EGF receptor and effects of EGF on growth and tumor marker secretion in uterine cervical cancer cells

Effects of EGF on proliferation and tumor marker secretion of cervical cancer cells are reported together with the characteristics of EGF receptors on the cells. TA-4 producing cell line (OMC-1) originating from cervical squamous cell carcinoma and CA-125 producing cell line (OMC-4) originating from cervical adenocarcinoma, were used. Scatchard plot of EGF binding to OMC-1 indicated a single class of binding sites with a dissociation constant (Kd) of 360pM, whereas that of OMC-4 was curvilinear suggesting two classes of binding sites with a Kd of 170pM and 510pM. The theoretical maximum number of binding sites of OMC-1 and OMC-4 was 2.4 X 10(4) and 1.6 X 10(5), respectively. Effects of EGF on growth were studied by monitoring cell number and the incorporation of 3H-thymidine into the DNA of the cells. OMC-1 was stimulated by EGF at low concentrations (0.01-0.1nM) and inhibited at higher concentrations. OMC-4 was not stimulated by EGF. The TA-4 secretion of OMC-1 was slightly stimulated by EGF at low concentrations (0.01-1nM) and significantly stimulated at high concentration (10nM). The CA-125 secretion of OMC-4 was not stimulated by EGF. These results suggest that there are some differences between cervical squamous cell carcinoma and adenocarcinoma in the mechanisms of regulation of proliferation and tumor marker secretion by EGF.     

In vitro studies on the expression of c-myc oncogene product in gynecological cultured cancer cells

In this study, immunocytochemical and biochemical detection of c-myc protein in gynecological cultured cancer cells were performed together with gene expression of the cells. OMC-1 (cervical squamous carcinoma cell line), OMC-2 (endometrial adenocarcinoma cell line), OMC-3 (ovarian mucinous adenocarcinoma cell line) and OMC-4 (cervical adenocarcinoma cell line) were used. Immunocytochemically, c-myc protein was detected in both nuclei and cytoplasms of cultured cells when they were fixed in 95% ethanol, 10% formalin and 4% paraformaldehyde (PFA) including 10mM NaCl. However, it was detected in the nuclei of almost all of the cells in nuclei of the cells when they were fixed in 4% PFA including 1,000mM NaCl. Western blotting against a nuclear fraction of the cells demonstrated 66Kd protein in OMC-1 and 62Kd protein in OMC-2,3,4, respectively. They were completely absorbed by c-myc synthetic peptide. However, there was no reaction against the cytoplasmic fraction of the cells. Slot blot hybridization against the DNA of the cells demonstrated 15 times and 5 times c-myc gene amplification in OMC-2 and OMC-4, respectively. These results suggest that OMC-1,2,3,4 can be used as positive controls for the immunocyto- and histochemical detection of c-myc protein in clinical materials. However, it must be noted that the redistribution of c-myc nuclear protein into the cytoplasm may occur in the fixation process.     

低浓度化学药物配合淋巴因子激活的杀伤细胞对人卵巢癌细胞体外 …

探讨低浓度化学药物配合淋巴因子激活的杀伤细胞能否增强对卵巢癌细胞的体外杀伤敏感性。方法应用１．５μｇ／ｍｌ泰素４μｇ／ｍｌ顺铂、２５μ／ｍｌ氟尿嘧啶,与人卵巢癌细胞系ＳＫＯＶ３作用１８小时后,采用＾５１Ｃｒ释放法,观察ＳＫＯＶ３对被白细胞介素２激活的ＬＡＫ细胞的杀伤敏感性;     

Studies on oral-adjuvant chemotherapy of uterine cervical cancer after surgical treatment

To improve the postoperative survival rate of patients with cervical cancer, those with clinical stage Ib or above were treated with adjuvant chemotherapy (oral Tegafur). The drug sensitivity of cultured cervical epidermoid cancer cells was tested with 5-fluorouracil (5-FU), an active derivative of Tegafur. The cumulative rate of recurrence of the group treated with adjuvant chemotherapy was 28.4% (19/67 cases), significantly lower than that of the untreated control group 69.8% (44/63 cases) (p less than 0.01). The rate of recurrence for the two groups was evaluated with Cox's regression models. The rate of recurrence of the treated group was about 50% that of the untreated group. The drug sensitivity of the cultured cancer cells was investigated with a colony forming assay, and a dose-response curve was obtained for the time-dependent anticancer drug. The inhibition of DNA synthesis peaked after 24 to 72 hours of incubation with 5-FU at 0.1 to 0.5 micrograms/ml, but the peak appeared in 4 to 8 hours at 1.0 to 10.0 micrograms/ml. Morphologic changes occurred after 192 hours of incubation at 0.1 microgram/ml. Investigation of the drug sensitivity by cell kinetics disclosed prolongation of the cell cycle after 144 hours at 0.1 microgram/ml and inhibition of cell cycle progression after 48 hours at 10.0 micrograms/ml. Thus, adjuvant chemotherapy with Tegafur reduces the rate of recurrence to about 50% in postoperative patients with cervical cancer. This finding was also supported by an experimental study.     

