The ChemoFx assay: an ex vivo cell culture assay for predicting anticancer drug responses.

We provide a detailed description of the ChemoFx Assay, a phenotype-based cell culture assay for predicting anticancer drug responses in individual cancer patients. The ChemoFx Assay is based on the outgrowth and short-term primary culture of epithelial cells derived from pieces of solid tumor adenocarcinomas that are obtained at the time of tumor resection. Malignant epithelial cells are grown attached in wells of microtiter plates and treated with six escalating doses of chemotherapeutic drug. Using an operator-controlled automated image analysis system, cell kill is measured microscopically by counting the number of live cells remaining after dead cells have detached and are subsequently rinsed away. A dose-response graph is automatically generated by comparing the number of cells in drug-treated wells with those in control wells.

Metastatic lung disease to the central nervous system: in vitro response to chemotherapeutic agents.

BACKGROUND: Metastatic lung disease to the central nervous system (CNS) comprises a significant percentage of cranial metastases. For those cases where chemotherapy may be of palliative or therapeutic benefit, in vitro chemoresponse testing may identify the agent(s) most likely to be effective clinically. METHODS: Tumor-derived cell cultures were established from 14 surgically excised lung lesions metastatic to the CNS. In vitro chemoresponse testing was performed with a variety of anticancer agents on the tumor cells that grew out of the cultured tissue specimens. Drug concentrations and exposure times were adjusted to bracket approximate average peak plasma levels that are observed typically in vivo. For each tumor-derived cell culture, a complete dose-response curve was established for each chemotherapeutic agent tested. RESULTS: Approximately 80% of the 14 tumor cell cultures had a definitive response to one or more chemotherapeutic agents in vitro, with approximately one-third of these cultures displaying a response to at least three of the drugs tested. There was considerable heterogeneity in the response of individual tumor cell cultures to the chemotherapeutic drugs. The agents that showed the highest cytotoxic response rate against the individual tumor cell cultures included lomustine, carboplatin, cisplatin and etoposide. CONCLUSIONS: The tumor cells isolated from individuals with lung lesions metastatic to the brain demonstrated differential chemoresponses to the agents tested. No single agent was effective against every tumor cell culture. These data suggest that in vitro chemoresponse testing of cultured tumor cells may be useful to identify biologically effective chemotherapeutic agents for individual patients, thereby addressing at least one factor in this complex therapeutic challenge.

Breast cancer--response rates to chemotherapeutic agents studied in vitro.

BACKGROUND: The biological efficacy of, and spectrum of action of, agents used in treatment of breast cancer are important issues in therapy planning. MATERIALS AND METHODS: Techniques used involve monolayer culture and a quantitative microtiter plate-based chemo-response assay. Precision Therapeutics' overall assessability rate is 90% for tumors of all types. In this study, 148 specimens derived from breast cancer were studied. Of these, 111 were additionally studied histopathologically. Ninety-two percent of the 111 specimens were confirmed to be epithelioid in nature and, thus, compatible with cells of breast cancer origin. RESULTS: In vitro chemo-response profiles indicated that individual agents stratified into groups, with cyclophosphamide and fluorouracil demonstrating responses of 69% and 57% respectively; doxorubicin, 45%; and docetaxel, paclitaxel and gemcitabine, 39, 27 and 36%, respectively. CONCLUSION: The spectrum of responsiveness of the individual agents was variable and not completely overlapping, as shown by the Venn diagrams.

Evidence for the isolation, growth, and characterization of malignant cells in primary cultures of human tumors.

Isolation and growth of malignant cells from solid tumors have often met with disappointing results. Consequently, we have developed a cell culture methodology based on ex vivo explantation of tumor tissue, with subsequent monolayer cell outgrowth. In an attempt to assess methods for detection of malignant cells in these cultures, we analyzed and compared the results of cytopathology, growth in soft agar, and detection of telomerase activity with those of standard immunohistochemistry (IHC) techniques for the detection of cytokeratins, tumor marker p53, and proliferation marker Ki-67. The sensitivity of detection of malignant cells was 85% (22/26) for cytopathological examination, 30% (3/10) for soft agar growth, and 100% (12/12) for detection of telomerase activity. From these data, we concluded that both cytopathological examination and assessment of telomerase activity contribute to the detection of malignant cells in primary cultures of human solid tumors, whereas growth in soft agar was not a good indicator of malignant cells. Although not specific for malignant cells per se, IHC detection for epithelial cell cytokeratins showed a high degree of sensitivity (100%, 23/23), whereas the sensitivity for detection of tumor marker p53 and proliferation marker Ki-67 was 30% (7/23) and 70% (16/23), respectively. These data also provide proof that malignant tumor cells, derived from a diverse number of human solid tumors, can be isolated and grown in primary cell culture.

In vitro responses of ovarian cancers to platinums and taxanes.

We describe the in vitro patterns of response of explanted primary and recurrent ovarian cancers to platinum- and taxane-based chemotherapeutics. The chemoresponse assay utilizes cells that grow out from tumor fragments and are then challenged with varied concentrations of chemotherapeutic agents, coupled with a highly quantitative cell counting analysis system. The in vitro response rates for 268 primary cancer explants were 24% and 54% for carboplatin and cisplatin, respectively, and 31% and 25% for docetaxel and paclitaxel, respectively. Recurrent tumors presented lower rates of responsiveness, as expected. Furthermore, the chemotherapies worked on overlapping but distinct populations, even within the same class of drug, with 14% of the carboplatin-sensitive tumors being cisplatin-resistant and 59% of the cisplatin-sensitive tumors being carboplatin-resistant. These in vitro responses compare favorably to published in vivo clinical response rates. The current study serves to demonstrate how an in vitro predictive assay can be used as a surrogate for clinical therapeutic challenge.