Table 1.

The most positively correlated miRNAs and their known functions in human cancers, including bladder cancer, if such a function was reported.

miRNA	Function	References
hsa-miR-21	Impact on survival and prognosis in patients with pancreatic cancer; exosomal miR-21 promotes proliferation, but also invasion and therapy resistance of colon adenocarcinoma cells via its target PDCD4; nothing is known about its role in bladder cancer; a lack of miR-21 expression in tumor-associated macrophages (TAMs) promotes antitumoral immune response.	[28,29,30]
hsa-miR-29a	Downregulated in bladder cancer; shows inhibition of proliferation in bladder cancer cell lines via PI3K-AKT pathway; acts as a tumour suppressor in many cancer types; increased urine levels correlated with shorter event-free survival in most cancer types; high expression of miR-29a was associated with a prolonged disease-free survival.	[31,32,33,34,35]
hsa-miR-100	Suggested role in the invasion and metastasis of hepatocellular carcinoma; involved in the PI3K/AKT and mTOR pathways in renal carcinoma; interestingly, a variant in the miR-100 gene is a protective factor of childhood acute lymphoblastic leukaemia.	[36,37,38]
hsa-miR-125b	Suppresses cell proliferation and metastasis by targeting the HAX-1 gene in esophageal squamous cell carcinoma; regulates IL-1β-induced inflammatory genes through targeting TRAF6-mediated MAPKs and NF-κB signaling in human osteoarthritic chondrocytes; acts as an oncogene in glioblastoma cells and inhibits cell apoptosis through p53 and p38MAPK-independent pathways; has a role in conferring the metastatic phenotype among pancreatic cancer cells; unknown function in bladder cancer.	[NO_PRINTED_FORM][39,40,41,42]
hsa-miR-142	Linked to the reduced regulatory T-cell function in granulomatosis; suppresses cell proliferation and cell migration in bladder cancer.	[25,26]
hsa-miR-146a	Mediates the suppression of inflammatory response in adipocytes; involved in bladder cancer relapse; important for the maintenance of breast cancer stem cells during EMT; suggested that the urine levels might be possibly used as a prognostic marker for bladder cancer; in bladder cancer, it is usually upregulated, and this event is correlated with the inhibitory effect on the invasion of cancer cells resulting from the reduction of MMP2 expression.	[20,21,22,23,24,25]
hsa-miR-150	Acts as a tumour promoter: promotes cell proliferation, migration and invasion of cancer cells through targeting PDCD4 (programmed cell death 4 protein); modulates cisplatin chemosensitivity and invasiveness of muscle-invasive bladder cancer cells via targeting PDCD4; is suggested as a urinary biomarker for bladder cancer progression; its agonist promotes fibrosis in cultured kidney cells, while its antagonists decrease pro-inflammatory cytokines and pro-fibrotic proteins and increase anti-fibrotic protein SOCS1.	[43,44,45,46,47]
hsa-miR-155	Tumour-promoting and highly oncogenic microRNA that targets ELK3 transcription factor functioning in the hypoxia response; upregulated in breast cancer and linked to PARP-1 inhibitors response; overexpressed in bladder cancer, promoting tumour growth by repressing DMTF1.	[17,18,19]
hsa-miR-199a	Functions as a tumour suppressor in oral squamous cell carcinoma, targeting the IKKβ/NF-κB signalling pathway; inhibits malignant progression of lung cancer through mediating RGS17; serum levels were suggested as a potential diagnostic biomarker for detection of colorectal cancer; recently discovered to inhibit angiogenesis by targeting the VEGF/PI3K/AKT signalling pathway in an in vitro model of diabetic retinopathy; can attenuate aerobic glycolysis and cell proliferation in glioblastoma, but the role in bladder cancer remains unrevealed.	[48,49,50,51,52] [NO_PRINTED_FORM]
hsa-miR-199b	Downregulated in breast cancer patients; is often associated with malignant clinical characteristics; exerts tumour suppressive functions in hepatocellular carcinoma by targeting JAG1 directly; suppression of miR-199b expressions improves apoptosis and reduces the cell viability in cervical cancer.	[53,54,55,56]
hsa-miR-221	High expression is a poor predictor for glioma; affects proliferation and apoptosis of gastric cancer cells (through targeting SOCS3); promotes cisplatin resistance in osteosarcoma cells by targeting PPP2R2A; the function in bladder cancer is unknown.	[57,58,59]
hsa-miR-223	Tumour-suppressive, but also oncogenic miR in various cancers; targets WDR62 directly in bladder cancer—the knockdown of WDR62 in mice significantly inhibited tumour aggressiveness and induced the apoptosis of bladder cancer cells; it may also inhibit migration and invasion of bladder cancer cells.	[60,61,62,63,64]
hsa-miR-511	circZFR promotes cell proliferation and migration by regulating the miR-511/AKT1 pathway in hepatocellular carcinoma; promotes proliferation of human hepatoma cells; functions as a tumour suppressor and a prognostic marker in colorectal cancer; contributes to intestinal inflammation; significantly altered expression and its target AKT3 have negative prognostic value in prostate cancer, but its function in bladder cancer remains unknown.	[65,66,67,68,69]
hsa-miR-4772	Significance in bladder cancer and immunological surveillance remains unclear, but a high level in serum exosomes derived from stage II and stage III colon cancer patients was negatively associated with the risk of recurrence and the risk of death.	[70,71]
hsa-miR-5586	Downregulated in pancreatic and bladder cancers; high levels linked to good outcomes in diffuse large B-cell lymphoma (DLBCL); significance in bladder cancer and immunological surveillance remains unknown.	[72,73]
hsa-miR-7702	Potentially important in colorectal cancer (CRC) progression, but significance in bladder cancer remains unclear.	[74,75]