Correlation of DNA ploidy and S-phase fraction with chemotherapeutic response and survival in a randomized study of disseminated malignant melanoma

DNA ploidy and S-phase fraction analysis in peritoneal carcinomatosis from ovarian cancer: correlation with clinical pathological factors and response to chemotherapy

Objective

We investigated the correlation between ploidy or S-phase fraction (SPF) and the clinical pathological characteristics of patients with peritoneal carcinomatosis from ovarian cancer. We also assessed their relation with the in vivo and in vitro response to several chemotherapeutic agents.

Patients and methods

Fifty-three patients with peritoneal carcinomatosis from ovarian cancer were enrolled. Frozen tumor tissue was dissociated by a detergent–trypsin method, and the resulting cell suspension was stained with RNase A and propidium iodide. Samples were then analyzed for ploidy and SPF by flow cytometry. Fresh tumor tissue was dissociated by enzymatic digestion, and cells were exposed to different concentrations of cisplatin, adriamycin, carboplatin, gemcitabine and taxol for 72 hours. In vitro drug sensitivity was then measured using the sulforhodamine B assay.

Results

No significant correlation was found between ploidy or SPF and patient characteristics, even though primary carcinomas were mainly hyperdiploid and more proliferative than recurrent tumors. SPF differed significantly among ploidy categories (P=0.01), and high SPF was associated with short-term survival (P=0.48). Patients with multiploid tumors were the most resistant to platinum-based chemotherapy, whereas those with hyperdiploid tumors were the most responsive. In vitro multiploid tumors were the least sensitive, while hypodiploid samples showed the highest sensitivity to the tested drugs. Sensitivity to adriamycin was significantly correlated with ploidy (P=0.03), whereas sensitivity to taxol was correlated with SPF (P=0.04).

Conclusion

Our results indicate that ploidy and SPF could facilitate the choice of therapy for patients with peritoneal carcinomatosis.

Knocking-down cyclin A(2) by siRNA suppresses apoptosis and switches differentiation pathways in K562 cells upon administration with doxorubicin

Cyclin A₂ is critical for the initiation of DNA replication, transcription and cell cycle regulation. Cumulative evidences indicate that the deregulation of cyclin A₂ is tightly linked to the chromosomal instability, neoplastic transformation and tumor proliferation. Here we report that treatment of chronic myelogenous leukaemia K562 cells with doxorubicin results in an accumulation of cyclin A₂ and follows by induction of apoptotic cell death. To investigate the potential preclinical relevance, K562 cells were transiently transfected with the siRNA targeting cyclin A₂ by functionalized single wall carbon nanotubes. Knocking down the expression of cyclin A₂ in K562 cells suppressed doxorubicin-induced growth arrest and cell apoptosis. Upon administration with doxorubicin, K562 cells with reduced cyclin A₂ showed a significant decrease in erythroid differentiation, and a small fraction of cells were differentiated along megakaryocytic and monocyte-macrophage pathways. The results demonstrate the pro-apoptotic role of cyclin A₂ and suggest that cyclin A₂ is a key regulator of cell differentiation. To the best of our knowledge, this is the first report that knocking down expression of one gene switches differentiation pathways of human myeloid leukemia K562 cells.

A high proliferation rate measured by cyclin A predicts a favourable chemotherapy response in soft tissue sarcoma patients

A small but not insignificant number of patients experience a prolonged survival after treatment of metastatic soft tissue sarcoma. This must be weighed against the majority of the patients who benefit little from the therapy, but nevertheless experience its side-effects. It would therefore be of utmost importance to be able to screen for those patients who respond to the treatment. Since proliferating cells are more sensitive to chemotherapy than non-proliferative cells, we measured the proliferation rate of the primary tumour of 55 soft tissue sarcoma patients with locally advanced or metastatic disease by determining the flow cytometric S phase fraction and immunohistochemical Ki-67 and cyclin A scores. S phase fraction or Ki-67 score did not predict chemotherapy response or progression-free survival. A high cyclin A score, however, correlated with a better chemotherapy response (P = 0.02) and longer progression-free survival time (P = 0.04). Our results suggest that a high cyclin A score predicts chemotherapy sensitivity.

MIB-1 immunoreactivity correlates with blood vessel density and survival in disseminated malignant melanoma

The purpose of our current work was to evaluate the prognostic significance of tumor cell proliferation in advanced metastatic melanomas and to investigate a possible correlation between the proliferation index and blood vessel density in metastatic tissue. Sixty patients with disseminated malignant melanoma treated with four-drug chemotherapy combined with interferon-alpha were included in this study. Proliferative activity and vascularity in metastatic tissues were examined by immunohistochemistry with anti-Ki-67 (MIB-1) and anti-CD31 antibody, respectively. A significant relationship between MIB-1 index and blood vessel number was detected (rho = 0.323, p = 0.013). In survival analysis, the overall survival and disease-free survival were significantly longer (58 and 38 vs. 38 and 17 months) for patients with low MIB-1 immunoreactivity (p = 0.012 and p = 0.023, respectively). Likewise, the low MIB-1 labeling index was associated with the prolonged survival calculated from the initiation of the chemoimmunotherapy (12 vs. 7 months, p = 0.032). In multivariate Cox's proportional hazard analysis, MIB-1 positivity was an independent prognostic factor both for overall survival and for survival after beginning of the chemoimmunotherapy (p = 0.016 and p = 0.029).

