Michael B. Sporn

Bio: Michael B. Sporn is an academic researcher from Dartmouth College. The author has contributed to research in topics: Transforming growth factor & Transforming growth factor beta. The author has an hindex of 157, co-authored 559 publications receiving 94605 citations. Previous affiliations of Michael B. Sporn include Cornell University & Reata Pharmaceuticals.

Retinyl Acetate: Effect on Cellular Content of RNA in Epidermis in Cell Culture in Chemically Defined Medium

Abstract: Cell cultures of epidermis from newborn mice were established in chemically defined medium. Additions of retinyl acetate to these cultures caused a significant increase in cellular RNA content. Addition of insulin and hydrocortisone to the cultures potentiated the effect of retinyl acetate on cellular RNA content.

Roles for transforming growth factors-β in the genesis, prevention, and treatment of breast cancer

Abstract: Cell proliferation is normally controlled by the opposing actions of growth stimulators and growth inhibitors. Regulated changes in this balanced system determine the rate of tissue growth during embryogenesis, and later in response to damage or altered functional demand. The negative autocrine hypothesis proposed that any defect in a normal autocrine growth-inhibitory loop could lead to tumor formation in the affected cell type by upsetting this balance [1]. The mechanistic underpinning of this hypothesis lies in the fact that cellular proliferation is a prerequisite for the fixation of deleterious mutations, and thus for tumor promotion and malignant progression [2]. Evidence for the importance of loss of negative regulation in tumorigenesis has been provided by the identification and characterization of ‘tumor suppressor’ genes, exemplified by the retinoblastoma gene, where loss of both alleles leads with high frequency to the development of a particular malignancy [3].

Inhibition of Urinary Bladder Cancer by N-(Ethyl)-all-trans-retinamide and N-(2-Hydroxyethyl)-all-trans-retinamide in Rats and Mice

Abstract: The chemopreventive activity of two synthetic retinamides of relatively low toxicity against N-butyl-N-(4-hydroxybutyl)nitrosamine (OH-BBN)-induced urinary bladder cancer was studied in F344 rats and C57BL/6 X DBA/2 F1 mice. Female and male rats were given a total dose of either 1800 or 3200 mg OH-BBN over a period of 6 or 8 weeks, respectively. Male mice were given a total dose of either 90 or 180 mg OH-BBN over a period of 9 weeks. Seven days after the final intubation of a period of 9 weeks. Seven days after the final intubation of OH-BBN, animals were fed either a placebo diet or a diet supplemented with the following retinoids: for rats, 0.8 mmol 13-cis-retinoic acid, 2 mmol N-(ethyl)-all-trans-retinamide, or 2 mmol N-(2-hydroxyethyl)-all-trans-retinamide per kg diet; and for mice, either 0.5 or 1.0 mmol of N-(ethyl)-all-trans-retinamide or N-(2-hydroxyethyl)-all-trans-retinamide per kg diet. Animals were killed 6 months after the initial gastric intubation. In comparison to male and female rats fed placebo diets, all three retinoids reduced the incidence, number, and severity of the low-grade papillary transitional cell carcinomas of the urinary bladder. Similarly, treatment of mice with either of the two retinamides reduced the incidence of highly invasive urinary bladder carcinomas. The chemopreventive effect of the less toxic retinamides was equal to or greater than that of 13-cis-retinoic acid.

Transforming growth factor alpha: an aromatic side chain at position 38 is essential for biological activity.

Abstract: Site-directed mutagenesis has been performed in the human transforming growth factor alpha gene. When tyrosine 38 is mutated into phenylalanine or tryptophane, biological activity is retained. In contrast, other alterations between cysteine 34 and cysteine 43 and disruption of disulfide bonds 8 to 21 and 34 to 43 resulted in loss of activities. The presence of an aromatic side chain at position 38 of transforming growth factor alpha seems to be essential for its activity.

Tricyclic-bis-enone derivatives and methods of use thereof

Abstract: Novel tricyclic-bis-enone derivatives (TBEs) as well as the process for the preparation of such TBEs are provided. Also provided are methods for prevention and/or treatment of cancer, Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotropic lateral sclerosis, rheumatoid arthritis, inflammatory bowel disease, and all other diseases whose pathogenesis is believed to involve excessive production of either nitric oxide (NO) or prostaglandins or the overexpression of iNOS or COX-2 genes or gene products. Further, methods for the synthesis of the TBE compounds of the invention utilize cheap commercially available reagents and are highly cost effective and amenable to scale-up. Additional high efficiency synthetic methods that utilize novel intermediates as well as the synthesis of these intermediates are also provided. Furthermore, the invention also provides methods for designing novel and water-soluble TBEs.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

The pathogenesis of atherosclerosis: a perspective for the 1990s

Abstract: Atherosclerosis, the principal cause of heart attack, stroke and gangrene of the extremities, is responsible for 50% of all mortality in the USA, Europe and Japan. The lesions result from an excessive, inflammatory-fibroproliferative response to various forms of insult to the endothelium and smooth muscle of the artery wall. A large number of growth factors, cytokines and vasoregulatory molecules participate in this process. Our ability to control the expression of genes encoding these molecules and to target specific cell types provides opportunities to develop new diagnostic and therapeutic agents to induce the regression of the lesions and, possibly, to prevent their formation.

TGF-beta signal transduction.

Abstract: The transforming growth factor beta (TGF-beta) family of growth factors control the development and homeostasis of most tissues in metazoan organisms. Work over the past few years has led to the elucidation of a TGF-beta signal transduction network. This network involves receptor serine/threonine kinases at the cell surface and their substrates, the SMAD proteins, which move into the nucleus, where they activate target gene transcription in association with DNA-binding partners. Distinct repertoires of receptors, SMAD proteins, and DNA-binding partners seemingly underlie, in a cell-specific manner, the multifunctional nature of TGF-beta and related factors. Mutations in these pathways are the cause of various forms of human cancer and developmental disorders.