cancer worldwide, with approximately 1.9 million new diagnoses and 935 000 deaths annually. Overall, there is accumulating evidence that receiving all available treatments leads to a survival advantage and, although tailored treatments might be appropriate for selected patients, the one-size-fits-all approach is still widely used in chemo-refractory patients. Currently, different antiangiogenics and multitarget agents are indicated in treatment of metastatic CRC (mCRC) whereas the identification of useful predictive factors for the treatment response is lacking. Analysis of potential predictive biomarkers of efficacy of regorafenib is still ongoing but may prove to be difficult because of its nonspecific activity across a wide range of angiogenic, oncogenic, stromal, and intracellular signaling kinases. We present a case of a 57-year-old Caucasian woman diagnosed with recurrence after curative surgery for rectal adenocarcinoma stage III (ypT3N2). Despite undergoing multiple lines of standard chemotherapy, disease control could not be maintained. Consequently, regorafenib, a multikinase inhibitor with antiangiogenic proprieties, was started as a late-line treatment and a dose reduction strategy allowed a long-term response of more than 9 years with good tolerability.

Practical tips and new trends in electrochemical biosensing of cancer-related extracellular vesicles.

To tackle cancer and provide prompt diagnoses and prognoses, the constantly evolving biosensing field is continuously on the lookout for novel markers that can be non-invasively analysed. Extracellular vesicles (EVs) may represent a promising biomarker that also works as a source of biomarkers. The augmented cellular activity of cancerous cells leads to the production of higher numbers of EVs, which can give direct information on the disease due to the presence of general and cancer-specific surface-tethered molecules. Moreover, the intravesicular space is enriched with other molecules that can considerably help in the early detection of neoplasia. Even though EV-targeted research has indubitably received broad attention lately, there still is a wide lack of practical and effective quantitative procedures due to difficulties in pre-analytical and analytical phases. This review aims at providing an exhaustive outline of the recent progress in EV detection using electrochemical and photoelectrochemical biosensors, with a focus on handling approaches and trends in the selection of bioreceptors and molecular targets related to EVs that might guide researchers that are approaching such an unstandardised field.

Prognostic role of sodium levels in colorectal cancer patients receiving aflibercept plus FOLFIRI.

Aim: To investigate the impact of natremia in metastatic colorectal cancer (mCRC) patients treated with aflibercept plus folinic acid, 5-fluorouracil, oxaliplatin and irinotecan (FOLFIRI). Patients & methods: A total of 84 mCRC patients receiving aflibercept plus FOLFIRI as second-line treatment were enrolled and divided into two groups based on their median sodium value. Progression-free survival and overall survival were analyzed. Results: Patients with sodium levels ≥140 mEq/l had significantly longer median progression-free survival (4.1 vs 2 months; p < 0.01) and median overall survival (12 vs 7.3 months; p < 0.01) compared with those with lower levels. Conclusion: This study suggests that higher pretreatment serum sodium levels are associated with improved outcomes in mCRC patients receiving aflibercept and FOLFIRI, potentially serving as a prognostic marker to aid treatment management.

What is this article about? Colorectal cancer (CRC) is a common and deadly disease. Despite advances in treatment options, the prognosis remains poor for patients who progress beyond the first-line therapy. Antiangiogenic therapy, which targets blood vessel growth in tumors, has become an important treatment approach for metastatic CRC (mCRC). Aflibercept is a drug used in combination with chemotherapy to treat mCRC patients who have progressed after initial treatment. However, there is limited knowledge about factors that can predict the effectiveness of this treatment. This study aimed to investigate the relationship between sodium levels and treatment outcomes in 84 mCRC patients receiving aflibercept and chemotherapy as second-line therapy. What were the results? The results showed that patients with baseline sodium levels of ≥140 mEq/l had significantly longer progression-free survival and overall survival compared with patients with lower sodium levels. This finding suggests that baseline serum sodium levels could serve as a prognostic factor for survival outcomes in mCRC patients treated with aflibercept and chemotherapy. Other factors associated with better survival outcomes included longer survival without disease progression after first-line chemotherapy, receiving maintenance treatment with aflibercept and completing more treatment cycles. What do the results of the study mean? This study highlights the potential significance of serum sodium levels as a predictor of treatment effectiveness in mCRC patients. Further research is needed to confirm these findings and better understand the underlying mechanisms. Evaluating serum sodium levels could be a useful tool in predicting outcomes and improving treatment strategies for mCRC patients.

