Metabolic Modulation of Clear-cell Renal Cell Carcinoma with Dichloroacetate, an Inhibitor of Pyruvate Dehydrogenase Kinase.

BACKGROUND: Clear-cell renal cell carcinoma (ccRCC) exhibits suppressed mitochondrial function and preferential use of glycolysis even in normoxia, promoting proliferation and suppressing apoptosis. ccRCC resistance to therapy is driven by constitutive hypoxia-inducible factor (HIF) expression due to genetic loss of von Hippel-Lindau factor. In addition to promoting angiogenesis, HIF suppresses mitochondrial function by inducing pyruvate dehydrogenase kinase (PDK), a gatekeeping enzyme for mitochondrial glucose oxidation. OBJECTIVE: To reverse mitochondrial suppression of ccRCC using the PDK inhibitor dichloroacetate (DCA). DESIGN, SETTING, AND PARTICIPANTS: Radical nephrectomy specimens from patients with ccRCC were assessed for PDK expression. The 786-O ccRCC line and two animal models (chicken in ovo and murine xenografts) were used for mechanistic studies. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Mitochondrial function, proliferation, apoptosis, HIF transcriptional activity, angiogenesis, and tumor size were measured in vitro and in vivo. Independent-sample t-tests and analysis of variance were used for statistical analyses. RESULTS: PDK was elevated in 786-O cells and in ccRCC compared to normal kidney tissue from the same patient. DCA reactivated mitochondrial function (increased respiration, Krebs cycle metabolites such as α-ketoglutarate [cofactor of factor inhibiting HIF], and mitochondrial reactive oxygen species), increased p53 activity and apoptosis, and decreased proliferation in 786-O cells. DCA reduced HIF transcriptional activity in an FIH-dependent manner, inhibiting angiogenesis in vitro. DCA reduced tumor size and angiogenesis in vivo in both animal models. CONCLUSIONS: DCA can reverse the mitochondrial suppression of ccRCC and decrease HIF transcriptional activity, bypassing its constitutive expression. Its previous clinical use in humans makes it an attractive candidate for translation to ccRCC patients. PATIENT SUMMARY: We show that an energy-boosting drug decreases tumor growth and tumor blood vessels in animals carrying human kidney cancer cells. This generic drug has been used in patients for other conditions and thus could be tested in kidney cancer that remains incurable.

Use of immunohistochemistry in routine workup of prostate needle biopsies: a tertiary academic institution experience.

CONTEXT: Diagnostic use of immunohistochemistry has been extensively studied in prostate needle biopsy, but its use in routine practice and the quality assurance and associated cost have not been previously addressed. OBJECTIVE: To examine the routine use of immunohistochemistry in prostate biopsies in a tertiary academic institution. DESIGN: We reviewed reports of 748 consecutive prostate biopsies and we evaluated the turnaround times, the final diagnosis on individual specimens, the intradepartmental consultation rates, and the associated costs. RESULTS: Immunohistochemistry evaluation was required for 39.4% of biopsies and 12% of blocks (average 1.8 blocks/case). The biopsies with immunohistochemistry were signed out 1.7 workdays later (8.6 versus 6.9 days). The diagnostic breakdown for individual blocks evaluated by immunohistochemistry was Cancer 47.7%; Atypical, Suspicious 10.8%; Small Atypical Glands Adjacent to High-Grade Prostatic Intraepithelial Neoplasia 6.9%; High-Grade Prostatic Intraepithelial Neoplasia 12.4%; and Benign 22.2%. Diagnoses of Cancer or Atypical, Suspicious (Atypical, Suspicious + Small Atypical Glands Adjacent to High-Grade Prostatic Intraepithelial Neoplasia) were rendered in 65.4% of individual blocks assessed by immunohistochemistry. Immunohistochemistry aided in establishing limited cancer (≤10% of core) in 69.3% of cases and in 74% of single-core-positive biopsies. Departmental consultation was performed in 18.3% of biopsies and immunohistochemistry was used in 68% of these cases. Both immunohistochemistry and consultation were performed in 55.8% of Atypical, Suspicious cases. The average immunohistochemistry cost per biopsy was $22.34 and the estimated annual cost for prostate biopsy immunohistochemistry in our laboratory was $33 420.64. CONCLUSIONS: Immunohistochemistry is frequently used in our prostate biopsy practice to establish or confirm a limited Cancer diagnosis, to better resolve diagnostic ambiguity, or for quality assurance. The data provided herein can be used for comparisons with other prostate biopsy practices.

Dehydroepiandrosterone reverses systemic vascular remodeling through the inhibition of the Akt/GSK3-{beta}/NFAT axis.

BACKGROUND: The remodeled vessel wall in many vascular diseases such as restenosis after injury is characterized by proliferative and apoptosis-resistant vascular smooth muscle cells. There is evidence that proproliferative and antiapoptotic states are characterized by a metabolic (glycolytic phenotype and hyperpolarized mitochondria) and electric (downregulation and inhibition of plasmalemmal K(+) channels) remodeling that involves activation of the Akt pathway. Dehydroepiandrosterone (DHEA) is a naturally occurring and clinically used steroid known to inhibit the Akt axis in cancer. We hypothesized that DHEA will prevent and reverse the remodeling that follows vascular injury. METHODS AND RESULTS: We used cultured human carotid vascular smooth muscle cell and saphenous vein grafts in tissue culture, stimulated by platelet-derived growth factor to induce proliferation in vitro and the rat carotid injury model in vivo. DHEA decreased proliferation and increased vascular smooth muscle cell apoptosis in vitro and in vivo, reducing vascular remodeling while sparing healthy tissues after oral intake. Using pharmacological (agonists and antagonists of Akt and its downstream target glycogen-synthase-kinase-3beta [GSK-3beta]) and molecular (forced expression of constitutively active Akt1) approaches, we showed that the effects of DHEA were mediated by inhibition of Akt and subsequent activation of GSK-3beta, leading to mitochondrial depolarization, increased reactive oxygen species, activation of redox-sensitive plasmalemmal voltage-gated K(+) channels, and decreased [Ca(2+)](i). These functional changes were accompanied by sustained molecular effects toward the same direction; by decreasing [Ca(2+)](i) and inhibiting GSK-3beta, DHEA inhibited the nuclear factor of activated T cells transcription factor, thus increasing expression of Kv channels (Kv1.5) and contributing to sustained mitochondrial depolarization. These results were independent of any steroid-related effects because they were not altered by androgen and estrogen inhibitors but involved a membrane G protein-coupled receptor. CONCLUSIONS: We suggest that the orally available DHEA might be an attractive candidate for the treatment of systemic vascular remodeling, including restenosis, and we propose a novel mechanism of action for this important hormone and drug.