ABSTRACT
A 7-year-old girl presented with painful genital enlargement, which was first believed to be clitoromegaly of hormonal origin. However, on the physical exam the clitoris was not visible and the prepuce and labia minora were enlarged and tender. Magnetic resonance imaging demonstrated an infiltrative abnormal signal with restricted diffusion involving the enlarged clitoris and adjacent soft tissues of the prepuce and labia minora, confirming a nonhormonal infiltrative malignancy. The same abnormal signal was present in enlarged inguinal lymph nodes, the kidneys, and an anterior mediastinal mass. The pathologic diagnosis was T-cell acute lymphoblastic leukemia.
Subject(s)
Lymphadenitis/etiology , Mediastinal Diseases/microbiology , Mediastinum/pathology , Nocardia Infections/complications , Aftercare , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Drug Therapy, Combination , Endoscopic Ultrasound-Guided Fine Needle Aspiration/methods , Humans , Linezolid/administration & dosage , Linezolid/therapeutic use , Lymphadenitis/pathology , Male , Mediastinal Diseases/diagnostic imaging , Middle Aged , Nocardia/isolation & purification , Nocardia Infections/drug therapy , Positron Emission Tomography Computed Tomography/methods , Treatment Outcome , Trimethoprim, Sulfamethoxazole Drug Combination/administration & dosage , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic useABSTRACT
Despite the known importance of androgen receptor (AR) signaling in prostate cancer, the processes downstream of AR that drive disease development and progression remain poorly understood. This knowledge gap has thus limited the ability to treat cancer. Here, it is demonstrated that androgens increase the metabolism of glutamine in prostate cancer cells. This metabolism was required for maximal cell growth under conditions of serum starvation. Mechanistically, AR signaling promoted glutamine metabolism by increasing the expression of the glutamine transporters SLC1A4 and SLC1A5, genes commonly overexpressed in prostate cancer. Correspondingly, gene expression signatures of AR activity correlated with SLC1A4 and SLC1A5 mRNA levels in clinical cohorts. Interestingly, MYC, a canonical oncogene in prostate cancer and previously described master regulator of glutamine metabolism, was only a context-dependent regulator of SLC1A4 and SLC1A5 levels, being unable to regulate either transporter in PTEN wild-type cells. In contrast, rapamycin was able to decrease the androgen-mediated expression of SLC1A4 and SLC1A5 independent of PTEN status, indicating that mTOR complex 1 (mTORC1) was needed for maximal AR-mediated glutamine uptake and prostate cancer cell growth. Taken together, these data indicate that three well-established oncogenic drivers (AR, MYC, and mTOR) function by converging to collectively increase the expression of glutamine transporters, thereby promoting glutamine uptake and subsequent prostate cancer cell growth.Implications: AR, MYC, and mTOR converge to increase glutamine uptake and metabolism in prostate cancer through increasing the levels of glutamine transporters. Mol Cancer Res; 15(8); 1017-28. ©2017 AACR.