Evaluation of Fruquintinib in the Continuum of Care of Patients with Colorectal Cancer.

The management of patients with metastatic colorectal cancer (mCRC) has the continuum of care as the treatment paradigm. To date, trifluridine/tipiracil, a biochemically modulated fluoropyrimidine, and regorafenib, a multi-kinase inhibitor, remain the main options for the majority of patients who progressed to standard doublet- or triplet-based chemotherapies, although a tailored approach could be indicated in certain circumstances. Being highly selective for vascular endothelial growth factor receptor (VEGFR)-1, -2 and -3, fruquintinib demonstrated a strong anti-tumor activity in preclinical models and received approval from China's National Medical Products Administration (NMPA) in 2018 for the treatment of patients with chemo-refractory mCRC. The approval was based on the results of the phase III FRESCO trial. Then, in order to overcome geographic differences in clinical practice, the FRESCO-2 trial was conducted in the US, Europe, Japan, and Australia. In a heavily pretreated patient population, the study met its primary endpoint, demonstrating an advantage of fruquintinib over a placebo in overall survival (OS). Here, we review the clinical development of fruquintinib and its perspectives in gastrointestinal cancers. Then, we discuss the introduction of fruquintinib in the continuum of care of CRC paying special attention to unmet needs, including the identification of cross-resistant and potentially susceptible populations, evaluation of radiological response, and identification of novel biomarkers of clinical benefit.

Perioperative Tailored Treatments for Gastric Cancer: Times Are Changing.

Resectable gastric or gastroesophageal (G/GEJ) cancer is a heterogeneous disease with no defined molecularly based treatment strategy. Unfortunately, nearly half of patients experience disease recurrence despite standard treatments (neoadjuvant and/or adjuvant chemotherapy/chemoradiotherapy and surgery). In this review, we summarize the evidence of potential tailored approaches in perioperative treatment of G/GEJ cancer, with a special focus on patients with human epidermal growth factor receptor-2(HER2)-positive and microsatellite instability-high (MSI-H) tumors. In patients with resectable MSI-H G/GEJ adenocarcinoma, the ongoing INFINITY trial introduces the concept of non-operative management for patients with complete clinical-pathological-molecular response, and this could be a novel and potential practice changing strategy. Other pathways involving vascular endothelial growth factor receptor (VEGFR), fibroblast growth factor receptor (FGFR), claudin18 isoform 2 (CLDN18.2), and DNA damage repair proteins are also described, with limited evidence until now. Although tailored therapy appears to be a promising strategy for resectable G/GEJ cancer, there are several methodological issues to address: inadequate sample size for pivotal trials, underestimation of subgroup effects, and choice of primary endpoint (tumor-centered vs. patient-centered endpoints). A better optimization of G/GEJ cancer treatment allows maximizing patient outcomes. In the perioperative phase, although caution is mandatory, times are changing and tailored strategies could introduce new treatment concepts. Overall, MSI-H G/GEJ cancer patients possess the characteristics to be the subgroup that could receive the most benefit from a tailored approach.

An improved NMR approach for metabolomics of intact serum samples.

NMR metabolomics has inherent capabilities for studying biofluids, such as reproducibility, minimal sample preparation, non-destructiveness, and molecular structure elucidation; however, reliable quantitation of metabolites is still a challenge because of the complex matrix of the samples. The serum is one of the most common samples in clinical studies but possibly the most difficult for NMR analysis because of the high content of proteins, which hampers the detection and quantification of metabolites. Different processes for protein removal, such as ultrafiltration and precipitation, have been proposed, but require sample manipulation, increase time and cost, and possibly lead to loss of information in the metabolic profile. Alternative methods that rely on filtering protein signals by NMR pulse sequencing are commonly used, but standardisation of acquisition parameters and spectra calibration is far from being reached. The present technical note is a critical assessment of the sparsely suggested calibrants, pulse sequences and acquisition parameters toward an optimised combination of the three for accurate and reproducible quantification of metabolites in intact serum.

Growth arrest-specific 5 lncRNA as a valuable biomarker of chemoresistance in osteosarcoma.

