Intermittent androgen deprivation therapy (IADT) is an alternative to continuous androgen deprivation therapy (ADT) in prostate cancer patients with nonmetastatic disease. ADT is associated with numerous side effe...Intermittent androgen deprivation therapy (IADT) is an alternative to continuous androgen deprivation therapy (ADT) in prostate cancer patients with nonmetastatic disease. ADT is associated with numerous side effects such as hot flashes, sexual dysfunction, anemia, fatigue, loss of muscle mass, osteoporosis, metabolic syndrome and premature cardiovascular disease. IADT was developed with the intention of improving the quality of life and to delay progression of prostate cancer to castration resistance. The benefits of slightly improved quality of life by IADT compared to ADT were demonstrated in multiple clinical trials. IADT was noted to be noninferior to ADT in patients with biochemical recurrence of prostate cancer but in studies performed in patients with metastatic prostate cancer, the results were inconclusive. Our recent studies suggested that the administration of 5 alpha-reductase inhibitors during the off-cycle of IADT can significantly prolong the survival of mice bearing androgen-sensitive prostate tumors when off-cycle duration was short. This review discusses the survival benefit of 5 alpha-reductase inhibition in IADT in animal models and the potential translation of this finding into clinic.展开更多
The dysregulation of pathways regulat-ing cellular function is a frequent hall-mark of cancer and the development of specific pathway inhibitors that alter tumor growth and progression are the focus of multiple recent...The dysregulation of pathways regulat-ing cellular function is a frequent hall-mark of cancer and the development of specific pathway inhibitors that alter tumor growth and progression are the focus of multiple recent studies. E3 ubiquitin ligases are a large group of diverse protein enzymes that specifically target proteins for dear- ance, and their importance to normal cel-lular function is illustrated in the many diseases associated with their loss of func- tion or inappropriate targeting. S-phase kinase-associated protein 2 (Skp2) is an F box protein that plays critical roles in cell-cycle progression, senescence, metabolism, and acts as an Skpl-Cullin-l-F box (SCF) ubiquitin ligase substrate recognition fac-tor. Overexpression of Skp2 is associated with poor prognosis and metastasis in many cancers and is a well validated drug target. In a recent report, Chart et al. have iden-tified an Skp2 inhibitor that selectively impairs Skp2 E3 ligase activity using an integrated virtual high-throughput drug screening and experimental validation approach. This Skp2 inhibitor restricts cancer stemness and potentiates sensitivity to chemotherapeutic agents in multiple ani-mal tumor models. These findings identify a new novel small molecule that targets the Skp2 and reduces tumor growth by attenu-ating aerobic glycolysis and inducing cel-lular senescence.展开更多
Speckle-type POZ (pox virus and zinc finger protein) protein (SPOP) is anE3 ubiquitin ligase adaptor protein that specifically promotes the ubiquitination and proteasome degradation of proteins. SPOP mutations are...Speckle-type POZ (pox virus and zinc finger protein) protein (SPOP) is anE3 ubiquitin ligase adaptor protein that specifically promotes the ubiquitination and proteasome degradation of proteins. SPOP mutations are frequent in prostate cancer, and in a previous study, An et al. demonstrated that SPOP induced the degradation of the androgen receptor (AR) suggesting that SPOP is important in maintaining prostate homeostasis. In this current highlighted report, An and colleagues showed that ERG, which has been implicated as an oncoprotein in prostate cancer.展开更多
文摘Intermittent androgen deprivation therapy (IADT) is an alternative to continuous androgen deprivation therapy (ADT) in prostate cancer patients with nonmetastatic disease. ADT is associated with numerous side effects such as hot flashes, sexual dysfunction, anemia, fatigue, loss of muscle mass, osteoporosis, metabolic syndrome and premature cardiovascular disease. IADT was developed with the intention of improving the quality of life and to delay progression of prostate cancer to castration resistance. The benefits of slightly improved quality of life by IADT compared to ADT were demonstrated in multiple clinical trials. IADT was noted to be noninferior to ADT in patients with biochemical recurrence of prostate cancer but in studies performed in patients with metastatic prostate cancer, the results were inconclusive. Our recent studies suggested that the administration of 5 alpha-reductase inhibitors during the off-cycle of IADT can significantly prolong the survival of mice bearing androgen-sensitive prostate tumors when off-cycle duration was short. This review discusses the survival benefit of 5 alpha-reductase inhibition in IADT in animal models and the potential translation of this finding into clinic.
文摘The dysregulation of pathways regulat-ing cellular function is a frequent hall-mark of cancer and the development of specific pathway inhibitors that alter tumor growth and progression are the focus of multiple recent studies. E3 ubiquitin ligases are a large group of diverse protein enzymes that specifically target proteins for dear- ance, and their importance to normal cel-lular function is illustrated in the many diseases associated with their loss of func- tion or inappropriate targeting. S-phase kinase-associated protein 2 (Skp2) is an F box protein that plays critical roles in cell-cycle progression, senescence, metabolism, and acts as an Skpl-Cullin-l-F box (SCF) ubiquitin ligase substrate recognition fac-tor. Overexpression of Skp2 is associated with poor prognosis and metastasis in many cancers and is a well validated drug target. In a recent report, Chart et al. have iden-tified an Skp2 inhibitor that selectively impairs Skp2 E3 ligase activity using an integrated virtual high-throughput drug screening and experimental validation approach. This Skp2 inhibitor restricts cancer stemness and potentiates sensitivity to chemotherapeutic agents in multiple ani-mal tumor models. These findings identify a new novel small molecule that targets the Skp2 and reduces tumor growth by attenu-ating aerobic glycolysis and inducing cel-lular senescence.
文摘Speckle-type POZ (pox virus and zinc finger protein) protein (SPOP) is anE3 ubiquitin ligase adaptor protein that specifically promotes the ubiquitination and proteasome degradation of proteins. SPOP mutations are frequent in prostate cancer, and in a previous study, An et al. demonstrated that SPOP induced the degradation of the androgen receptor (AR) suggesting that SPOP is important in maintaining prostate homeostasis. In this current highlighted report, An and colleagues showed that ERG, which has been implicated as an oncoprotein in prostate cancer.