We demonstrate that the transition from a reliance on glycolysis to oxidative phosphorylation in a transformed cell line is dependent on an increase in the levels and activity of sirtuin-3. Sirtuin-3 deacetylates cyclophilin D, diminishing its peptidyl-prolyl cis-trans isomerase activity and inducing its dissociation from the adenine nucleotide translocator. Moreover, the sirtuin-3-induced inactivation of cyclophilin D causes a detachment of hexokinase II from the mitochondria that is necessary for stimulation of oxidative phosphorylation. These results might have important implications for the role of sirtuin-3 in the metabolism of some cancer cells and their susceptibility to mitochondrial injury and cytotoxicity.

No abstract

Perivascular epithelioid cell tumors (PEComas) constitute a rare subset of mesenchymal neoplasms classified by the World Health Organization in 2002. We present two cases of PEComas; the first is a cervical PEComa in a 35-year-old woman with no known past medical history who presented with a palpable pelvic mass; the second is an adnexal PEComa in a 39-year-old woman with a history of colitis who presented with abdominal pain and diarrhea. The rarity of these tumors has led to little information about imaging characteristics which we hope these two cases will help expand.

Background There have been few documented cases of combined primitive neuroectodermal and embryonal rhabdomyosarcomas (ERMS) in the uterus. Due to their rarity, there is no consensus on the optimal treatment for patients with primitive neuroectodermal tumor (PNET) and ERMS of the uterus. Studies on treatment and outcome are limited. Case presentation A 32 year-old female presented with heavy vaginal bleeding. Ultrasound revealed an 18 cm uterus with thickened endometrium. Histopathology revealed embryonal rhabdomyosarcoma. She underwent a total abdominal hysterectomy, bilateral salpingectomy, lymph node dissection, and omentectomy. Pathologic review confirmed a tumor with mainly central-type PNET and focally ERMS within the uterus and cervix. She was treated with adjuvant chemoradiation. Conclusion Treatment of the predominant tumor, PNET, should be the primary goal of therapy. Vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide with tumor directed radiation may be efficacious for the treatment of this specific high grade uterine sarcoma.