Osteosarcoma is the most common primary malignant bone tumour in children and teenagers, and it is characterised by drug resistance and high metastatic potential. Increasing studies have highlighted the critical roles of long noncoding RNAs (lncRNAs) as oncogenes or tumour suppressors as well as new biomarkers and therapeutic targets in osteosarcoma. The growth arrest-specific 5 (GAS5) lncRNA can function as a tumour suppressor in several cancers. The present study aimed to validate GAS5 and other chemoresistance-associated lncRNAs as biomarkers in a cohort of primary osteosarcoma samples, to obtain predictive information on resistance or sensitivity to treatment. The GAS5 and a panel of lncRNAs related to chemoresistance [SNGH1, FOXD2-AS1, deleted in lymphocytic leukemia (DLEU2) and LINC00963] were evaluated in a cohort of osteosarcoma patients enrolled at the Careggi University Hospital. Total RNA was extracted from formalin-fixed paraffin-embedded (FFPE) tissue sections and the expression levels of the lncRNAs were quantified by qPCR. A bioinformatic analysis on deposited RNA-seq data was performed to validate the qPCR results. Clustering analysis shows that GAS5 could be linked to the expression of isoforms 02 and 04 of the lncRNA DLEU2, whereas the DLEU2 isoform 08 is linked to the lncRNA LINC00963. We found that GAS5 is significantly increased in patients with a good prognosis and is expressed differently between chemosensitive and chemoresistant osteosarcoma patients. However, the results obtained are not concordant with the in-silico analysis performed on the TARGET osteosarcoma dataset. In the future, we would enlarge the case series, including different disease settings.

Alteration of the Nucleotide Excision Repair (NER) Pathway in Soft Tissue Sarcoma.

Clinical responses to anticancer therapies in advanced soft tissue sarcoma (STS) are unluckily restricted to a small subgroup of patients. Much of the inter-individual variability in treatment efficacy is as result of polymorphisms in genes encoding proteins involved in drug pharmacokinetics and pharmacodynamics. The nucleotide excision repair (NER) system is the main defense mechanism for repairing DNA damage caused by carcinogens and chemotherapy drugs. Single nucleotide polymorphisms (SNPs) of NER pathway key genes, altering mRNA expression or protein activity, can be significantly associated with response to chemotherapy, toxicities, tumor relapse or risk of developing cancer. In the present study, in a cohort of STS patients, we performed DNA extraction and genotyping by SNP assay, RNA extraction and quantitative real-time reverse transcription PCR (qPCR), a molecular dynamics simulation in order to characterize the NER pathway in STS. We observed a severe deregulation of the NER pathway and we describe for the first time the effect of SNP rs1047768 in the ERCC5 structure, suggesting a role in modulating single-stranded DNA (ssDNA) binding. Our results evidenced, for the first time, the correlation between a specific genotype profile of ERCC genes and proficiency of the NER pathway in STS.

Circulating tumour cells and cell-free DNA as a prognostic factor in metastatic colorectal cancer: the OMITERC prospective study.

BACKGROUND: Within the OMITERC prospective study (OMIcs application from solid to liquid biopsy for a personalised ThERapy of Cancer), we explored the prognostic role of liquid biopsy encompassing cell-free DNA (cfDNA) and circulating tumour cells (CTCs) in KRAS mutated metastatic colorectal cancer (mCRC). METHODS: We defined a workflow including pre-analytical and analytical procedures collecting blood before therapy and every 3 months until disease progression (PD). CTCs were counted by CellSearch® and isolated by DEPArray™. NGS sequencing of CTCs and cfDNA was performed using a panel of cancer/CRC related genes respectively. RESULTS: KRAS mutational status was mostly concordant between tumour tissues and liquid biopsy. The percentage of cfDNA samples with mutations in CRC driver genes was in line with literature. In longitudinal monitoring circulating biomarkers anticipated or overlapped conventional diagnostic tools in predicting PD. The presence of CTCs at baseline was confirmed a negative prognostic marker. CONCLUSIONS: Cell-free DNA and CTCs are readily available candidates for clinical application in mCRC. While CTCs demonstrated a prognostic significance at baseline, cfDNA was confirmed an easily accessible material for monitoring the mutational status of the tumour over time. Moreover, in the longitudinal study, the two markers emerged as complementary in assessing disease progression.

Results of the observational prospective RealFLOT study.

