scholarly journals Inhibition of Scavenger Receptor Class B Type 1 (SR-B1) Expression and Activity as a Potential Novel Target to Disrupt Cholesterol Availability in Castration-Resistant Prostate Cancer

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1509
Author(s):  
Mitali Pandey ◽  
Grace Cuddihy ◽  
Jacob A. Gordon ◽  
Michael E. Cox ◽  
Kishor M. Wasan

There have been several studies that have linked elevated scavenger receptor class b type 1 (SR-B1) expression and activity to the development and progression of castration-resistant prostate cancer (CRPC). SR-B1 facilitates the influx of cholesterol to the cell from lipoproteins in systemic circulation. This influx of cholesterol may be important for many cellular functions, including the synthesis of androgens. Castration-resistant prostate cancer tumors can synthesize androgens de novo to supplement the loss of exogenous sources often induced by androgen deprivation therapy. Silencing of SR-B1 may impact the ability of prostate cancer cells, particularly those of the castration-resistant state, to maintain the intracellular supply of androgens by removing a supply of cholesterol. SR-B1 expression is elevated in CRPC models and has been linked to poor survival of patients. The overarching belief has been that cholesterol modulation, through either synthesis or uptake inhibition, will impact essential signaling processes, impeding the proliferation of prostate cancer. The reduction in cellular cholesterol availability can impede prostate cancer proliferation through both decreased steroid synthesis and steroid-independent mechanisms, providing a potential therapeutic target for the treatment of prostate cancer. In this article, we discuss and highlight the work on SR-B1 as a potential novel drug target for CRPC management.

2020 ◽  
Vol 295 (24) ◽  
pp. 8252-8261 ◽  
Author(s):  
C. Alicia Traughber ◽  
Emmanuel Opoku ◽  
Gregory Brubaker ◽  
Jennifer Major ◽  
Hanxu Lu ◽  
...  

High-density lipoprotein (HDL) metabolism is facilitated in part by scavenger receptor class B, type 1 (SR-B1) that mediates HDL uptake into cells. Higher levels of HDL have been associated with protection in other diseases, however, its role in prostate cancer is not definitive. SR-B1 is up-regulated in prostate cancer tissue, suggesting a possible role of this receptor in tumor progression. Here, we report that knockout (KO) of SR-B1 in both human and mouse prostate cancer cell lines through CRISPR/Cas9-mediated genome editing reduces HDL uptake into the prostate cancer cells and reduces their proliferation in response to HDL. In vivo studies using syngeneic SR-B1 WT (SR-B1+/+) and SR-B1 KO (SR-B1−/−) prostate cancer cells in WT and apolipoprotein-AI KO (apoA1-KO) C57BL/6J mice revealed that WT hosts, containing higher levels of total and HDL-cholesterol, grew larger tumors than apoA1-KO hosts with lower levels of total and HDL-cholesterol. Furthermore, SR-B1−/− prostate cancer cells formed smaller tumors in WT hosts than SR-B1+/+ cells in the same host model. Increased tumor volume was overall associated with reduced survival. We conclude that knocking out SR-B1 in prostate cancer tumors reduces HDL-associated increases in prostate cancer cell proliferation and disease progression.


The Prostate ◽  
2011 ◽  
Vol 71 (14) ◽  
pp. 1510-1517 ◽  
Author(s):  
Takeo Kosaka ◽  
Akira Miyajima ◽  
Suguru Shirotake ◽  
Eiji Kikuchi ◽  
Mototsugu Oya

2021 ◽  
Vol 331 ◽  
pp. e128
Author(s):  
N.-A. Azemi ◽  
L. Abu-Bakar ◽  
N. Ismail ◽  
V. Sevakumaran ◽  
T.-S. Tengku-Muhammad

Hepatology ◽  
1997 ◽  
Vol 26 (4) ◽  
pp. 1072-1074 ◽  
Author(s):  
M A Arrese ◽  
J M Crawford

2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 340-340 ◽  
Author(s):  
Riikka Oksala ◽  
Mari Karimaa ◽  
Outi Simola ◽  
Meri Ramela ◽  
Reetta Riikonen ◽  
...  

340 Background: Castration-resistant prostate cancer (CRPC) is a major cause of cancer mortality worldwide. The mechanisms behind the development of resistance are complex and not fully understood; altered androgen synthesis, androgen receptor (AR) overexpression or gene amplification, and mutations have been indentified. However, tumor growth may still be responsive to therapies that can further suppress de novo intratumoral steroid synthesis upstream of CYP17A1. ODM-208 is an oral, non-steroidal and selective inhibitor of CYP11A1 enzyme that suppresses the synthesis of all steroid hormones and their precursors. Methods: The inhibition of CYP11A1 was measured in vitro by the formation of radiolabelled isocapronic acid in a human adrenal cortex cell line (H295R), and further analysing pregnenolone (Preg) and testosterone (T) formation by ELISA. The tumor growth inhibition of ODM-208 alone or in combination with prednisone (Pred) was studied in VCaP CRPC xenograft where also concentrations of main steroid hormones progesterone (P), corticosterone (CORT) and T in tumors and adrenals were analysed. In addition, plasma ACTH and LH levels were measured at the end of the xenograft study. In dogs an ACTH stimulation test was done. Toxicity studies were conducted in rats and dogs. Results: ODM-208 potently inhibits CYP11A1 and synthesis of Preg and T with nM concentrations in vitro. In the VCaP CRPC xenograft ODM-208 alone and in combination with Pred significantly inhibited tumor growth. Concentrations of T, P and CORT were significantly decreased in the adrenals, indicating strong CYP11A1 inhibition. Also, significantly decreased steroid levels in tumors was observedhe Pred combination increased plasma ACTH levels less than ODM-208 alone, whereas no difference was seen in the LH. In dogs ACTH-stimulated cortisol production was significantly inhibited after single oral dose of ODM-208. In toxicological studies ODM-208 showed expected reversible findings in target tissues, mainly related to the pharmacology. Conclusions: ODM-208 shows promising antitumor activity in preclinical CRPC models with favorable toxicological profile. Thus, ODM-208 might have potential for treating the patients with CRPC.


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