Sensitivity of fresh and cultured ovarian tumor cells to tumor necrosis factor, interferon-alpha 2, and OK-432

DNA profiling analysis of endometrial and ovarian cell lines reveals misidentification, redundancy and contamination

OBJECTIVES

Cell lines derived from human ovarian and endometrial cancers, and their immortalized non-malignant counterparts, are critical tools to investigate and characterize molecular mechanisms underlying gynecologic tumorigenesis, and facilitate development of novel therapeutics. To determine the extent of misidentification, contamination and redundancy, with evident consequences for the validity of research based upon these models, we undertook a systematic analysis and cataloging of endometrial and ovarian cell lines.

METHODS

Profiling of cell lines by analysis of DNA microsatellite short tandem repeats (STR), p53 nucleotide polymorphisms and microsatellite instability was performed.

RESULTS

Fifty-one ovarian cancer lines were profiled with ten found to be redundant and five (A2008, OV2008, C13, SK-OV-4 and SK-OV-6) identified as cervical cancer cells. Ten endometrial cell lines were analyzed, with RL-92, HEC-1A, HEC-1B, HEC-50, KLE, and AN3CA all exhibiting unique, uncontaminated STR profiles. Multiple variants of Ishikawa and ECC-1 endometrial cancer cell lines were genotyped and analyzed by sequencing of mutations in the p53 gene. The profile of ECC-1 cells did not match the EnCa-101 tumor, from which it was reportedly derived, and all ECC-1 isolates were genotyped as Ishikawa cells, MCF-7 breast cancer cells, or a combination thereof. Two normal, immortalized endometrial epithelial cell lines, HES cells and the hTERT-EEC line, were identified as HeLa cervical carcinoma and MCF-7 breast cancer cells, respectively.

CONCLUSIONS

Results demonstrate significant misidentification, duplication, and loss of integrity of endometrial and ovarian cancer cell lines. Authentication by STR DNA profiling is a simple and economical method to verify and validate studies undertaken with these models.

Appraisal of transarterial immunoembolization for hepatocellular carcinoma: a clinicopathologic study

Recurrence of hepatocellular carcinoma (HCC) is frequent, even after apparently curative resection. Preoperative transcatheter arterial chemoembolization (TAE) does not improve disease-free survival after hepatic resection. We previously reported the potential usefulness of transarterial immunoembolization (TIE), a newly developed arterial embolization technique using OK-432 and fibrinogen, as preoperative treatment. In this study, we further investigated the effect of TIE by histologic examination of the resected specimens and compared it with conventional TAE in a prospective nonrandomized manner. Thirty-nine patients underwent TIE (n = 17) or TAE (n = 22) before curative hepatectomy for HCC. Transarterial immunoembolization was performed according to the standard protocol using OK-432, fibrinogen, and thrombin. Histologic changes in cancerous and noncancerous liver tissues were examined at different stages after TIE. Histologic grading of cancer cell injury according to the modified Shimosato criteria (Grades 0-IV, in increasing order of severity of cell injury) and postoperative disease-free survival were compared between the two groups. Based on the results of histopathology, TAE was more effective than TIE against the main tumor. In contrast, TIE was significantly more effective than TAE against extracapsular invasion and intrahepatic metastasis. Disease-free survival after hepatectomy tended to be better in patients pretreated with TIE than TAE. Postoperative tumor recurrences in the TIE group (n = 4) occurred in the nontreatment regions, whereas tumor recurrences in TAE group developed mostly (8 of 11 patients) in treated liver regions. Based on results of histologic examination, TIE seems to be more effective than conventional TAE against extracapsular invasion and intrahepatic metastasis. Data for disease-free survival and recurrence site suggest TIE may be a useful preoperative treatment.

Potential advantages in therapeutic index of OK-432 ointment to abdominal skin over systemic applied in a mouse model

