The prognosis of colorectal cancer has been based essentially on pathological data for many years. The analysis of genetic anomalies has led to fundamental progress and clinical advances. Genetic anomalies are routinely studied. 1--Flowcytometry evaluates the quantity of DNA in the nucleus during the cell cycle. 2--Cytogentics is the study of karyotype anomalies by loss or gain of chromosome material and structural changes. 3--Molecular biology gives a means of recognizing chromosome losses and especially to study oncogenic or antioncogenic mutations. These analyses allow: 1--an evaluation of their value as a prognosis factor and thus their use for indicating adjuvant medical and/or surgical treatments. 2--an understanding of cancerogenic processes. 3--the development of future therapeutic techniques based on a better understanding of the mechanisms involved. 4--familial counselling in high risk families and an examination of responsible or favouring genes in certain familial cancers. Research into familial forms has recently led led to the demonstration of genetic alterations located on chromosomes 1 and 2. These anomalies called RER correspond to alterations found on tumors. Studying these alterations will allow better prediction of high risk subjects in cancer families without polyposis.

The spontaneous release of a glyconucleoprotein complex in the supernatant of eukaryote cell cultures is a general phenomenon independent of cell lysis. The DNA recovered from this glyconucleoprotein material contains most part of the genome. The SW 480 cell line, originating from a human colon carcinoma, presents a point mutation of the K-ras gene on both alleles. These cells in culture release the mutated K-ras gene. When crude SW 480 cell supernatant is given, without any other adjonction, to NIH/3T3 mouse cells, transformed foci appear as numerous as those occurring after a transfection provoked by a cloned E.J. ras gene administered as a calcium precipitate. The presence of a mutated ras gene in the transfected foci of the 3T3 cells has been checked by hybridization, after PCR, with an oligonucleotide probe specific to the mutation. This result was confirmed by sequencing the PCR product.

A phenotype of resistance to the new vinca alkaloid Navelbine was induced in the J82 human bladder carcinoma cells. The resistance factor of the resistant cell line (J82-NVB) to Navelbine was 17. The resistance phenotype of these cells is not a multidrug-resistance (MDR) phenotype. J82-NVB cells lack overexpression of P-glycoprotein and cross-resistance to MDR drugs like doxorubicin, epipodophyllotoxins or colchicine. Navelbine efflux was similar in sensitive and resistant cells, and resistance could not be explained by a difference of drug accumulation in these two cell lines. The cells were cross-resistant to vinca alkaloids and taxoids whose targets are microtubules. Immunofluorescence study of microtubules showed that depolymerization occured for the same Navelbine concentration in sensitive and resistant cells. This concentration induced growth inhibition in sensitive but not in resistant cells. Moreover, depolymerization induced by Navelbine treatment was reversible, after drug removal, in resistant cells only. This study suggests that J82-NVB cell resistance mechanism involves alterations of microtubule dynamics, allowing recovery of microtubules functions after treatment.

In view of the potent mitogenic effect exerted by insulin in human colonic cells, we used Caco-2 cells transfected with an activated (Val12) human Ha-ras gene or the polyoma middle T (PyMT) oncogene, a constitutive activator of pp60c-src tyrosine kinase activity, to investigate the effect of oncogenic p21ras and PyMT/pp60c-src on insulin mitogenic signaling. As compared to vector control Caco-2 cells, both oncogene-transfected cells exhibited: 1) a lost of response to insulin's stimulatory effect on mitogen-activated protein (MAP) kinase activity and cell proliferation, both of which were constitutively increased; 2) a decrease in insulin receptor (IR) affinity and insulin-stimulated exogenous tyrosine kinase activity, which resulted, at least in part, from increased protein kinase C (PKC) activity (4), since both IR alterations were partially corrected by PKC down-regulation; and 3) a decrease in both insulin receptor mRNA level and insulin receptor number, which was independent of PKC since it persisted after PKC down-regulation. In conclusion, oncogenic p21ras and PyMT/pp60c-src abolished insulin mitogenic signaling in Caco-2 cells through mechanisms involving (i) constitutive activation of MAP kinase, and (ii) marked decreases in both insulin receptor function and expression which were mediated by PKC-dependent and PKC-independent pathways respectively. This is the first evidence that, when oncogenically activated, p21ras and pp60c-src not only exert a negative control on insulin receptor function but also repress insulin receptor gene expression in human colonic cells.

