John Leslie Collins

Tumor necrosis factor in peritoneal fluid of women undergoing laparoscopic surgery

The level of tumor necrosis factor (TNF) in peritoneal fluid (PF-TNF) of 74 women undergoing laparoscopy was determined. The difference between the mean concentration of PF-TNF of women with normal pelvic anatomy and women with moderate or severe endometriosis was significant (P less than 0.01). The proportion of PF-TNF-positive women with PID and those with moderate or severe endometriosis was also significantly higher when compared to women with normal pelvic anatomy (P less than 0.05; P less than 0.02). The proportion of PF-TNF positive women among nulligravid and nulliparous women was significantly higher than that of women with two or more pregnancies (P less than 0.01) and two or more deliveries (P less than 0.005). These results indicate that the presence of PF-TNF is associated with primary infertility and endometriosis.

The anticancer drug, cisplatin, increases the naturally occurring cell-mediated lysis of tumor cells

SummaryIt has been proposed that a component of the antitumor potential of the chemotherapeutic agent, cisplatin, resides in the hosts ability to respond to cisplatintreated tumor cells. Here we report that tumor cells that are normally resistant to lysis mediated by naturally occurring cytotoxic cells showed an increased sensitivity to lysis mediated by murine spleen cells or human peripheral blood monocytes and lymphocytes when cisplatin was added at the beginning of the lytic assay. This was shown for the lysis of both murine and human tumor cells. The pretreatment of tumor cells, but not effector cells with cisplatin caused an increase in lysis in the presence of murine spleen cells or human peripheral blood leukocytes, indicating that the effect of cisplatin is to reduce resistance to lysis by these effector cells. The lysis of tumor cells by naturally occurring cytotoxic cells was blocked by antibodies specific for tumor necrosis factor. In addition, the ability of cisplatin to increase lysis was seen with cells that are sensitive to natural cytotoxic cells, but not with cells that are sensitive to natural killer cells. These results suggest that the effector cells that mediate the lysis of these tumor cells in the presence of cisplatin are likely to be natural cytotoxic cells. The ability of cisplatin to increase the lysis of tumor cells by naturally occurring cytotoxic cells indicates that these cells may be a host defense mechanism that contributes to the anticancer potential of cisplatin.

Proliferative and antiproliferative effects of interferon-'Y and tumor necrosis factor-α. on cell lines derived from cervical and ovarian malignancies

Four human cell lines derived from cervical carcinomas (ME-180, SiHa, HT-3, and MS751) and three human cell lines derived from ovarian carcinomas (SK-OV-3, Caov-3, and NIH:OVCAR-3) were analyzed in vitro to determine the effect of recombinant interferon-gamma and recombinant human tumor necrosis factor-alpha on cell growth and survival. The effects of interferon-gamma, tumor necrosis factor-alpha, and both interferon-gamma and tumor necrosis factor-alpha on cell growth were measured after 24 and 72 hours of incubation by the incorporation of chromium 51. The results of this analysis showed that all seven cell lines were resistant to the antiproliferative action of tumor necrosis factor-alpha, that the growth of most cell lines was inhibited by interferon-gamma by 72 hours of incubation, and that after 72 hours of incubation all cell lines demonstrated a synergistic antiproliferative response to the combination of interferon-gamma and tumor necrosis factor-alpha. However, the effects of these cytokines on cell growth were found to differ among cell lines and varied with the concentration and the duration of incubation. The growth of one cell line (Caov-3) was stimulated by both tumor necrosis factor-alpha and interferon-gamma. These results suggest that the clinical effects of these cytokines on the growth of gynecologic cancers may be more complex than previously supposed.