BACKGROUND: Perioperative FLOT (5-fluorouracil, oxaliplatin and docetaxel) has recently become the gold standard treatment for fit patients with operable gastric (GC) or gastroesophageal (GEJ) adenocarcinoma, getting a 5-year overall survival (OS) of 45%, over 23% with surgery alone. METHODS: RealFLOT is an Italian, multicentric, observational trial, collecting data from patients with resectable GC or GEJ adenocarcinoma treated with perioperative FLOT. Aim of the study was to describe feasibility and safety of FLOT, pathological complete response rate (pCR), surgical outcomes and overall response rate (ORR) in an unselected real-world population. Additional analyses evaluated the correlation between pCR and survival and the prognostic role of microsatellite instability (MSI) status. RESULTS: Of 206 patients enrolled that received perioperative FLOT at 15 Italian centers, 124 (60.2%) received at least 4 full-dose cycles, 190 (92.2%) underwent surgery, and 142 (68.9%) started the postoperative phase. Among patients who started the postoperative phase, 105 (51.0%) received FLOT, while 37 (18%) received de-intensified regimens, depending on clinical condition or previous toxicities. pCR was achieved in 7.3% of cases. Safety profile was consistent with literature. Neutropenia was the most common G 3-4 adverse event (AE): 19.9% in the preoperative phase and 16.9% in the postoperative phase. No toxic death was observed and 30-day postoperative mortality rate was 1.0%. ORR was 45.6% and disease control rate (DCR) was 94.2%. Disease-free survival (DFS) and OS were significantly longer in case of pCR (p = 0.009 and p = 0.023, respectively). A trend towards better DFS was observed among MSI-H patients. CONCLUSIONS: These real-world data confirm the feasibility of FLOT in an unselected population, representative of the clinical practice. pCR rate was lower than expected, nevertheless we confirm pCR as a predictive parameter of survival. In addition, MSI-H status seems to be a positive prognostic marker also in patients treated with taxane-containing triplets.

Anticancer effects against colorectal cancer models of chloro(triethylphosphine)gold(I) encapsulated in PLGA-PEG nanoparticles.

Chloro(triethylphosphine)gold(I), (Et3PAuCl hereafter), is an Auranofin (AF)-related compound showing very similar biological and pharmacological properties. Like AF, Et3PAuCl exhibits potent antiproliferative properties in vitro toward a variety of cancer cell lines and is a promising anticancer drug candidate. We wondered whether Et3PAuCl encapsulation might lead to an improved pharmacological profile also considering the likely reduction of unwanted side-reactions that are responsible for adverse effects and for drug inactivation. Et3PAuCl was encapsulated in biocompatible PLGA-PEG nanoparticles (NPs) and the new formulation evaluated in colorectal HCT-116 cancer cells in comparison to the free gold complex. Notably, encapsulated Et3PAuCl (nano-Et3PAuCl hereafter) mostly retains the cellular properties of the free gold complex and elicits even greater cytotoxic effects in colorectal cancer (CRC) cells, mediated by apoptosis and autophagy. Moreover, a remarkable inhibition of two crucial signaling pathways, i.e. ERK and AKT, by nano-Et3PAuCl, was clearly documented. The implications of these findings are discussed.

Association of Systemic Steroid Treatment and Outcome in Patients Treated with Immune Checkpoint Inhibitors: A Real-World Analysis.

BACKGROUND: Immune-related adverse events (irAEs) are inflammatory side effects, which can occur during immune-checkpoint(s) inhibitors (ICIs) therapy. Steroids are the first-line agents to manage irAEs because of their immunosuppressive properties. However, it is still debated whether or when steroids can be administered without abrogating the therapeutic efforts of immunotherapy. METHODS: We retrospectively evaluated 146 patients with metastatic non-small cell lung cancer (NSCLC), melanoma and renal cell carcinoma (RCC) treated with ICIs. We assessed the progression-free survival (PFS) of patients treated with steroids due to an irAE compared to a no-steroid group. RESULTS: The early treatment with steroid (within the first 30 days from the beginning of immunotherapy) was not related to a shorter PFS (p = 0.077). Interestingly, patients who were treated with steroids after 30 days from the start of immunotherapy had significantly longer PFS (p = 0.017). In a multivariate analysis, treatment with steroids after 30 days was an independent prognostic factor for PFS (HR: 0.59 [95% CI 0.36-0.97], p = 0.037). CONCLUSIONS: This retrospective study points out that early systemic steroids administration to manage irAEs might not have a detrimental effect on patient clinical outcome in NSCLC, melanoma and RCC patients.

Somatostatin analogs in pregnant patients with neuroendocrine tumor.

