Allow Aloe to Do the Work: Aloe vera Constrains Growth of Bladder Cancer Cells and Modulates Expression of Key...

Bladder cancer is one of the most common urological malignancies, with 5-year survival rates below 40% in advanced cases. Oncologic immunotherapy has become a popular approach to treating cancer and programmed death ligand 1 (PDL1), programmed death ligand 2 (PDL2), intercellular adhesion molecule 2 (ICAM2) and 4-1BB ligand (4-1BBL) are key costimulatory molecules in oncologic immunotherapy. Previous research has shown plant phytochemicals can act as immunomodulators by regulating costimulatory functions to increase T-cell activation and thus to inhibit malignant proliferation. However, the role of Aloe vera in the growth of bladder cancer and in the expression of these key costimulatory molecules has not been elucidated yet. This study is designed to investigate if Aloe vera could have a role in the growth of bladder cancer and if it has any effect on the expression of these key costimulatory molecules in bladder cancer.

Clonogenic survival assay and immunohistochemistry (IHC) for PCNA staining were used to evaluate growth of a widely used bladder cancer cell line, T24, in the presence or absence of Aloe vera extract (AE). RT-PCR and IHC were performed to investigate the expression of important costimulatory molecules PDL1, PDL2, ICAM2, and 4-1BBL.

Clonogenic survival assay showed a reduction in the percentage of bladder cancer cell colonies, and this result was supported by decreased PCNA staining intensity upon treatment with AE. RT-PCR revealed decreased expression levels of PDL1 and PDL2, which are pro-oncogenic costimulatory molecules and increased expression levels of ICAM2 and 4-1BBL, which are anti-oncogenic costimulatory molecules. Their expression levels were further supported by IHC staining.

Aloe vera inhibits bladder cancer growth. Aloe vera upregulates the expression of ICAM2 and 4-1BBL and downregulates the expression of PDL1 and PDL2.