LA-12 overcomes confluence-dependent resistance of HT-29 colon cancer cells to Pt (II) compounds.

BACKGROUND: LA-12 is a new platinum (IV) drug with promising cytotoxic effects in a wide range of cancer cell lines. Its confluence-dependent effects were compared with cisplatin (CDDP) and oxaliplatin (L-OHP) in HT-29 cells. MATERIALS AND METHODS: Cytotoxicity was determined by MTT test, eosin exclusion assay, and cell number quantification. The cell cycle was analysed using propidium iodide DNA staining (flow cytometry), apoptosis by phosphatidylserine externalisation (annexin-V assay), mitochondrial membrane potential by flow cytometry, nuclear morphology by means of fluorescence microscopy, and PARP cleavage by Western blotting. RESULTS: While L-OHP and CDDP were practically inactive in the subconfluent cell population, LA-12 showed a similar toxicity in both subconfluent and growing populations. All compounds induced apoptosis, although with different potentials. CONCLUSION: LA-12 was able to overcome confluence-dependent resistance of HT-29 cells observed for other platinum compounds, which may have potential therapeutic use in slowly growing tumours.

Predicting non-sentinel lymph node status after positive sentinel biopsy in breast cancer: what model performs the best in a Czech population?

Several models have previously been proposed to predict the probability of non-sentinel lymph node (NSLN) metastases after a positive sentinel lymph node (SLN) biopsy in breast cancer. The aim of this study was to assess the accuracy of two previously published nomograms (MSKCC, Stanford) and to develop an alternative model with the best predictive accuracy in a Czech population. In the basic population of 330 SLN-positive patients from the Czech Republic, the accuracy of the MSKCC and the Stanford nomograms was tested by the area under the receiver operating characteristics curve (AUC). A new model (MOU nomogram) was proposed according to the results of multivariate analysis of relevant clinicopathologic variables. The new model was validated in an independent test population from Hungary (383 patients). In the basic population, six of 27 patients with isolated tumor cells (ITC) in the SLN harbored additional NSLN metastases. The AUCs of the MSKCC and Stanford nomograms were 0.68 and 0.66, respectively; for the MOU nomogram it reached 0.76. In the test population, the AUC of the MOU nomogram was similar to that of the basic population (0.74). The presence of only ITC in SLN does not preclude further nodal involvement. Additional variables are beneficial when considering the probability of NSLN metastases. In the basic population, the previously published nomograms (MSKCC and Stanford) showed only limited accuracy. The developed MOU nomogram proved more suitable for the basic population, such as for another independent population from a mid-European country.