Heterogeneity of Human Breast Cancer Cell Clones with respect to Cytotoxic Susceptibility detected by Cytotoxic T-Lymphocytes and Natural Killer Cells

Clonal heterogeneity of human breast cancer cells, HMC-1, with respect to the cytotoxic susceptibility against autologous cytotoxic T-lymphocytes (CTL), TcHMC-1, and natural killer- (NK) cells was demonstrated in a ??Cr release cytotoxicity assay. We have established 8 tumor cell clones, HMC-1-1 through HMC-1-8, from HMC-1 cells and autologous TcHMC-1 clone that showed high cytotoxic activity as well. In the cytotoxicity assays, HMC-1-8 clone showed significantly high cytotoxic susceptibility by TcHMC-1, and conversely, HMC-1-7 clone showed low cytotoxic susceptibility. In case of autologous NK cells as effector, HMC-1-8 clone showed low cytotoxic susceptibility and HMC-1-7 clone did high. On the other hand, as to lymphokine-activated killer (LAK) cells, such heterogeneity as TcHMC-1 and NK cells demonstrated was not shown by either autologous or allogeneic LAK cells. These heterogeneous cytotoxic susceptibilities were further examined to determine whether they are related to the tumorigenicity of HMC-1 clones using a soft agar assay, showing that HMC-1-8 clone indicated significant high plating efficiency and HMC-1-7 showed low plating efficiency. The results of this study indicated that the heter-ogeneity of HMC-1 clones in cytotoxic susceptibility was shown by autologous CTL and NK cells but not by LAK cells, and the NK susceptibility alone seemed to be concerned with the tumorigenicity of tumor cells. To achieve moreeffective cancer immunotherapy, it is thought to be necessary to clarify such a new type of tumor heterogeneity in cytotoxic susceptibility

Characterization of p53 gene mutations in fine-needle aspirated breast cancer : correlation with clinicopathological features and short-term relapse

Mutations of the p53 gene play a key role in the development of common human malignancies. In the case of breast cancer patients, cancer cells can be obtained directly from the patient with minimal damage by fine-needle sampling. Thus, the method of aspiration biopsy cytology (ABC) by fine-needle aspiration biopsy (FNAB) was developed, enabling us to prepare cancer cell nuclei for detection of p53 gene mutation by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. Fine-needle samplings were successfully performed and p53 gene mutations were disclosed in 25 advanced breast cancer patients. We investigated 27 mutations of the p53 gene in these 25 specimens, showing all point mutations including 10 CpG mutations and 3 double mutations in one allele. Of the 25 patients with p53 gene mutations, 16 patients were disease free (64.0%) but 9 had postoperative recurrence (36.0%) ; in detail, 7 patients (28.0%) experienced short-term relapse of disease, i. e. recurrence within 5 years after operation. In the study using FNAB, we further examined the correlation of p53 gene mutation in breast cancer with clinicopathological features, and especially with short-term relapse of disease. No significant correlation was found with respect to age, menopausal status, histological type, ER status, operative procedures, and postoperative adjuvant therapy in almost all tumors, however there was a significant relationship between p53 gene mutation and short-term relapse (P<0.01). Moreover, p53 gene mutation related closely with nuclear p53 protein accumulation (P<0.01) and with DNA aneuploidy pattern as well (P<0.001). Twelve p53 gene mutations were shown in 9 aspirated biopsy specimens. All were point mutations containing 8 transitions, 2 transversions, and 2 deletions ; the dominant mutations were transition at GC base pairs (G to A), constituting 41.7% of all mutations. Typical hot spot codons in the study were codon 175, 248, and 282.Mutations localizing at the CpG site of the gene were seen in 7 cases (58.3%). Additionally, there was a tendency of high recurrence of disease in advanced clinical stage IIIA and IIIB, lymph node metastatic estimation of N2/N3, and histologic grade 3. These results thus indicate that p53 gene mutations in aspirated breast cancer cells obtained by FNAB reflect the biological characteristics of breast cancer and may be a good indicator of short-term relapse of postoperative patients