In vitro analysis of the anticancer potential of tumor necrosis factor in combination with cisplatin

We have recently shown that cisplatin increases the natural cytotoxic (NC) cell-mediated lysis of a variety of human adenocarcinoma cell lines that are resistant to cisplatin or NC activity alone. Because NC lysis is mediated by tumor necrosis factor alpha (TNF) bound to the surface of NC effector cells, we analyzed the ability of TNF in combination with cisplatin to increase the lysis of tumor cells. The in vitro anticancer potential of the combination of TNF and cisplatin was determined for both dividing and nondividing populations of two human ovarian carcinoma cell lines, SK-OV-3 and OVCAR-3. Nondividing SK-OV-3 and OVCAR-3 cells are resistant to cisplatin and TNF when used as single agents. Dividing OVCAR-3 cells are approximately two times more sensitive to TNF than dividing SK-OV-3 cells, whereas dividing SK-OV-3 cells are approximately ten times more sensitive to cisplatin than dividing OVCAR-3 cells. TNF at 1000 units/ml in the presence of clinically low concentrations of cisplatin (0.6-0.25 micrograms/ml) increased the lysis of dividing OVCAR-3 cells above the value expected for the sum lysis mediated by cisplatin alone and lysis mediated by TNF alone. Similar results were obtained with dividing populations of the SK-OV-3 cell line. The combination of cisplatin and TNF did not increase the lysis of the nondividing populations of either cell line. The increased lysis of tumor cells combined with the maintenance of specificity for only dividing cells indicates that the combination of cisplatin and TNF may be useful for the treatment of tumors that are resistant to either cisplatin or TNF.

Divergent effects of taxol on tumor necrosis factor-α-mediated cytolysis of ovarian carcinoma cells

Abstract OBJECTIVE: Our objective was to study the combined effect of taxol and tumor necrosis factor-a on the cytolysis of human ovarian carcinoma cell lines, because taxol has been shown to be active against ovarian carcinoma and has also been shown to increase tumor necrosis factor-α release from macrophages. STUDY DESIGN: The combined effect of taxol and tumor necrosis factor-α on the cell lines Caov-3, SK-OV-3, NIH: OVCAR-3, and A2780, which are sensitive to the cytolytic effect of tumor necrosis factor-α in the presence of inhibitors of protein synthesis, was investigated with a 24-hour chromium 51 release assay. RESULTS: At therapeutic concentrations taxol caused a significant increase in tumor necrosis factor-α-mediated cytolysis of Caov-3 and A2780 ( p ≤ 0.05). By contrast, taxol caused a decrease in the tumor necrosis factor-α-mediated cytolysis of SK-OV-3 and NIH:OVCAR-3 ( p ≤ 0.01). CONCLUSION: These results suggest that ovarian carcinomas have a heterogeneous response to the chemotherapeutic effect of taxol. (AM J OBSTET GYNECOL 1992;167:1870-6.)

Enzyme immune assay determination of CA-125 in serum, peritoneal fluid, and follicular fluid from women with minimal endometriosis after ovarian hyperstimulation.

We conclude that the acutely preovulatory expression of CA-125 in serum and FF as determined by EIA is low and not significantly enhanced by OH. Although the PF concentrations were elevated in women with minimal endometriosis when compared with women without endometriosis, the still unresolved problem associated with measurements of CA-125 in PF for both RIA and EIA and the considerable overlap in individual values between both patient groups preclude its use as a reliable screening or monitoring parameter, at least for the present.

Common expression of a tumor necrosis factor resistance mechanism among gynecological malignancies.

SummaryThe efficacy of tumor necrosis factor α (TNFα) as an anticancer agent is limited. This limitation might be related to the expression of a protein-synthesis-dependent resistance mechanism that prevents the lysis of tumor cells by TNFα. To test this possibility eight randomly selected human cell lines, three derived from ovarian carcinomas and five derived from cervical carcinomas, were tested for their in vitro sensitivity to TNFα-mediated lysis. The results of this analysis showed that all eight cell lines are normally resistant to lysis by TNFα. However, in the presence of inhibitors of protein synthesis, seven of them showed a significant increase in TNFα-mediated lysis. Measurement of protein synthesis showed that there is a linear correlation between the level of inhibition of protein synthesis and the level of TNFα-mediated lysis. The fact that seven of eight randomly selected cell lines are resistant to TNFα because they express a protein-synthesis-dependent resistance mechanism suggests that this mechanism of resistance may be common among gynecological cancers. The results also suggest that a therapy involving TNFα and inhibitors of protein synthesis might be useful for the treatment of gynecological malignancies.

