The expression of YAP1 is increased in high-grade prostatic adenocarcinoma but is reduced in neuroendocrine prostate cancer.

BACKGROUND: After long-term androgen deprivation therapy, 25-30% prostate cancer (PCa) acquires an aggressive neuroendocrine (NE) phenotype. Dysregulation of YAP1, a key transcription coactivator of the Hippo pathway, has been related to cancer progression. However, its role in neuroendocrine prostate cancer (NEPC) has not been assessed. METHODS: Immunohistochemistry and bioinformatics analysis were conducted to evaluate YAP1 expression levels during PCa initiation and progression. RESULTS: YAP1 expression was present in the basal epithelial cells in benign prostatic tissues, lost in low-grade PCa, but elevated in high-grade prostate adenocarcinomas. Interestingly, the expression of YAP1 was reduced/lost in both human and mouse NEPC. CONCLUSIONS: The expression of YAP1 is elevated in high-grade prostate adenocarcinomas but lost in NEPC.

Renal cell carcinoma with leiomyomatous stroma: a review of an emerging entity distinct from clear cell conventional renal cell carcinoma.

Clear cell renal cell carcinomas accounts for 65 to 75% of all malignant renal tumors. The International Society of Urological Pathology 2012 Vancouver Classification of renal neoplasia and the World Health Organization 2016 Classification of renal tumors have included renal cell carcinoma with leiomyomatous stroma in a category of emerging/provisional entities of renal cell carcinoma. Macroscopically, renal cell carcinomas with leiomyomatous stroma are well circumscribed tumors with a cut surface of gray-white fibrotic tissues. Microscopically, the tumors are composed of nodules and anastomosing tubules of renal cells with clear cytoplasms. The carcinoma cells are embedded in a cellular stroma composed of intertwining bundles of smooth muscle. Immunohistochemically, the neoplastic cells are typically positive for CK7 and CD10 immunomarkers. Biomarkers including CAIX, pankeratin, vimentin, and HIF1-alpha stain positively in many renal cell carcinomas with leiomymomatous stroma. Molecular genetic studies of this variant of tumor reveal no VHL mutation, trisomy 7 or trisomy 17. However, a TCEB1 mutation has been demonstrated in a subset of tumors and rare cases are reported from patients with a family history of tuberous sclerosis. The biological behavior of this variant of tumor is indolent and the prognosis is favorable.

Prostatic adenocarcinoma with novel NTRK3 gene fusion: a case report.

TMPRSS2-ERG gene fusion occurs in approximately 50% of prostatic adenocarcinoma and their expression is associated with aggressive phenotype, higher tumor stage, and tumor metastasis. A case of prostatic adenocarcinoma with IRF2BP2-NTRK1 translocation was previously reported. We report a prostatic adenocarcinoma with novel NTRK3 gene fusion that occurs in a 71-year-old male patient with aggressive histologic phenotype and multiple bony metastases. Prostatic biopsy revealed that there is a prostatic adenocarcinoma with a Gleason score of 9 (4+5), grade group 5, and multiple sites of perineural and ganglional invasion. Fluorescence in-situ hybridization (FISH) and next-generation sequencing were performed. FISH studies showed a breakage within the NTRK3 gene in prostatic adenocarcinoma cells. Next-generation sequencing confirmed that there is a PRPSAP1-NTRK3 translocation in the prostatic adenocarcinoma. In addition, ASXL1, KIF5B, MED12, PIK3CA mutations were found. NTRK alterations or dysregulation of PI3K signaling pathway were found in many types of cancers. TRK inhibitors including larotrectinib and entrectinib were approved by the US Food and Drug Administration for treating TRK fusion-positive malignant tumors and PI3K/AKT/mTOR pathway inhibitors were under clinical studies on various cancers including prostate cancer. In our current case, both NTRK3 and PIK3CA may serve as biomarkers for precision targeted therapy.

Teasing out the best molecular marker in the AKT/mTOR pathway in head and neck squamous cell cancer patients.

OBJECTIVES/HYPOTHESIS: No reliable molecular biomarker is currently available for clinical application in the management of head and neck cancer patients. The AKT/mTOR pathway is activated in 90% to 100% of head and neck squamous cell cancer (HNSCC) and could be promising biomarkers closely linked to cancer incidence. STUDY DESIGN: Retrospective study of HNSCC and non-cancer patients. METHODS: Oral mucosa from noncancer patients were compared to HNSCC tumors and junctional zone mucosa. The candidate biomarkers mTOR, AKT, 4EBP1, and S6 kinase, signaling components upstream and downstream of mTOR that appear dysregulated in HNSCC, were evaluated using immunohistochemistry (IHC) and Western blot analysis. RESULTS: Expression of phosphorylated AKT and phosphorylated mTOR were significantly higher in cancer patient tumors compared to noncancer oral mucosa samples (P = .004 and P = .026, respectively) by Western blot analysis. Expression of p-mTOR and p-4EBP1 were higher in patient junctional zones compared to tumors (p = 0.017 and p = 0.022, respectively) and no difference in p-AKT or p-S6 expression in HNSCC patients' junctional zone compared to tumors. IHC-demonstrated p-mTOR expression was 81.9% sensitive and 100% specific in differentiating cancer from noncancer mucosa, whereas p-4EBP1 expression by IHC was only 50.0% sensitive and 95.5% specific in differentiating normal mucosa from HNSCC (P < .01). CONCLUSIONS: Phosphorylated mTOR appears to be a reliable biomarker by both Western blot analysis (P = .026) and IHC in human head and neck cancer (P < .001). Moreover, phosphorylated AKT, which is immediately upstream of mTOR, is a potential biomarker that should be further studied. Clinical trials with mTOR inhibitors are being evaluated for HNSCC, and selecting patients that are likely to respond to these inhibitors requires identifying and validating predictive biomarkers of response.

Severe autoimmune hypoglycemia with insulin antibodies necessitating plasmapheresis.

OBJECTIVE: To report a case of autoimmune hypoglycemia. METHODS: We describe the clinical course of a patient with autoimmune hypoglycemia, including results of biochemical and histocompatibility antigen studies, as well as the therapeutic intervention and follow-up. RESULTS: A 77-year-old man presented with clinical manifestations of severe spontaneous hypoglycemia associated with extremely high levels of insulin (>300 mU/mL) and insulin antibodies (>100 U/mL) without any exogenous insulin administration. He had no other associated autoimmune disorder or exposure to the sulfhydryl group of drugs. Corticosteroid therapy was initiated, but the patient continued to have hypoglycemia and required plasmapheresis. The hypoglycemia resolved after plasmapheresis. During follow-up, the patient was treated with prednisone, the dose of which was tapered gradually. The insulin antibodies, which had decreased rapidly after plasmapheresis, gradually disappeared within a few months. The patient remained free of hypoglycemia as well as insulin antibodies 11 months after corticosteroid therapy was discontinued. CONCLUSION: Although autoimmune hypoglycemia is an uncommon disorder, it should be considered in any patient with hypoglycemia in the setting of nonsuppressed insulin levels associated with insulin antibodies.