Soft tissues sarcomas are an heterogeneous group of neoplasms. Their epidemiology is still poorly known. Great strides have been made in the genetic study over the last few years. Histologic grade, tumor size and deep location are the main independent prognostic factors in multivariate analysis using the Cox model. Overall 5-year survival is approximately 50% in most of the studies. Surgical conservative treatment associated with radiotherapy is actually preferred to radical surgery, because no survival difference is found between the two treatments. Radiation therapy modalities are discussed: preoperative, postoperative irradiation, interstitial brachytherapy. Doxorubicin, ifosfamide and DTIC are the most efficient drugs. However, response rates obtained with polychemotherapy are still less than 50%. High-dose chemotherapy is an encouraging concept. Edatrexate and Taxotere show interesting response rates in phase II clinical trials. Adjuvant chemotherapy efficiency is probably low: a meta-analysis shows a 5-year survival increase of 9%. Neoadjuvant chemotherapy allows a high rate of conservative treatment.

During their progression, epithelial tumors induce a stromal reaction essential for their development and for metastasis. In situ hybridization studies have revealed that the protooncogene c-ets1 is expressed in endothelial cells at the beginning tumor angiogenesis, and in stromal fibroblasts surrounding invasive tumors. C-ets1 encodes a transcription factor that may activate the transcription of genes encoding collagenase 1, stromelysin 1 and urokinase plasminogen activator, proteases involved in extracellular matrix degradation. A working hypothesis is that c-Ets1 takes part in regulating invasive processes by controlling the transcription of these genes. Experimental evidences that may confirm this hypothesis will be discussed.

Culture of human breast cancer cell lines has made it possible to better understand how oestrogens and anti-oestrogens interact with oestrogen receptors and thus regulate breast cancer cell growth. In addition, since human cell lines are cultured, immunologic and genetic probes can be used to compare in vitro cell behaviour with in vivo tumour development. The discovery of certain proteins, specifically induced by oestrogens and secreted in cell cultures, led us to the hypothesis that oestrogen might influence cell growth via a relay protein secreted by cancer cells. Results obtain in our laboratory over the last 15 years allowed us to define cathepsin D, an oestrogen-regulated protein now under study as a prognostic marker for metastasis. For patients, the implications of such fundamental results are great since clinicians could adapt management on the basis of a more specific prognosis. Nevertheless, it must be kept in mind that although in vitro cell cultures can provides an extremely fruitful model of cancer cell growth, in vivo breast cancer is not equivalent to a mono-layer of epithelial cancer cells growing in a Petri dish. Use of co-cultures and simplified in vivo models may be a new route to further developments. Progress, in terms of patient benefit, depends directly on rapid communications between research laboratories and clinical oncologists engaged in developing new tumour markers.

We have created transgenic mice lines in which SV40 T and c-myc expression was controlled by the L-pyruvate kinase gene regulatory region which is responsible for hepatic and pancreatic expression specificity, and strong dependence of this expression upon the carbohydrate composition of the diet. Models of hepatoma and endocrine pancreatic tumors have been obtained. Both tumors were dependent upon the diet, since carbohydrates strongly increased frequency and precocity of both hepatic and pancreatic carcinomas.

Amplification of c-myc and c-erb beta-2 (HER-2/neu) proto-oncogenes were analyzed in breast cancer tissues obtained from 100 patients without lymph node involvement (N-). An amplification of the c-myc gene was detected in four cases and a c-erb beta-2 (HER-2/neu) amplification in eight cases. The frequency of these abnormalities were compared to classical prognostic parameters as well as to new biological prognostic markers (cellular cycle, cathepsin-D and pS2 protein). Most of altered tumors were associated to some classical poor prognostic factors such as: steroid receptor-negative tumors, poorly differentiated tumors, high histoprognostic grade and tumor cell density. In contrast, no relation was found with new biological parameters. The analyses of these data in relation to clinical evolution will be of interest to evaluate their prognostic value.

Does the c-ets 1 protooncogene take part in the regulation of tumor angiogenesis? The formation of new blood vessels is an essential process in embryonic development and wound healing, for tumor growth and metastasis. In situ hybridization studies have revealed that the protooncogene c-ets 1 is expressed in endothelial cells at the beginning of blood vessel formation, in normal and pathological conditions. C-ets 1 encodes a transcription factor, a protein which binds specifically to DNA and which regulates the transcription of genes containing these specific binding sequences in their promotors. Thus in vitro experiments suggest that c-ets 1 may activate the transcription of genes encoding collagenase 1, stromelysine 1 and urokinase plasminogen activator, proteases involved in extracellular matrix degradation. A working hypothesis is that c-ets 1 takes part in regulating angiogenesis by controlling the transcription of these genes whose activity is necessary for the migration of endothelial cells from preexisting capillaries. This hypothesis is discussed with respect to current experimental evidences and to the complexity of the regulatory network controlling gene transcription and extracellular matrix degradation.

