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Yu, Jane, Aristotelis Astrinidis, Sharon Howard, and Elizabeth Petri Henske. Estradiol and tamoxifen stimulate LAM-associated angiomyolipoma cell growth and activate both genomic and nongenomic signaling pathways. Am J Physiol Lung Cell Mol Physiol 286: L694-L700, 2004. First published August 15, 2003; 10.1152/ ajplung.00204.2003.--Lymphangioleiomyomatosis (LAM) is a progressive lung disease affecting almost exclusively women. The reasons for this strong gender predisposition are poorly understood. Renal angiomyolipomas occur in 50-60% of sporadic LAM patients. The smooth muscle cells of pulmonary LAM and renal angiomyolipomas are nearly indistinguishable morphologically. Here, we report the first successful cell culture of a LAM-associated renal angiomyolipoma. The cells carried inactivating mutations in both alleles of the TSC2 gene and expressed estrogen receptor [alpha], estrogen receptor [beta], and androgen receptor. To elucidate the cellular pathways through which steroid hormones influence LAM pathogenesis, we treated the cells with both estradiol and tamoxifen. Cell growth was stimulated by estradiol, associated with phosphorylation of p44/42 MAPK at 5 min and an increase in c-myc expression at 4 h. Tamoxifen citrate also stimulated cell growth, associated with increased phosphorylation of p44/42 MAPK and expression of c-myc, indicating that tamoxifen has agonist effects on angiomyolipoma cells. This response to tamoxifen in human angiomyolipoma cells differs from prior studies of Eker rat leiomyoma cells, possibly reflecting cell type or species differences in cells lacking tuberin. Our data provide the first evidence that estradiol stimulates the growth of angiomyolipoma cells, that tamoxifen has agonist effects in angiomyolipoma cells, and that estradiol and tamoxifen impact both genomic and nongenomic signaling pathways in angiomyolipoma cells. The responsiveness of angiomyolipoma cells to estradiol may be related to the underlying reasons that LAM affects primarily women. tuberous sclerosis complex; mitogen-activated protein kinase; tuberin; hamartin: estrogen receptor; lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a progressive lung disease affecting almost exclusively women. The reasons for this strong gender predisposition are poorly understood. Renal angiomyolipomas occur in 50–50% of sporadic LAM patients. The smooth muscle cells of pulmonary LAM and renal angiomyolipomas are nearly indistinguishable morphologically. Here, we report the first successful cell culture of a LAM-associated renal angiomyolipoma. The cells carded inactivating mutations in both alleles of the TSC2 gene and expressed estrogen receptor α, estrogen receptor β, and androgen receptor. To elucidate the cellular pathways through which steroid hormones influence LAM pathogenesis, we treated the cells with both estradiol and tamoxifen. Cell growth was stimulated by estradiol, associated with phosphorylation of p44/42 MAPK at 5 min and an increase in c-myc expression at 4 h. Tamoxifen citrate also stimulated cell growth, associated with increased phosphorylation of p44/42 MAPK and expression of c-myc, indicating that tamoxifen has agonist effects on angiomyolipoma cells. This response to tamoxifen in human angiomyolipoma cells differs from prior studies of Eker rat leiomyoma cells, possibly reflecting cell type or species differences in cells lacking tuberin. Our data provide the first evidence that estradiol stimulates the growth of angiomyolipoma cells, that tamoxifen has agonist effects in angiomyolipoma cells, and that estradiol and tamoxifen impact both genomic and nongenomic signaling pathways in angiomyolipoma cells. The responsiveness of angiomyolipoma cells to estradiol may be related to the underlying reasons that LAM affects primarily women. [ABSTRACT FROM AUTHOR]

TSC renal cystic disease is poorly understood and has no approved treatment. In a new principal cell-targeted murine model of Tsc cystic disease, the renal cystic epithelium is mostly composed of type A intercalated cells with an intact Tsc2 gene confirmed by sequencing, although these cells exhibit a Tsc -mutant disease phenotype. We used a newly derived targeted murine model in lineage tracing and extracellular vesicle (EV) characterization experiments and a cell culture model in EV characterization and cellular induction experiments to understand TSC cystogenesis. Using lineage tracing experiments, we found principal cells undergo clonal expansion but contribute very few cells to the cyst. We determined that cystic kidneys contain more interstitial EVs than noncystic kidneys, excrete fewer EVs in urine, and contain EVs in cyst fluid. Moreover, the loss of Tsc2 gene in EV-producing cells greatly changes the effect of EVs on renal tubular epithelium, such that the epithelium develops increased secretory and proliferative pathway activity. We demonstate that the mTORC1 pathway activity is independent form the EV production, and that the EV effects for a single cell line can vary significantly. TSC cystogenesis involves significant contribution from genetically intact cells conscripted to the mutant phenotype by mutant cell derived EVs., Competing Interests: The authors declare no conflict of interest., (© 2021 Chongqing Medical University. Production and hosting by Elsevier B.V.)

Tuberous sclerosis complex (TSC) is a neurocutaneous syndrome characterized by seizures, mental retardation, and benign tumors of many organs, including the brain, kidneys, skin, retina, and heart. TSC is caused by mutations in the TSC1 and TSC2 tumor suppressor genes. The genes follow the two-hit model for tumorigenesis, with germline mutations inactivating one allele and somatic mutations inactivating the remaining wild-type allele. Allelic loss (also called loss of heterozygosity [LOH]) in the 9q34 and 16p13 regions has been found in many tumor types from TSC patients. Cardiac rhabdomyomas are frequently found in infants with TSC. Because rhabdomyomas often spontaneously regress, access to fresh tissue is limited. In this chapter, we present methodology for detection of genetic inactivation of TSC1 and TSC2 in paraffin-embedded archival tissues. The template DNA is obtained either by direct scraping of tissue or after laser capture microdissection. LOH analysis is performed after polymerase chain reaction amplification of microsatellite markers in the 9q34 and 16p13 regions and denaturing polyacrylamide gel electrophoresis. Mutation detection is performed using single-strand conformation polymorphisms on mutation detection enhancement gels. Finally, variant bands are amplified and analyzed by direct sequencing.