Colorectal cancer primarily metastasizes to the liver and globally kills over 600,000 people annually. By functionally screening 661 microRNAs (miRNAs) in parallel during liver colonization, we have ...identified miR-551a and miR-483 as robust endogenous suppressors of liver colonization and metastasis. These miRNAs convergently target creatine kinase, brain-type (CKB), which phosphorylates the metabolite creatine, to generate phosphocreatine. CKB is released into the extracellular space by metastatic cells encountering hepatic hypoxia and catalyzes production of phosphocreatine, which is imported through the SLC6A8 transporter and used to generate ATP—fueling metastatic survival. Combinatorial therapeutic viral delivery of miR-551a and miR-483-5p through single-dose adeno-associated viral (AAV) delivery significantly suppressed colon cancer metastasis, as did CKB inhibition with a small-molecule inhibitor. Importantly, human liver metastases express higher CKB and SLC6A8 levels and reduced miR-551a/miR-483 levels relative to primary tumors. We identify the extracellular space as an important compartment for malignant energetic catalysis and therapeutic targeting.
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•miR-551a and miR-483-5p suppress colon cancer metastasis by targeting CKB•CKB promote metastatic survival by modulating intra- and extracellular energetics•miRNAs and CKB can be therapeutically targeted by AAV and small molecule delivery
The tumor microenvironment is a rich source of metabolic substrates that could be utilized by cancer cells. Colon cancer cells secrete a kinase that acts extracellularly to generate one such metabolite, phosphocreatinine, that directly fuels tumor growth and metastasis to the liver.
Colorectal cancer (CRC) is a major cause of human death. Mortality is primarily due to metastatic organ colonization, with the liver being the main organ affected. We modeled metastatic CRC (mCRC) ...liver colonization using patient-derived primary and metastatic tumor xenografts (PDX). Such PDX modeling predicted patient survival outcomes. In vivo selection of multiple PDXs for enhanced metastatic colonization capacity upregulated the gluconeogenic enzyme PCK1, which enhanced liver metastatic growth by driving pyrimidine nucleotide biosynthesis under hypoxia. Consistently, highly metastatic tumors upregulated multiple pyrimidine biosynthesis intermediary metabolites. Therapeutic inhibition of the pyrimidine biosynthetic enzyme DHODH with leflunomide substantially impaired CRC liver metastatic colonization and hypoxic growth. Our findings provide a potential mechanistic basis for the epidemiologic association of anti-gluconeogenic drugs with improved CRC metastasis outcomes, reveal the exploitation of a gluconeogenesis enzyme for pyrimidine biosynthesis under hypoxia, and implicate DHODH and PCK1 as metabolic therapeutic targets in CRC metastatic progression.
Drug resistance is a major obstacle to the treatment of most human tumors. In this study, we find that dual-specificity phosphatase 16 (DUSP16) regulates resistance to chemotherapy in nasopharyngeal ...carcinoma, colorectal cancer, gastric and breast cancer. Cancer cells expressing higher DUSP16 are intrinsically more resistant to chemotherapy-induced cell death than cells with lower DUSP16 expression. Overexpression of DUSP16 in cancer cells leads to increased resistance to cell death upon chemotherapy treatment. In contrast, knockdown of DUSP16 in cancer cells increases their sensitivity to treatment. Mechanistically, DUSP16 inhibits JNK and p38 activation, thereby reducing BAX accumulation in mitochondria to reduce apoptosis. Analysis of patient survival in head & neck cancer and breast cancer patient cohorts supports DUSP16 as a marker for sensitivity to chemotherapy and therapeutic outcome. This study therefore identifies DUSP16 as a prognostic marker for the efficacy of chemotherapy, and as a therapeutic target for overcoming chemoresistance in cancer.
Overexpression of phosphatase of regenerating liver (PRL)-3 is associated with the progression of diverse human cancers. We show that the overexpression of PRL-3 protein is not directly associated ...with its transcript levels, indicating the existence of an underlying posttranscriptional regulation. The 5′ untranslanted region (UTR) of PRL-3 mRNA possesses triple GCCCAG motifs capable of suppressing mRNA translation through interaction with PolyC-RNA-binding protein 1 (PCBP1), which retards PRL-3 mRNA transcript incorporation into polyribosomes. Overexpression of PCBP1 inhibits PRL-3 expression and inactivates AKT, whereas knockdown of PCBP1 causes upregulation of PRL-3 protein levels, activation of AKT, and promotion of tumorigenesis. An inverse correlation between protein levels of PRL-3 and PCBP1 in human primary cancers supports the clinical relevance.
