For the past 30 years strategies for the preclinical discovery and development of potential anticancer agents have been based largely upon the testing of agents in mice bearing transplantable leukemias and solid tumors derived from a limited number of murine as well as human sources. The feasibility of implementing an alternate approach, namely combined in vitro/in vivo screening for selective cytotoxicity among panels of human tumor cell lines derived from a broad spectrum of human solid tumors is under investigation. A group of 30 cell lines acquired from a variety of sources and representing 8 lung cancer pathologies as well as 76 cell lines representing 10 other categories of human cancer (carcinomas of colon, breast, kidney, prostate, ovary, head and neck; glioma; leukemia; melanoma; and sarcoma) have exhibited acceptable growth characteristics and suitable colorimetric profiles in a single, standard culture medium. Measurements of in vitro growth in microculture wells by cell-mediated reduction of tetrazolium showed excellent correlation (0.89 less than r2 less than 0.98) with measurements of cellular protein in adherent cell line cultures as well as viable cell count in suspension cell line cultures (0.94 less than r2 less than 0.99). Since the microculture tetrazolium assay provides sensitive and reproducible indices of growth as well as drug sensitivity in individual cell lines over the course of multiple passages and several months' cultivation, it appears suitable for initial-stage in vitro drug screening.

https://cancerres.aacrjournals.org/content/canres/48/3/589.full.pdf

Feasibility of Drug Screening with Panels of Human Tumor Cell Lines Using a Microculture Tetrazolium Assay

The LNCaP cell line was established from a metastatic lesion of human prostatic adenocarcinoma. The LNCaP cells grow readily in vitro (up to 8 x 10(5) cells/sq cm; doubling time, 60 hr), form clones in semisolid media, are highly resistant to human fibroblast interferon, and show an aneuploid (modal number, 76 to 91) human male karyotype with several marker chromosomes. The malignant properties of LNCaP cells are maintained. Athymic nude mice develop tumors at the injection site (volume-doubling time, 86 hr). Functional differentiation is preserved; both cultures and tumor produce acid phosphatase. High-affinity specific androgen receptors are present in the cytosol and nuclear fractions of cells in culture and in tumors. Estrogen receptors are demonstrable in the cytosol. The model is hormonally responsive. In vitro, 5 alpha-dihydrotestosterone modulates cell growth and stimulates acid phosphatase production. In vivo, the frequency of tumor development and the mean time of tumor appearance are significantly different for either sex. Male mice develop tumors earlier and at a greater frequency than do females. Hormonal manipulations show that, regardless of sex, the frequency of tumor development correlates with serum androgen levels. The rate of the tumor growth, however, is independent of the gender of hormonal status of the host.

https://cancerres.aacrjournals.org/content/canres/43/4/1809.full.pdf

LNCaP model of human prostatic carcinoma.

Quantitative proteome profiling using stable isotope protein tagging and automated tandem mass spectrometry (MS/MS) is an emerging technology with great potential for the functional analysis of biological systems and for the detection of clinical diagnostic or prognostic marker proteins. Owing to the enormous complexity of proteomes, their comprehensive analysis is an as-yet-unresolved technical challenge. However, biologically or clinically important information can be obtained if specific, information-rich protein classes, or sub-proteomes, are isolated and analyzed. Glycosylation is the most common post-translational modification. Here we describe a method for the selective isolation, identification and quantification of peptides that contain N-linked carbohydrates. It is based on the conjugation of glycoproteins to a solid support using hydrazide chemistry, stable isotope labeling of glycopeptides and the specific release of formerly N-linked glycosylated peptides via peptide- N-glycosidase F (PNGase F). The recovered peptides are then identified and quantified by MS/MS. We applied the approach to the analysis of plasma membrane proteins and proteins contained in human blood serum.

Identification and quantification of N-linked glycoproteins using hydrazide chemistry, stable isotope labeling and mass spectrometry

Prostate specific antigen: a critical assessment of the most useful tumor marker for adenocarcinoma of the prostate.

During the past 10 years, preclinical studies implicating sustained androgen receptor (AR) signalling as the primary driver of castration-resistant prostate cancer (CRPC) have led to the development of novel agents targeting the AR pathway that are now in widespread clinical use. These drugs prolong the survival of patients with late-stage prostate cancer but are not curative. In this Review, we highlight emerging mechanisms of acquired resistance to these contemporary therapies, which fall into the three broad categories of restored AR signalling, AR bypass signalling and complete AR independence. This diverse range of resistance mechanisms presents new challenges for long-term disease control, which may be addressable through early use of combination therapies guided by recent insights from genomic landscape studies of CRPC.

/pdf/emerging-mechanisms-of-resistance-to-androgen-receptor-4ky3dotyrw.pdf

Emerging Mechanisms of Resistance to Androgen Receptor Inhibitors in Prostate Cancer

The LNCaP cell line - A new model for studies on human prostatic carcinoma

Specificity of a previously reported prostate antigen (PA) was assessed by several immunologic procedures. This antigen, restricted in distribution to the prostate gland, was detected within ductal epithelial cells. Continuous established cell lines LNCaP and PC-3 of malignant prostate origin retained the expression of PA. Tumor cells released the antigen in vitro into the culture fluid and also in vivo into the circulation of nude mice preinoculated with LNCaP cells. Prostate cells in culture also specifically accreted immunoglobulin fragments of PA antiserum.

S S Leong

Papers

The LNCaP cell line - A new model for studies on human prostatic carcinoma

Prostate Antigen: A Marker for Human Prostate Epithelial Cells

Human prostate epithelial cell-specific antigen.