A mixture of OK-432 powder and an ointment base, lanolin, was applied to mouse abdominal skin. After application of the mixture of 5 KE OK-432 and 0.2g lanolin, the leucocyte count and IL-b content in the abdominal cavity increases to up to 3.6 x 10(6) cells and 1.4 ng, respectively. INF-gamma content in the cavity after application of a mixture of 10 KE OK-432 and 0.2 g lanolin also increases, although not after application of the 5 KE OH-432 mixture of dorsum subcutaneous injection of a saline solution of 5 KE OK-432. These results indicate that an application of OK-432 mixed in lanolin to the mouse abdomen is able to exert an influence on the immunomodulatory effect in the abdominal cavity. The concentrations of IL-6 in serum after applying the ointment mixture, and subcutaneous of intraperitoneal injection of the saline solution of 5 KE OK-432, were <20, 370, and 430 pg/ml, respectively. After application of the ointment mixture of 5 KE OK-432, serum IL-6 did not increase. IL-6 levels in the abdominal cavity after 5 KE OK-432 ointment of subcutaneous injection increases to up to 1.4 and 2.1 ng/cavity. From these results, the immunomodulatory systemic response of OK-432 brought about by applying OK-432 ointment to the abdominal skin is lower than that brought about by injecting OK-432 subcutaneously. Therefore, it is thought that application of OK-432 ointment might be most suitable for potentiating local immune response.

Anticancer chemosensitivity profile of freshly separated human pancreatic cancer cells assessed by DNA synthesis inhibition assay

The chemosensitivity of 49 freshly separated human pancreatic cancers to seven kinds of anticancer agents were assessed by a DNA synthesis (3H-thymidine incorporation) inhibition assay. DNA synthesis is higher in involved lymph nodes (n = 7), malignant effusion (n = 15), liver metastasis (n = 7), primary cancer (n = 15), and skin metastasis (n = 5). Chemosensitivity assay demonstrates that etoposide, 4-epirubicin, carboquone, and 5-fluorouracil are more effective than cisplatin, mitomycin-C, and Adriamycin. In general, metastatic lesions of pancreatic cancer tend to show higher chemosensitivity than primary lesions. Pathological analysis demonstrates that small primary pancreatic cancers tend to be more responsive than large primary cancers, and primary pancreatic cancers with no regional lymph node involvement also tend to be more responsive than those with nodal involvement. No significant differences are seen in terms of tumor spread, vascular involvement, sex of patient, and histological type. When chemosensitivity assay is not available, the results of the present study may be beneficial to choose the regimens.

Local injection of OK-432/fibrinogen gel into head and neck carcinomas

Immunotherapy with biological response modifiers (BRM) is a possible strategy against head and neck solid tumours. However, the rapid disappearance of BRM from the tumour area is one of the reasons for its limited clinical application. In this pilot study, fibrinogen gel containing OK-432 (a compound composed of attenuated Streptococcus pyogenes), an inducer of natural killer cells and T-cell cytotoxity, was injected directly into head and neck solid tumours of 15 patients. A dose of 5 Klinische Einheiten (KE) of OK-432 was reconstituted in 1 ml aprotinin and mixed with fibrinogen, the latter to maintain the OK-432 locally. 3 patients showed tumour regression, and in addition, we observed histological changes in the injected tumour of all patients. These results suggest that OK-432/fibrinogen gel generates a local immune response, leading to tumour regression.

A comprehensive multi-institutional study on postoperative adjuvant immunotherapy with oral streptococcal preparation OK-432 for patients after gastric cancer surgery. Kyoto Research Group for Digestive Organ Surgery

The current study was designed to compare the effects of oral administration of the streptococcal preparation, OK-432, as an adjuvant immunotherapy versus those of intradermal administration of OK-432 on the survival of patients after surgery for gastric cancer. The patients were stratified into two groups after surgery: a curative surgery stratum and a palliative surgery stratum. Then the patients in each stratum were randomly assigned into three groups: an oral placebo group, an oral OK-432 group, and an intradermal OK-432 group. All of the patients were given fluoropyrimidines orally in combination with OK-432 or placebo for 2 years after surgery. A total of 1011 patients were registered between 1982 and 1985, and 970 patients were eligible for statistical analysis. The survival rate of the oral OK-432 group was significantly higher than those of the other two groups after curative surgery. There were no significant difference in the survival rates between the three groups after palliative surgery, however. The effect of oral OK-432 was quite pronounced in patients after curative surgery for stage II to IV gastric cancer, especially in those patients with regional node involvement. Furthermore, it was found that the spleen is necessary for effective immunotherapy with oral OK-432, because the survival rate of the oral OK-432 group was significantly improved in patients whose spleens were preserved, when compared with splenectomized patients. These results demonstrate that oral adjuvant immunotherapy with OK-432 is beneficial after curative surgery for gastric cancer.