Dexamethasone used as an antiemetic in chemotherapy protocols inhibits natural cytotoxic (NC) cell activity

Because dexamethasone is often included as an antiemetic in chemotherapy protocols that involve cisplatin and because cisplatin has been shown to increase the in vitro lysis of tumor cells by natural cytotoxic (NC) effector cells, we determined the NC activity of 27 patients who received dexamethasone in conjunction with seven different cisplatin‐based chemotherapy protocols. The results of this analysis showed that the NC activity of patients who received cisplatin‐based chemotherapy protocols that included dexamethasone was reduced significantly 24 hours after treatment compared with before treatment (P < 0.001). The addition of dexamethasone (at a concentration equivalent to the plasma level of patients treated with dexamethasone) to the in vitro assay of NC activity caused a significant decrease in NC activity compared with when dexamethasone was not added (P < 0.001). There was no cumulative effect of dexamethasone in that the reduction of NC activity by dexamethasone was not significantly different in patients who had been treated previously at least four times and in patients who were treated for the first time. When dexamethasone was not included in the chemotherapy protocol the NC activity of 19 patients was not reduced 24 hours after treatment. These results indicate that dexamethasone causes a significant reduction in NC activity. Although the tumor surveillance role of human NC cells in vivo has not been established, the effect of dexamethasone on NC cells suggests that additional research of the effect of dexamethasone in cisplatin‐based chemotherapy protocols is warranted.

A Rapid In Vitro Screening System for the Identification and Evaluation of Anticancer Drugs

We report the development of an in vitro screening system that can be used to identify new anticancer drugs that are specifically cytotoxic for dividing cells. The screening system takes advantage of the potential of many cell lines, including tumor cells, to stop dividing when they are plated at high cell density. The cytotoxic effects of anticancer drugs on dividing (i.e., cells plated at low cell density) and nondividing cells (i.e., cells plated at high cell density) is measured by the incorporation of 51Cr. This in vitro system was evaluated by measuring the cytotoxic effects of the anticancer drugs cisplatin, thiotepa, doxorubicin, methotrexate, and vinblastine on the cell lines B/C-N, ME-180, and MCF-7. In this in vitro system the concentrations of the anticancer drugs that produced significant cytotoxicity on only dividing cells are similar to the concentrations that are used clinically. The fact that this in vitro system is rapid, simple, applicable to many cell types, and able to predict effective concentrations of anticancer drugs should make it useful for the screening of new anticancer drugs and for the design of preclinical studies.

Inhibition of protein synthesis enhances the lytic effects of tumor necrosis factor α and interferon γ in cell lines derived from gynecological malignancies

SummaryFew clinical responses have occurred in preliminary studies using the cytokines tumor necrosis factor α (TNFα) or interferon γ(IFNγ) in cancer patients. This may be related to the observation that many malignant cell lines are resistant to lysis by these cytokinesin vitro. Resistance to lysis by TNFα or IFNγ in many cells is controlled by a protein-synthesis-dependent mechanism, such that when protein synthesis is inhibited cells become sensitive to lysis by these cytokines. Because there is some evidence that TNFα and IFNγ act through different lytic mechanisms and are opposed by different resistance mechanisms, we treated a panel of eight cell lines, five derived from human cervical carcinomas (ME-180, MS751, SiHa, HT-3, and C-33A) and three derived from ovarian carcinomas (Caov-3, SK-OV-3, and NIH: OVCAR-3) with both TNFα and IFNγ to determine whether such combination treatment might maximizein vitro cell lysis. Our results showed that pretreatment with IFNγ followed by exposure to TNFα in the presence of protein synthesis inhibitors increased lysis of seven of the eight cell lines above that seen with either TNFα or IFNγ and inhibitors of protein synthesis. Only the cell line C-33A was resistant to lysis by TNFα and IFNγ, when exposed to these agents both alone and in combination with protein synthesis inhibitors. Clinically, combining the cytokines TNFα and IFNγ with protein synthesis inhibitors may maximize thein vivo lytic effects of these cytokines.