Previously, we reported that unaggressive, growth factor-dependent FET human colon carcinoma cells downregulated their transforming growth factor alpha (TGFa) expression in a quiescent state (G 0 /G 1 ) induced by growth factor and nutrient deprivation (Mulder, 1991, Cancer Res.,
Expression of TGF-α/EGF and TGF-p receptors in human colon carcinoma cell lines
✍ Scribed by Uma Murthy; Mario A. Anzano; Russell G. Greig
- Publisher
- John Wiley and Sons
- Year
- 1989
- Tongue
- French
- Weight
- 957 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0020-7136
No coin nor oath required. For personal study only.
✦ Synopsis
Previous studies have established that colon carcinoma cells secrete several polypeptide growth factors, including TGF-dEGF and TGF-B, suggesting that these and related molecules function in an autocrindparacrine fashion to modulate tumor-cell growth. To investigate this possibility, we have studied the expression of transforming growth factor receptors in a panel of human colon carcinoma cell lines and in several untransformed epithelial cell populations. The results have revealed that neoplastic colon cells express receptors for both TGF-dEGF and TGF-fi. lmmunoprecipitation identified the TGF-dEGF receptor as a structurally intact 170-kDa protein. No evidence for over-expression was found. TGF-a (and EGF) enhanced receptor autophosphorylation, indicating that these receptors were biochemically functional. TGF-fi blocked DNA synthesis in non-neoplastic epithelial cells but not in tumorigenic colon populations. There was no correlation with TGF-fi receptor number or dissociation constant. However, chemical cross-linking studies revealed a TGF-fi receptor subtype of 75 kDa in 3 of the 4 colon carcinoma cells which was undetectable in normal IEC epithelial cultures, suggesting a possible association between 75-kDa receptor expression and refractoriness to growth inhibition of TGF-fi. Together, these data support the concept that locally-produced growth regulators can function in an autocrine or paracrine manner to influence the proliferation of colon carcinoma cells.
📜 SIMILAR VOLUMES
A number of studies suggest that an inverse correlation exists between the epidermal growth factor-receptor and the estrogen receptor expression in primary human breast carcinoma as well as in established human breast carcinoma cell lines. Recent studies suggest that the epidermal growth factor-rece
Studies on epidermal-growth-factor-like-, fibroblast- and transforming growth factors suggested their implication in tumorigenesis involving effects on tumour-cell proliferation and migration. In human transitional-cell carcinomas (TCC), enhanced expression of TGF alpha and EGF receptors correlated
## Abstract Spontaneously arising, TGFβ~1~‐resistant colonies were isolated directly from the soft agarose plates of MOSER human colon carcinoma cells grown in the presence of TGFβ~1~ but in the absence of serum. The colonies were cloned by limiting dilution and screened in a monolayer proliferatio
Autocrine transforming growth factor a (TGFa) activity and control mechanisms for its expression were examined in a representative clonal isolate (CBS4) of a well-differentiated human colon carcinoma cell line designated CBS. CBS4 cells expressed TGFa and its receptor, epidermal growth factor recept