Different prognostic effect of postoperative chemoradiation therapy on diploid and nondiploid high-risk rectal cancers

PURPOSE

DNA ploidy has been shown to play a role in the response to cytotoxic therapy in a variety of malignancies, including breast cancer and melanoma. However, the importance of DNA ploidy in rectal cancer is unknown. The aim of the present study was to determine whether ploidy status might be associated with response to postoperative chemoradiation in TNM Stages II to III rectal cancer.

METHODS

This retrospective study analyzed data from 229 patients with TNM Stages II to III rectal cancer who underwent resection between 1979 and 1984. The ploidy status and treatment modalities in relation to outcome were assessed.

RESULTS

The recurrence-free ten-year survival rate was 52.2 percent for patients with diploidy and 50.5 percent for patients with nondiploidy (P = 0.99). The ten-year survival rates for patients with diploidy and patients with nondiploidy were 55 and 19 percent (P = 0.016) in the chemoradiation group, and 51 and 60 percent (P = 0.15) in the nonchemoradiation group, respectively. In the chemoradiation group, DNA nondiploidy was associated with an increased recurrence rate (83.3 vs. 50.0 percent; P = 0.001). The interaction between DNA nondiploidy and chemoradiation remained important in predicting outcome in the Cox regression model. Factors independently correlated with a worse outcome included Stage IIIb (relative risk, 2.9; 95 percent confidence interval, 1.7-5; P = 0.0001), perineural invasion (relative risk, 2.5; 95 percent confidence interval, 1.6-4, P = 0.0001), distal tumor (relative risk, 1.7; 95 percent confidence interval, 1.1-2.7, P = 0.014), and nondiploidy with chemoradiation (relative risk, 2.9; 95 percent confidence interval, 1.2-7.2, P = 0.0213).

CONCLUSIONS

These findings suggest that DNA nondiploidy is inversely correlated with long-term outcome among patients with high-risk rectal cancer receiving chemoradiation.

Endoscopic diagnosis and treatment of early cancer in the alimentary tract

Due to the recent widespread use of detailed endoscopy together with careful scrutiny of the mucosa using dye-spraying techniques, there has been a general acceptance in Japan that early malignancies in the alimentary tract may not appear polypoid or ulcerative. Regardless of organ, superficial early cancers have been reported. These lesions appear as faint mucosal irregularities or discolorations, which may be difficult to distinguish from nonspecific inflammation or trauma. The recognition of these malignancies has prompted the development of new techniques for their treatment. Endoscopic mucosal resection (EMR) which can resect lesions as completely as specimens removed at open surgery, has become the first choice of treatment for early digestive cancer. The lesions that can be removed by EMR should be those which hardly ever carry lymph node metastases. Endoscopically, they are shown to be flat esophageal cancers, gastritis-like cancers and colorectal cancers less than 2 cm in flat elevated type or less than 1 cm in depressed type. In spite of the advances in characterizing early cancers and an emerging consensus on indications and contraindications for EMR, much work remains to be done. New techniques will continue to push the limits of what can be achieved via an endoscope.

Role of glutathione, glutathione S-transferases and multidrug resistance-related proteins in cisplatin sensitivity of head and neck cancer cell lines

Resistance to chemotherapy is a major problem in the treatment of patients with head and neck squamous cell carcinoma (HNSCC). Important factors involved are drug detoxification by glutathione (GSH) and reduced drug accumulation due to active transport out of the cell by so-called 'multidrug resistance-related proteins'. We have studied a panel of eight HNSCC cell lines showing differences in sensitivity to the anti-cancer drug cisplatin. Our previous studies indicated that the IC50 values were inversely correlated with the intracellular accumulation of platinum (Pt). In the present study, cellular GSH levels were found not to be related to the IC50 values. The expression levels of the enzymes glutathione S-transferase (GST) alpha, mu, and pi, the multidrug resistance-related proteins P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP) and the lung resistance protein (LRP) were determined semiquantitatively by means of immunocytochemistry. The levels of the GSTs, P-gp and LRP were not found to be correlated with the IC50 values of the HNSCC cell lines. Surprisingly, however, an inverse correlation was found between MRP levels and IC50 values. The MRP expression levels were in agreement with the results of the MRP functional assay, based on the transport of calcein across the cell membrane as performed for two of the cell lines. Further studies should prove whether other pump mechanisms or DNA repair are involved in the cisplatin accumulation and the subsequent HNSCC cell growth inhibition.

