PubMed · 7176751
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
F J Laso, M González Díaz, J I Paz, M C Cañizo, A Ríos, S de Castro. [Bone marrow necrosis].. https://pubmed.ncbi.nlm.nih.gov/7176751/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The G12 subfamily of heterotrimeric G proteins, comprised of the alpha-subunits Galpha12 and Galpha13, has been implicated as a signaling component in cellular processes ranging from cytoskeletal changes to cell growth and oncogenesis. In an attempt to elucidate specific roles of this subfamily in cell regulation, we sought to identify molecular targets of Galpha12. Here we show a specific interaction between the G12 subfamily and the cytoplasmic tails of several members of the cadherin family of cell-surface adhesion proteins. Galpha12 or Galpha13 binding causes dissociation of the transcriptional activator beta-catenin from cadherins. Furthermore, in cells lacking the adenomatous polyposis coli protein required for beta-catenin degradation, expression of mutationally activated Galpha12 or Galpha13 causes an increase in beta-catenin-mediated transcriptional activation. These findings provide a potential molecular mechanism for the previously reported cellular transforming ability of the G12 subfamily and reveal a link between heterotrimeric G proteins and cellular processes controlling growth and differentiation.
BACKGROUND: Antioxidant enzymes (AEs), which catalyze the conversion of reactive oxygen species (ROS) to water, include catalase (CAT), manganese-containing superoxide dismutase (MnSOD), and copper and zinc-containing superoxide dismutase (CuZnSOD). Previous work has indicated that MnSOD, CAT, and CuZnSOD levels are nearly always low in cancer cells. METHODS: Formalin-fixed, paraffin-embedded tissue from 31 radical prostatectomy specimens was immunohistochemically stained with polyclonal antibodies to CAT, MnSOD, and CuZnSOD. RESULTS: Malignant glands are typically stained with less intensity than benign/ hyperplastic glands. Marked heterogeneity of staining intensity was seen in the malignant glands for each of the three enzymes. A similar, though less marked, spectrum of heterogeneity of staining intensity was observed in the benign/hyperplastic epithelium contained in the specimens. No statistically significant correlation was found between intensity of staining for any of the three antioxidant enzymes and Gleason score, tumor stage, or preoperative prostate-specific antigen (PSA). CONCLUSIONS: Cellular levels of CAT, MnSOD, and CuZnSOD in prostatic adenocarcinoma reveal that many tumors appear to have decreased levels of expression. The finding that malignant prostate epithelium may have lowered expression of AEs suggests that further study of the role of AEs in malignant transformation in the prostate is warranted.
BACKGROUND: Metastatic involvement of the pituitary gland is a very unusual presentation of prostatic cancer. We report a favorable response to medical treatment in such a patient. METHODS AND RESULTS: A 77-year-old man presented with blindness, ophthalmoplegia in his left eye, and mild impairment of memory and mental status. Neuroradiological studies showed a huge intra- and suprasellar lesion that destroyed the sellar floor and extended into the sphenoid sinus. Transsphenoidal biopsy of the lesion demonstrated a prostatic adenocarcinoma. Postoperative studies revealed an enlarged prostate gland and multiple lytic bone lesions. The patient was treated with a combination of leuprolide acetate plus flutamide. Four months later, the patient exhibited a marked improvement in his neurologic status and regained vision in the right eye (visual acuity 6/20). Repeat magnetic resonance imaging of the sellar region confirmed a striking shrinkage of the prostatic metastasis. The clinical status remained stable for 22 months, after which time the disease progressed and the patient died 25 months after beginning treatment. CONCLUSIONS: A favorable response to combined androgen blockade suggests that medical therapy should be considered the therapy of first choice when surgical removal of the metastatic lesion in the pituitary is impossible or too risky.