The streptococcal preparation OK-432 specifically augments the susceptibility of human urinary bladder tumor cells to autologous peripheral blood lymphocytes

The streptococcal preparation OK-432 was tested for its ability to enhance the susceptibility of fresh urinary bladder tumor (UBT) cells to autologous peripheral blood lymphocytes (PBL) in patients with UBT. PBL treated with OK-432 at 0.1 Klinishe Einheit (KE)/ml for 18 hours killed the human T24-lined UBT cells and freshly separated autologous UBT cells more efficiently than untreated PBL. Treatment of K562 erythroleukemia cells with OK-432 at 0.1 KE/ml for 18 hours had no effect on their susceptibility to lysis by fresh PBL. In contrast, treatment of T24 and fresh autologous UBT cells with OK-432 resulted in an enhancement of their susceptibility to PBL. The susceptibility of autologous UBT cells to both large granular lymphocytes (LGL) and T-lymphocytes was also enhanced by treatment of tumor cells with OK-432. Binding of PBL to T24 and fresh autologous UBT cells was also augmented by treatment of the tumor cells with OK-432. The frequency of binding of OK-432 to fresh UBT cells was positively correlated with the increased target sensitivity to autologous PBL. The inhibition of RNA synthesis in fresh UBT cells by OK-432 was also associated with the elevated susceptibility to autologous PBL. These results indicate that OK-432 activates the autologous tumor killing system through stimulation of effector cells and elevation of target susceptibility to effector cells in patients with UBT, and suggest that the OK-432-augmented target sensitivity to PBL may be oriented specifically to UBT cells and local immunotherapy with OK-432 may be remarkably beneficial in the treatment of UBT.

Immunotherapy of ovarian cancer. II. In vitro generation and characterization of lymphokine-activated killer T cells from the peripheral blood of recurrent ovarian cancer patients

We examined the in vitro sensitivity of continuous ovarian cancer cells to lymphokine-activated killer T cells (T-LAK) alone or in combination with cytokines. Lymphocyte viability in T-LAK cultures generated from normal donors and ovarian cancer patients declined in the first 2 to 4 days; however, the remaining cells in these cultures maintained a constant rate of proliferation for long periods in vitro. These cells became 90-95% CD3+ TCR+ -alpha/beta T-cells after 7-10 days in culture. The T-LAK cells from normal donors and cancer patients expressed an equal ability to induce lysis of a panel of human target cells (NK-sensitive K562, NK-insensitive RAJI, and two human ovarian tumor lines, SKOV-3 and OVCAR-3), demonstrating that they are nongenetically restricted killers. Preincubation of either the effector or target cells with tumor necrosis factor or interferon-gamma or addition of these cytokines directly to cytolytic assays did not alter the degree of cell lysis in vitro. This is a method for generating large numbers of autologous, cytolytically active T-LAK cells from the blood of ovarian cancer patients that could be employed in adoptive intraperitoneal immunotherapy.

Use of fibrinogen to enhance the antitumor effect of OK-432. A new approach to immunotherapy for colorectal carcinoma

OK-432 (5 KE), an immunomodulatory agent prepared from an attenuated strain of Streptococcus pyogenes, was dissolved in 1 ml of aprotinin (1000 KIE) and mixed with 80 mg of fibrinogen containing Factor XIII. A single intratumoral injection of the mixture was performed preoperatively under endoscopy in 20 patients with colorectal carcinoma. Postoperative histopathologic examinations revealed the formation of fibrin fibers at the site of injection and marked infiltration of inflammatory cells into the tumor stroma on the day after injection; the formation of granulomas containing many giant cells after 4 to 7 days; and extensive regression of tumor tissue after 14 days. This study suggests that the high concentration of exogenous fibrinogen gelatinized enough to trap OK-432 in tumor stroma and that OK-432 induced granulomatous hypersensitivity to degenerate tumor stroma, thereby causing regression of the tumors.

Chemosensitivity correlation between the primary tumors and simultaneous metastatic lymph nodes of patients evaluated by DNA synthesis inhibition assay

The chemosensitivities of primary tumors (PT) and simultaneous metastatic lymph nodes (MN) to mitomycin C (MMC), 5-fluorouracil (5-FU), Adriamycin (ADR) (doxorubicin; Adria Laboratories, Columbus, OH), carboquone (CQ), or cisplatin (CDDP) were assessed in a group of 29 patients (11 gastric, 8 colorectal, 4 breast, and 6 other cancers) by a DNA synthesis (3H-thymidine incorporation) inhibition assay. PT and MN from the same patient showed heterogeneity in chemosensitivity. MN were more sensitive to the agents than PT. PT were sensitive to 5-FU, whereas MN were sensitive to CDDP. An analysis of the sensitivity correlations showed that the sensitivities of PT to MMC, 5-FU, CQ, and CDDP correlated with each other, but ADR sensitivity correlated with only CQ sensitivity. The sensitivities of MN correlated with each other, except for those to ADR and CDDP. In contrast, MMC, ADR, or CQ sensitivity showed a correlation between PT and MN. These results suggest that patients should be treated according to the sensitivity of the target lesion. However, if the sensitivity assay is not available, the sensitivity correlation may be useful when choosing the agent. It also may be important that ADR sensitivity does not correlate with the sensitivities of other agents.