Systemic therapy of malignant melanoma

The present status of medical treatment of malignant melanoma is briefly reviewed, both with regard to adjuvant therapy for individuals with high-risk melanoma and a high probability of harbouring subclinical micrometastases, as well as to therapy for established disseminated (macrometastatic) disease. At present, disseminated, macrometastatic melanoma is incurable in the majority of cases. Single agent chemotherapy has modest effects and results in disease remission in a minority of patients, usually of short duration, Combination chemotherapy, or the combination of chemotherapeutic drugs and cytokines, results in increased response rates and occasionally remissions of prolonged duration. So far, no regimen has demonstrated improved survival compared to single agent therapy in disseminated melanoma. New insights into the mechanisms of resistance to chemotherapeutic drugs may lead to development of predictive tests that can identify individuals with tumors sensitive to a specific agent, as well as to the development of strategies to circumvent drug resistance. It has recently been shown that adjuvant therapy of high-risk melanoma with large doses of interferon-alpha 2b significantly prolongs relapse-free and overall survival, at the price of considerable toxicity. Ongoing studies aim to define the optimum dose and duration of adjuvant interferon therapy. Recent advances in molecular biology and immunology may lead to the development of new treatment modalities, such as improved vaccines and other biologic therapies, which may benefit patients with malignant melanoma.

Elevated serum levels of S100 and survival in metastatic malignant melanoma

Current reports suggest serum S100 as a prognostic marker for disease progression in advanced malignant melanoma. In this study, we assessed serum levels of S100 and multiple clinical factors in relation to overall survival in 99 patients with metastatic malignant melanoma seen at our institution between May 1990 and April 1996. For statistical analysis, we used both univariate and multivariate Cox proportional-hazards models. Elevated serum levels of S100 correlated with poor outcome in metastatic malignant melanoma (P < 0.0001), univariate analysis). Upon multivariate analysis, however, S100 added no information to known clinical prognostic parameters.

Expression of the multidrug resistance-associated protein (MRP) gene in urothelial carcinomas

The intrinsic or acquired resistance of urothelial cancer to chemotherapy is one major obstacle to successful treatment. Generally, the expression level of P-glycoprotein in urothelial cancer is low, so we accordingly investigated the expression of multidrug resistance-associated protein (MRP). We examined the expression of MRP mRNA by means of slot-blotting samples of 11 renal pelvic and/or ureteral tumors, 33 bladder tumors, one lung metastasis from a ureter tumor, 7 non-cancerous urothelia from patients with transitional-cell carcinoma (TCC) and one urothelium from a patient with renal-cell carcinoma (RCC). We also estimated, by Southern blotting, whether or not the MRP gene was amplified in clinical specimens that overexpressed MRP mRNA. MRP was detected immunohistochemically using a polyclonal antibody against MRP. In all, 5 of 11 renal pelvic and/or ureter tumors (45.5%), 17 of 33 bladder tumors (51.5%) and 4 of 7 non-cancerous urothelia of TCC patients (57.1%) expressed more than 2-fold the MRP mRNA levels of drug-sensitive human KB cells. There was no significant difference in the MRP mRNA level between primary and recurrent tumors. Low-grade urothelial carcinomas (G1 and G2 TCCs) expressed significantly higher levels of MRP mRNA than the high-grade G3 TCC. The MRP gene was not amplified in urothelial carcinomas, irrespective of their expression levels of MRP mRNA. Immunohistochemically, MRP was located mainly on the plasma membrane, but also detected on the cytoplasm of cancer cells. MRP may be one mechanism responsible for intrinsic drug resistance in low-grade urothelial cancer.

Anti-estrogens enhance the therapeutic effect of lymphokine-activated killer cells on the P815 murine mastocytoma

Tamoxifen (TX) and toremifene (TO) enhanced the lysis of P815 mastocytoma cells in vitro by syngeneic DBA2 spleen cells that have been activated by human recombinant interleukin-2 (IL-2) for 6 days (lymphokine-activated killer [LAK] cells). Similarly, enhanced tumor suppression occurred when TX- or TO-treated P815 cells were mixed with LAK cells and injected s.c. into normal DBA2 recipients. Tumor suppression could be increased further by treating such recipients orally with TX or TO and by the repeated injections of LAK cells into the tumor site. The treatment of animals bearing tumors (5 mm in diameter) orally with TX or TO or with LAK cells i.p. resulted in tumor suppression. When the drug treatment was combined with LAK cells, tumor suppression was more pronounced, and complete tumor regression was induced in a significant number of the animals so treated. Our results indicate that the immunotherapeutic effect of LAK cells can be significantly amplified by combined treatment with the anti-estrogens TX or TO.