Somatostatine analogs (SSAs) are currently indicated in the treatment of acromegaly and neuroendocrine tumors (NETs). Actually, pregnancy in patients with acromegaly and NETs does not represent an exceptional event because reproductive behavior has changed in the last decades and patients with NETs show more frequently long-term survival. The safety profile of SSAs during pregnancy is still controversial. Concerning acromegaly, based on case reports and series, SSAs administration during pregnancy seems to be relatively well tolerated. Concerning patients with NETs, up to date only one patient with NET receiving SSA during pregnancy has been reported in literature. We report two cases of gastroenteropancreatic-NET patients receiving SSA lanreotide for the entire course of their pregnancy, with favorable outcomes for both mothers and babies. Our experience supports the possibility to continue safely SSA lanreotide during pregnancy in patients with NET.

Mutational profile in circulating tumor DNA in a patient affected by low-risk endometrial cancer: predictable tool of relapse?

Endometrial cancer is the commonest gynecological cancer, the majority is endometrioid type, diagnosed at an early stage with 69-88% 5-year survival. Low-grade endometrial cancers have low recurrence rates and often do not receive adjuvant therapy; however, a subset of these patients will have poor outcomes and would benefit from adjuvant treatment has been challenging. We evaluate the circulating cell-free DNA (ccfDNA) in a patient with low-risk endometrial cancer in order to identify the presence of molecular markers associated with risk of recurrence. The evaluation of mutation profile was performed by next-generation sequencing (NGS) in primary tumor formalin-fixed paraffin-embedded (FFPE) tissue and in circulating tumor DNA (ctDNA). We identified a specific mutational profile in ctDNA, different from primary tumor tissue suggesting that the clone involved in the relapse may be different in comparison to the most represented in the primary tumor. These findings open new prospective and new wonderings. The molecular characterization of tissue may be useful for setting new target personalized therapy even in the treatment of endometrial cancer, moreover, endometrial cancer at low risk should be not underestimated for the incidence of relapse, and for this evaluation the molecular characterization may be useful. Moreover, these results suggest that the single analysis of primary tumors may be not sufficient for setting a specific personalized therapy targeted to avoid the relapse but may be necessary to join the molecular characterization of liquid biopsy to primary tissue.

Detection of PIK3CA E545A mutation in circulating tumor DNA of a patient affected by uterine carcinosarcoma.

Uterine carcinosarcomas are biphasic neoplasms consisting of mixed epithelial and mesenchymal elements, representing less than 5% of all uterine malignancies. Carcinosarcomas are rare, although the most common cause of uterine cancer-specific death. Few information is available on the pathogenesis, and molecular characterization is poorly investigated. Consequently, the treatment has not changed over the last years and is far too being tailored, consisting of surgery and traditional chemotherapy and radiotherapy. Molecular characterization of liquid biopsy by circulating tumor DNA (ctDNA)/circulating cell-free DNA (ccfDNA) evaluation in a patient with uterine carcinosarcoma. Here, we describe a case report of an 83-year-old woman with carcinosarcomas, stage T3aN0M0. Cancer cells did not express estrogen nor progesterone receptors, while p53 and p16 were positive. Molecular characterization of ccfDNA and of ctDNA was performed by quantitative PCR, amplification-refractory mutation system technology. The presence of phosphatidylInositol-4,5-bisphosphate 3-Kinase catalytic subunit alpha p.E545A mutation was detected in plasma. This approach may suggest the use of liquid biopsy and the development of specific targeted therapy for precision personalized medicine even in rare carcinosarcomas.

Immune Checkpoint Inhibitors in the Treatment of Renal Cancer: Current State and Future Perspective.

Systemic treatment of renal cancer (RCC) has undergone remarkable changes over the past 20 years with the introduction of immunotherapeutic agents targeting programmed cell death (PD-1)/programmed death-ligand 1 (PD-L1) axis, as a single-agent or combined with anti-CTLA-4 monoclonal antibodies (MoAbs) or a multi-target vascular endothelial growth factor-(VEGF) tyrosine kinase inhibitor (TKI). In this paper, we review the main evidence on the use of Immune Checkpoint Inhibitors (ICIs) for RCC treatment from the first demonstration of activity of a nivolumab single agent in a phase I trial to the novel combination strategies (anti-PD-1 plus anti-CTLA4 or anti-PD-1 plus TKI). In addition, we discuss the use of anti-PD-1/PD-L1 agents in patients with non-clear cells and rare histological subtype RCC. Then, we critically examine the current findings in biomarkers that have been proposed to be prognostic or predictive to the response of immunotherapy including immune gene expression signature, B7-H1 expression, PBRM1 loss of function, PD-L1 expression, frame shift indel count, mutations in bromodomain-containing genes in patients with MiT family translocation RCC (tRCC), high expression of the T-effector gene signature, and a high myeloid inflammation gene expression pattern. To date, a single biomarker as a predictor of response has not been established. Since the dynamic behavior of the immune response and the different impact of ICI treatment on patients with specific RCC subtypes, the integration of multiple biomarkers and further validation in clinical trials are needed.

