Establishment and culture optimization of a new type of pituitary immortalized cell line

An improved method of culturing somatotropic cells from rat adenohypophysis

This study aimed to propose a simple and practical method for culturing primary rat somatotropic cells in vitro free of pericytes contamination. Rat adenohypophyses were randomly divided into two groups. An improved method was used in group A (digesting adenohypophysis with 0.25% trypsin-EDTA, followed by removing pericytes by double filtration and using serum-free medium for culturing somatotropic cells). The traditional method was used in group B (digesting adenohypophysis with 0.35% collagenase, using serum medium for culturing somatotropic cells, and removing pericytes by changing the culture dish). The numbers and viability of somatotropic cells were higher in group A than in group B after 6 days. GH secretion of somatotropic cells was also higher in group A than in group B. Besides, the pericytes grew rapidly only in group B after 3 days. α-SMA, type I collagen, and type III collagen had weaker expression in group A. Also, the viability of pericytes decreased in group A. The improved method could solve the problem of pericytes contamination, and the culture of primary rat somatotropic cells in vitro was successful. This method can be used for other primary cultures with pericytes contamination.

Establishment and characterization of a carcinoma-associated fibroblast cell line derived from a human salivary gland adenoid cystic carcinoma

Salivary gland adenoid cystic carcinoma (SACC) is one of the most common malignancies in the oral and maxillofacial region. Carcinoma-associated fibroblast (CAF) is an important component in the tumor microenvironment and participates in SACC progression. In this study, we established a CAF cell line derived from a human SACC and named it CAF-SA. It was identified that CAF-SA expressed typical CAF biomarkers. Then, we studied the cellular communications between CAF-SA, tumor cells and endothelial cells. It was found that CAF-SA promoted the migration, invasion, and proliferation of SACC tumor cells in vitro. In addition, tube formation by endothelial cells was enhanced by CAF-SA. In vivo experiment showed that SACC cells formed larger xenografts in nude mice when they were transplanted with CAF-SA. Overall, we demonstrated that CAF-SA exhibited the most important defining feature of CAF by promoting cancer progression.

Establishment of a protocol to extend the lifespan of human hormone-secreting pituitary adenoma cells

PURPOSE

The aim of this study was to generate immortalized human anterior pituitary adenoma cells. Reliable cell models for the study of human pituitary adenomas are as yet lacking and studies performed so far used repeated passaging of freshly excised adenomas, with the attendant limitations due to limited survival in culture, early senescence, and poor reproducibility.

METHODS & RESULTS

We devised a technique based upon repeated co-transfections of two retroviral vectors, one carrying the catalytic subunit of human telomerase, hTERT, the other SV40 large T antigen. This approach extended the lifespan of cells derived from a human growth hormone-secreting adenoma up to 18 months while retaining morphology of primary cells, growth hormone synthesis and growth hormone secretion.

CONCLUSIONS

Our attempt represents the first demonstration of successful lifespan extension of human growth hormone-secreting pituitary adenoma cells via co-transfection of hTERT and SV40T and paves the way to future attempts to obtain stable cell lines.

Immortalization of Porcine 11β-Hydroxysteroid Dehydrogenase Type 1-Transgenic Liver Cells Using SV40 Large T Antigen

Cortisol is a steroid hormone essential to the maintenance of homeostasis that is released in response to stress and low blood glucose concentration. Cortisol is converted from cortisone by 11β-hydroxysteroid dehydrogenase type 1 (HSD11B1). It has been reported that too much cortisol or overexpression of HSD11B1 induces obesity and the insulin resistance that accompanies metabolic syndrome in rodent adipose tissue. In our previous study, HSD11B1-transgenic (TG) fibroblasts were established, and a porcine model was generated by SCNT using those fibroblasts. Hepatocytes overexpressing HSD11B1 were obtained from livers of this porcine model and cultured in vitro. However, the primary hepatocytes were found to have a short life span or low proliferation rate. To overcome these problems, the SV40 large T antigen was transduced into primary HSD11B1-TG hepatocytes, and those cells were immortalized. Immortalized HSD11B1-TG hepatocytes showed restored morphology, more rapid proliferation rate, and more expression of HSD11B1 than primary hepatocytes. As well, these cells kept the hepatic characteristics such as gluconeogenic response to cortisone and increased expression of hepatic makers. The immortalized HSD11B1-TG hepatocytes may be useful for studying traits and potential therapeutic drugs for treatment of metabolic disorders induced by overexpression of HSD11B1.

Bovine lactotroph cultures for the study of prolactin synthesis functions

The aim of this study was to establish a bovine anterior pituitary-derived lactotroph (BAPDL) line that expresses prolactin (PRL) in vitro to study the mechanisms of bovine PRL synthesis and secretion. Immunohistochemistry assay of PRL in the newborn calves' anterior pituitary glands showed that most lactotrophs were located within the superior border of the lateral wings of the anterior pituitary. Tissues of the superior border of the lateral wings of the anterior pituitary were dispersed and cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS). The limiting dilution method was used to establish BAPDL from single cell clone. BAPDL cells constantly expressed mRNAs for PRL and pituitary-specific transcription factor 1 (Pit-1) gene and grew steadily and rapidly in the DMEM supplemented with 10% FBS. PRL immunoreactivity was present in BAPDL at passage 20. The concentration of bovine PRL in BAPDL at passage 20 culture supernatant was decreased to below 35% compared with that in BAPDL at passage 1. The effects of human epidermal growth factor (hEGF) and dopamine (DA) on the expression and secretion of PRL in BAPDL at passage 4 were also investigated. The results are consistent with those of previous studies. Thus, it can be used successfully for studying the mechanisms of stimuli regulating PRL synthesis and release.