Activation of human peripheral blood-derived monocytes by OK-432 (Streptococcus pyogenes): augmented cytotoxicity and secretion of TNF and synergy with rIFN-gamma

The biological response modifier OK-432 has been shown both to exert the enhancement of several immunological activities and to have a direct anti-tumor effect. The present study examines the immunopotentiating effect of OK-432 on peripheral blood monocytes (PBM) derived from normal humans. Monocyte activation was assessed by examining direct cell-mediated cytotoxic activity (CMC) and secretion of cytotoxic factors in the supernatant by the 51Cr release assay and secretion of tumor necrosis factor (TNF)-alpha detected by a sensitive radioimmunoassay. The OK-432-augmented activity was compared to that achieved by recombinant interferon-gamma (rIFN-gamma). Coculture of PBM with OK-432 overnight resulted in significant augmentation of CMC and secretion of cytotoxic factors and TNF in the supernatant. The effects observed were dose dependent and the resulting activity was much more pronounced than that achieved with an optimal concentration of IFN-gamma. The monocyte- and supernatant-mediated cytotoxic activities were in a large part attributed to TNF as both activities were inhibited by anti-TNF antibody. Several parameters of monocyte activation by OK-432 were examined. The kinetics of monocyte activation revealed that a short time exposure (2-6 hr) was sufficient for activation but maximal activation was detected after 18 hr. However, the kinetics of the cytotoxic assay were not shortened and 16-20 hr was necessary for optimal cytotoxic activity. Significant synergy was obtained when suboptimal concentrations of OK-432 and IFN-gamma were used. The synergy was noted in CMC, supernatant activity, and TNF concentration. These results demonstrate that OK-432 is a potent activator of monocyte cytotoxicity and also activates secretion of TNF. Also, OK-432 is a much more potent activator than rIFN-gamma. The synergy with OK-432 and IFN-gamma suggests that OK-432-mediated activation of monocytes takes place by a different mechanism than that mediated by rIFN-gamma. Thus, monocytes and products thereof may actively participate in the in vivo anti-tumor effect mediated by OK-432.

Cytotoxic and cytostatic effects of the streptococcal preparation OK-432 and its subcellular fractions on human ovarian tumor cells

Previous studies have indicated that OK-432 is a potent biologic response modifier (BRM) and that it augments immune responses to tumor cells. We studied the direct effect of OK-432 on tumor cells. Established and freshly derived human ovarian carcinoma lines were examined for their susceptibility to OK-432 or its subcellular fractions in direct cytotoxicity, cytostatic activity, and inhibition of metabolic activity. OK-432 was cytotoxic to 13 of 15 freshly derived ovarian carcinoma lines in a 24-hour chromium-51 (51Cr) release assay. The optimal effect was noticed at OK-432 concentrations between 0.1 and 1.0 Klinishe Einhert (KE) per milliliter. The cytostatic effect on two established lines and one fresh line correlated with the cytotoxic activity. In all three lines, however, the metabolic activities (DNA, RNA, and protein synthesis) were inhibited by OK-432, suggesting that cell lysis by OK-432 may not be directly correlated with the inhibition of metabolic activities. Several subcellular fractions were derived from OK-432 and only the cytoplasmic and protoplast membrane fractions showed cytotoxic activity against the OK-432-sensitive tumor cell lines, although the cytotoxicity obtained was greatly less than the whole microorganism OK-432. The direct binding of 14C-OK-432 to tumor cells was examined. Binding took place rapidly after 1 hour of incubation and reached a maximum activity at 37 degrees C. Binding in all three lines ranged between 1.7 and 2.7 pg/cell. These results demonstrate the direct cytotoxic effect of OK-432 and some subcellular fractions on human ovarian carcinoma lines. These results also show that the BRM OK-432 may exert its effect by both potentiating the antitumor response and directly inhibiting tumor cell growth.