Structural and solution chemistry, antiproliferative effects, and serum albumin binding of three pseudohalide derivatives of auranofin.

Three pseudohalide analogues of the established gold drug auranofin (AF hereafter), of general formula Au(PEt3)X, i.e. Au(PEt3)CN, Au(PEt3)SCN and Au(PEt3)N3 (respectively denoted as AFCN, AFSCN and AFN3), were prepared and characterized. The crystal structure was solved for Au(PEt3)SCN highlighting the classical linear geometry of the 2-coordinate gold(I) center. The solution behaviour of the compounds was then comparatively analysed through 31PNMR providing evidence for an acceptable stability under physiological-like conditions. Afterward, the reaction of these gold compounds with bovine serum albumin (BSA) and consequent adduct formation was investigated by 31PNMR. For all the studied gold compounds, the [Au(PEt3)]+ moiety was identified as the reactive species in metal/protein adducts formation. The cytotoxic effects of the complexes were subsequently measured in comparison to AF against a representative colorectal cancer cell line and found to be still relevant and roughly similar in the three cases though far weaker than those of AF. These results show that the nature of the anionic ligand can modulate importantly the pharmacological action of the gold-triethylphosphine moiety, affecting the cytotoxic potency. These aspects may be further explored to improve the pharmacological profiles of this family of metal complexes.

Correction to: Structural and solution chemistry, antiproliferative effects, and serum albumin binding of three pseudohalide derivatives of auranofin.

In the initial online publication, the given name of the first author was incorrectly displayed and should have read Damiano. The original article has been corrected and the proper representation of the authors' names and their affiliation is also listed here.

The combined activation of KCa3.1 and inhibition of Kv11.1/hERG1 currents contribute to overcome Cisplatin resistance in colorectal cancer cells.

BACKGROUND: Platinum-based drugs such as Cisplatin are commonly employed for cancer treatment. Despite an initial therapeutic response, Cisplatin treatment often results in the development of chemoresistance. To identify novel approaches to overcome Cisplatin resistance, we tested Cisplatin in combination with K+ channel modulators on colorectal cancer (CRC) cells. METHODS: The functional expression of Ca2+-activated (KCa3.1, also known as KCNN4) and voltage-dependent (Kv11.1, also known as KCNH2 or hERG1) K+ channels was determined in two CRC cell lines (HCT-116 and HCT-8) by molecular and electrophysiological techniques. Cisplatin and several K+ channel modulators were tested in vitro for their action on K+ currents, cell vitality, apoptosis, cell cycle, proliferation, intracellular signalling and Platinum uptake. These effects were also analysed in a mouse model mimicking Cisplatin resistance. RESULTS: Cisplatin-resistant CRC cells expressed higher levels of KCa3.1 and Kv11.1 channels, compared with Cisplatin-sensitive CRC cells. In resistant cells, KCa3.1 activators (SKA-31) and Kv11.1 inhibitors (E4031) had a synergistic action with Cisplatin in triggering apoptosis and inhibiting proliferation. The effect was maximal when KCa3.1 activation and Kv11.1 inhibition were combined. In fact, similar results were produced by Riluzole, which is able to both activate KCa3.1 and inhibit Kv11.1. Cisplatin uptake into resistant cells depended on KCa3.1 channel activity, as it was potentiated by KCa3.1 activators. Kv11.1 blockade led to increased KCa3.1 expression and thereby stimulated Cisplatin uptake. Finally, the combined administration of a KCa3.1 activator and a Kv11.1 inhibitor also overcame Cisplatin resistance in vivo. CONCLUSIONS: As Riluzole, an activator of KCa3.1 and inhibitor of Kv11.1 channels, is in clinical use, our results suggest that this compound may be useful in the clinic to improve Cisplatin efficacy and overcome Cisplatin resistance in CRC.