► PRL-3 protein is upregulated in diverse human cancers ► PCBP1 suppresses PRL-3 translation via the 5′ UTR of the PRL-3 mRNA ► PCBP1 and PRL-3 protein levels were inversely correlated in human cancers ► The axis of PCBP1→PRL-3→AKT pathway in cancer cell signaling
Colorectal cancer (CRC) is a leading cause of cancer mortality. Creatine metabolism was previously shown to critically regulate colon cancer progression. We report that RGX-202, an oral ...small-molecule SLC6A8 transporter inhibitor, robustly inhibits creatine import in vitro and in vivo, reduces intracellular phosphocreatine and ATP levels, and induces tumor apoptosis. RGX-202 suppressed CRC growth across KRAS wild-type and KRAS mutant xenograft, syngeneic, and patient-derived xenograft (PDX) tumors. Antitumor efficacy correlated with tumoral expression of creatine kinase B. Combining RGX-202 with 5-fluorouracil or the DHODH inhibitor leflunomide caused regressions of multiple colorectal xenograft and PDX tumors of distinct mutational backgrounds. RGX-202 also perturbed creatine metabolism in patients with metastatic CRC in a phase 1 trial, mirroring pharmacodynamic effects on creatine metabolism observed in mice. This is, to our knowledge, the first demonstration of preclinical and human pharmacodynamic activity for creatine metabolism targeting in oncology, thus revealing a critical therapeutic target.
Inter-patient and intra-tumour heterogeneity (ITH) have prompted the need for a more personalised approach to cancer therapy. Although patient-derived xenograft (PDX) models can generate drug ...response specific to patients, they are not sustainable in terms of cost and time and have limited scalability. Tumour Organ-on-Chip (OoC) models are
in vitro
alternatives that can recapitulate some aspects of the 3D tumour microenvironment and can be scaled up for drug screening. While many tumour OoC systems have been developed to date, there have been limited validation studies to ascertain whether drug responses obtained from tumour OoCs are comparable to those predicted from patient-derived xenograft (PDX) models. In this study, we established a multiplexed tumour OoC device, that consists of an 8 × 4 array (32-plex) of culture chamber coupled to a concentration gradient generator. The device enabled perfusion culture of primary PDX-derived tumour spheroids to obtain dose-dependent response of 5 distinct standard-of-care (SOC) chemotherapeutic drugs for 3 colorectal cancer (CRC) patients. The
in vitro
efficacies of the chemotherapeutic drugs were rank-ordered for individual patients and compared to the
in vivo
efficacy obtained from matched PDX models. We show that quantitative correlation analysis between the drug efficacies predicted
via
the microfluidic perfusion culture is predictive of response in animal PDX models. This is a first study showing a comparative framework to quantitatively correlate the drug response predictions made by a microfluidic tumour organ-on-chip (OoC) model with that of PDX animal models.
Colorectal cancer metastasis to the liver is a major cause of cancer-related death; however, the genes and pathways that govern this metastatic colonization event remain poorly characterized. Here, ...using a large-scale in vivo RNAi screen, we identified liver and red blood cell pyruvate kinase (PKLR) as a driver of metastatic liver colonization. PKLR expression was increased in liver metastases as well as in primary colorectal tumors of patients with metastatic disease. Evaluation of a murine liver colonization model revealed that PKLR promotes cell survival in the tumor core during conditions of high cell density and oxygen deprivation by increasing glutathione, the primary endogenous antioxidant. PKLR negatively regulated the glycolytic activity of PKM2, the major pyruvate kinase isoenzyme known to regulate cellular glutathione levels. Glutathione is critical for metastasis, and we determined that the rate-limiting enzyme of glutathione synthesis, GCLC, becomes overexpressed in patient liver metastases, promotes cell survival under hypoxic and cell-dense conditions, and mediates metastatic liver colonization. RNAi-mediated inhibition of glutathione synthesis impaired survival of multiple colon cancer cell lines, and pharmacological targeting of this metabolic pathway reduced colonization in a primary patient-derived xenograft model. Our findings highlight the impact of metabolic reprogramming within the niche as metastases progress and suggest clinical potential for targeting this pathway in colorectal cancer.
Metastatic colonization is the primary cause of death from colorectal cancer (CRC). We employed genome-scale in vivo short hairpin RNA (shRNA) screening and validation to identify 26 promoters of CRC ...liver colonization. Among these genes, we identified a cluster that contains multiple targetable genes, including ITPR3, which promoted liver-metastatic colonization and elicited similar downstream gene expression programs. ITPR3 is a caffeine-sensitive inositol 1,4,5-triphosphate (IP3) receptor that releases calcium from the endoplasmic reticulum and enhanced metastatic colonization by inducing expression of RELB, a transcription factor that is associated with non-canonical NF-κB signaling. Genetic, cell biological, pharmacologic, and clinical association studies revealed that ITPR3 and RELB drive CRC colony formation by promoting cell survival upon substratum detachment or hypoxic exposure. RELB was sufficient to drive colonization downstream of ITPR3. Our findings implicate the ITPR3/calcium/RELB axis in CRC metastatic colony formation and uncover multiple clinico-pathologically associated targetable proteins as drivers of CRC metastatic colonization.
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•Loss of ITPR3 in colorectal cancer cells inhibits metastatic liver colonization•RELB acts downstream of ITPR3/calcium to promote colorectal cancer liver metastasis•ITPR3 and RELB regulate survival in response to hypoxia and substratum detachment•Exposure of colorectal cancer cells to ITPR3 inhibitor caffeine reduces liver metastasis
Moy et al. define a clinically relevant pathway that promotes colorectal cancer cell survival and liver metastasis via the type 3 inositol 1,4,5-triphosphate receptor ITPR3, a calcium channel that controls calcium release from the endoplasmic reticulum, and RELB, a transcription factor that is associated with non-canonical NF-κB signaling.
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