The flow-cytometry (FCM) is a method of quickly determining the desoxyribonucleic acid (DNA) content of tumoral cells. This provides us with two results: the DNA-ploidy which characterizes quantitatively the DNA, and the percentage of cells in DNA synthesis phase (%S). The contribution of FCM in evaluation of the prognosis of non-small cell lung cancer remains disputable. The absence of standardization between laboratories makes it difficult to compare the different studies to define the place of FCM analysis. However, for epidermoid carcinomas, the most actively studied, a DNA diploidy and a weak %S have a favourable impact on survival. No conclusion can be drawn from the studies on adenocarcinomas. Large cell carcinomas have never been studied in an isolated manner, due to the lack of numbers.

mdm2 (mouse double minute) protein seems lead to p53 inactivation and therefore might potentially play a role in carcinogenesis. We have studied mdm2 gene amplification from 239 primary breast cancer tissues. mdm2 gene was amplified in 10% of cases (25/239). mdm2 amplification was associated with c-erbB2 amplification (P < 10(-3)). No other correlation was found. However there was inverse correlation between c-erbB2 gene amplification and hormonal receptors (P < 10(-4)), only from patients without mdm2 gene amplification.

The relationship between constitutional chromosome aberrations and a predisposition to malignancy has already been established.

Progress in detecting genetic anomalies with proven prognostic value in colorectal cancers offers a means of selecting adjuvant therapy with the best probability of success. Several methods are currently used. With flow cytometry, a significant correlation between primary tumour ploidy and hepatic metastasis has been demonstrated. Caryotypes of tumour cells provides a means of exposing segmental or total chromosome loss and subsequent classification leads to a better understanding of tumour heterogeneity. New techniques in molecular biology are used to describe mutations. Monoclonal antibodies can then be developed against the epitopes involved. Based on these different methods clinicians and fundamentalists can analyse treatment results with more precision and thus adopt the most effective treatment protocol.

PCR can be used at different levels in oncology as many examples illustrate. Interchromosomal translocations that can be detected by PCR are very specifically found i.e. in follicular lymphomas. In the context of follow-up controls this may reduce recurrencies. By the identification of genetic lesions of an oncogene, aggressivity of a tumor may be estimated. PCR allows rapid analysis of such lesions. Analysing deletions of tumor suppressor-genes gains increasing importance in oncology. By amplification of microsatellites, presence of such a deletion may be detected. This analysis is not only important for studies of sporadic tumors but may also indicate in individual cases if the patient carries a predisposition for a certain tumor.

The goal of indirect molecular diagnostic techniques is the detection of a link between a specific allele of a polymorphic genomic marker and a given disease. This technique is used in two specific clinical situations: 1) when the gene is unknown and the search for a mutation or a gene product is impossible 2) when the gene is known but large and several mutations might be present. If none of the known mutations prevails in the local population the systematic and sequential search for every single mutation is not economical. A linkage study is required in those instances. The indirect analysis was up to the nineties based on markers detecting DNA-restriction fragments of various length. By the amplification of microsatellites by PCR the indirect approach has brought enormous progress. Together with the mapping by the Human Genome Project it will progress further. Although indirect molecular methodology can often avoid extended work it is only applicable to families with a member already affected by the disease. DNA from this individual is needed for the detection of a link of one allele to the disease. This means necessarily that the disease must be inherited and that the diagnosis is certain. Presymptomatic molecular diagnosis is illustrated by the analysis of a pedigree with familial adenomatous polyposis by microsatellite PCR techniques.

Acute promyelocytic leukemia is a rare disease combining a specific cell type, a bleeding diathesis and a translocation t(15;17). All trans retinoic acid is able to induce a maturation of malignant cells, up to terminal differentiation. After 2 months of treatment a complete remission is obtained without any aplastic anemia. The bleeding diathesis rapidly disappears. However relapses occur within few months due to the catabolism of retinoic acid induced by the treatment itself. A chemotherapy is generally proposed, in order to consolidate the complete remission. The combination of retinoic acid and chemotherapy has dramatically increased the probability of long term survival. The breakpoint of the translocation t(15;17) is located inside the retinoic acid receptor gene on chromosome 17. A new product is made, due to the fusion of the truncated retinoic acid receptor and a gene on chromosome 15. The hybrid product blocks the program normally performed by the retinoic acid receptor and consequently blocks the maturation of the granulocytes. Why pharmacological doses restore the impaired program is still an enigma.