Direct "wet" staining of tumour or haematopoietic colonies in agar culture

Human melanoma cells derived from lymphatic metastases use integrin alpha v beta 3 to adhere to lymph node vitronectin

Human melanoma is a highly metastatic cancer and the regional lymph nodes are generally the first site of metastasis. Adhesion to cryostat sections of human lymph nodes was therefore studied using two human melanoma models established from lymph node metastases, namely, MeWo cell lines of diverse metastatic potentials and a highly metastatic cell line of recent origin designated MIM/8. We found a good correlation between the metastatic potentials of the melanoma cells as measured in nude mice and their ability to adhere to cryostat sections of human lymph nodes. When adhesion to immobilized extracellular matrix proteins was measured, a significant increase in adhesion, which correlated with increased metastasis, was seen mainly on vitronectin and to a lesser extent on fibronectin. The adhesion to vitronectin and to the frozen sections were specifically blocked by an RGD-containing peptide, mAb 661 to vitronectin and mAb LM609 to integrin alpha v beta 3. FACS analysis revealed a significant and specific increase in cell surface expression of alpha v beta 3 on the metastatic cells as compared to the parent line. Together these results suggest that the adhesion of melanoma cells to lymph node vitronectin via the alpha v beta 3 receptor plays a role in the process of lymphatic dissemination.

Ovarian carcinoma cells in culture: assessment of drug sensitivity by clonogenic assay

Ovarian tumours were cultured by clonogenic assay and drug sensitivity profiles obtained for cis-platinum, adriamycin and phosphoramide mustard. Results were correlated with clinical outcome. Two hundred samples were received from 106 patients and 115/167 with malignant cytology (69%) were cultured successfully. Drug results were obtained on 71 samples and in untreated patients 60% of samples (48% of patients) were markedly sensitive to cis-platinum and 87% of samples (76% of patients) were sensitive to adriamycin. Eighty-one percent of cases sensitive to adriamycin were also sensitive to cis-platinum. Two of 7 samples were sensitive to phosphoramide mustard; the remainder were resistant. Eighty percent of samples from treated patients were resistant in vitro to drugs already received. Seventy-one samples from 57 patients were suitable for drug study. Forty-eight patients received chemotherapy, but only 23 received the drugs tested. Clinical correlations showed that in vitro sensitivity to cis-platinum and adriamycin was related to a good clinical response. No correlations were observed between cis-platinum and adriamycin resistance in vitro and clinical outcome. Unexpected relationships, however, were observed between cis-platinum resistance and failure to respond to other alkylating agents received singly. No such relationship has been demonstrated for adriamycin.

[Predictive tumor tests in chemotherapeutic treatment concepts of malignant diseases]

In order to determine the pre-therapeutical effectiveness of cytotoxic drugs in metastasizing tumours, two in vitro test methods were examined for their predictive validity: the short-term incubation of tumour cells with cytotoxic drugs and radioactive labelled precursors of the DNA- or RNA-synthesis, and the testing of the cloning ability of tumour cells, pre-incubated with cytotoxic drugs. The short-term incubation techniques were directed in two directions: the testing of sensitivity and the testing of resistance. Both methods can only be carried out using strong proliferating tumours. With methodical, pharmalogical and biological problems, the sensitivity test results in a relatively minor correlation between the in vitro and in vivo reactions. Contrary to this the resistance test allows a predictive, clinically utilizable judgement of primary and secondary forms of the tumour-cell resistance of specific cytotoxic drugs. The consecutive measurement of the proliferative activity of tumours before and after a systematic chemotherapy also seems to be an able parameter concerning the clinically expected effectiveness of cytotoxic drugs. Compared to the other in vitro tests the tumour-cell clonogenic assay demonstrates two main advantages: firstly, all cytotoxic drugs can be analysed by this test method, and secondly, little proliferating tumours can also examined. Nevertheless, this test method seems to be more suitable for predicting tumour-cell resistance than the sensitivity of cytotoxic drugs.

Human tumour karyology: marked analytic improvement by short-term agar culture

A simple method has been developed which facilitates the detailed cytogenetic analysis of proliferating tumour cells within clusters and colonies arising from clonogenic tumour stem cells in biopsy samples of human cancers. The method uses a simple agar cloning technique for human tumours, which provides marked enhancement in the number of cases with observable mitotic activity and the number of mitotic figures available for detailed karyotypic assessment. The frequency of mitotic figures in cluster and colony samples is much greater than is attainable with standard chromosomal techniques. This novel approach should prove to be a powerful tool for the study of human tumour karyology.