Establishment and characterization of TA-4 producing cell line (OMC-1) originating from a human squamous cell carcinoma of the uterine cervix

A new human cell line designated OMC-1 was established from a metastatic lesion of Virchow lymph node of a large cell non-keratinizing squamous cell carcinoma of the uterine cervix. OMC-1 was successively subcultured 30 times in about 15 months. The monolayer cultured cells appeared to be epithelial with a pavement-like arrangement and tendency to pile up without contact inhibition. Electronmicroscopy showed desmosomes and well-developed tonofilaments. The population doubling time was 43-70 hours, the saturation density was 1.3-1.7 X 10(5) cells/cm2, the plating efficiency was 23-25% and the mitotic index was 3.3-4.8%. Chromosome studies showed aneuploidy and a modal number of 45. After subcutaneous transplantation into nude mice, the cells grew into solid large cell non-keratinizing squamous cell carcinomas. By the flow cytometric analysis, the phase fractions of the cells was G1 + G0 = 40.1%, S = 24.9% and G2 + M = 35.0%. The OMC-1 cells produced TA-4 in culture media. TA-4 was also demonstrated immunohistochemically in the original tumor tissue, cultured cells and tumors in nude mice.     

Retinoic acid and interferon-alpha effects on cell growth and differentiation in cervical carcinoma cell lines

OBJECTIVE: To investigate and compare the efficacy of all-trans retinoic acid (RA) and/or interferon-alpha (IFN-alpha) on premalignant and malignant models of cervical cancer. METHODS: Cell growth rate was examined after treatment for 4, 7, and 10 days with RA and/or IFN-alpha of human papillomavirus type 18 (HPV 18)-immortalized endo- and ectocervical cells, nontransformed serum-adapted cells, transformed cells, three adenocarcinoma, and three squamous cell carcinoma cell lines. The effect on epithelial differentiation by RA and IFN-alpha was examined in organotypic culture. Induction of apoptosis was examined by modified terminal transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) and DNA fragmentation. RESULTS: Cell growth rate was inhibited by RA, 84-96% in HPV 18-immortalized endocervical cells, SiHa, and ME180, 0% in OMC-4, and 18-62% in other cell lines; and by IFN-alpha about 75% in SiHa and ME180 and 14-40% in the other cell lines. Combining RA and IFN-alpha increased the antiproliferative effect in premalignant cell lines and some cancer cell lines except OMC-4, SiHa, and HT-3. In rafts, RA treatment reversed human endocervical cell metaplasia and HPV 18-immortalized endo- and ectocervical cell dysplastic epithelial differentiation. Interferon-alpha, not RA, treatment of HPV 18-immortalized endo- and ectocervical cells induced apoptosis. CONCLUSION: Cell growth inhibition by treatment with RA, IFN-alpha, and their combination differentially depends on treatment type and time, cell origin, cell line, and oncogenic state. In a premalignant model of cervical carcinoma, RA reduces dysplastic differentiation and IFN-alpha induces apoptosis. These data confirm that these treatments may be effective for preventing or treating premalignant cervical lesions.     

宫颈鳞状细胞癌ATP-TCA法体外药敏试验与耐药相关蛋白表达的关系

目的:探讨代表不同耐药机制的P糖蛋白(P-gp)、谷胱甘肽S-转移酶(GST-π)、DNA拓扑异构酶Ⅱ(TopoⅡ)、胸苷酸合成酶(TS)在原发宫颈鳞癌组织中的表达及其与临床病理参数的关系;分析三磷酸腺苷生物荧光法体外药敏试验(ATP-TCA)结果与耐药蛋白表达的关系。方法:收集32例宫颈鳞癌患者的新鲜癌组织制成单细胞悬液,采用ATP-TCA法成功检测上述细胞对11种化疗药物(共16种组合)的体外敏感性;采用EnVision二步法免疫组化检测32例宫颈鳞癌组织中P-gp、GST-π、TopoⅡ、TS蛋白的表达,并分析其与临床分期、肿瘤分化程度的关系。结果:耐药蛋白P-gp、GST-π、TopoⅡ、TS在宫颈鳞癌组织中的表达与临床分期、肿瘤分化程度无相关性;耐药蛋白P-gp表达与体外PTX+CBP耐药正相关(P=0.040);耐药蛋白TS表达与体外5-FU、5-FU+MMC、5-FU+DDP耐药正相关(P=0.015,0.012,0.006);TopoⅡ,GST-π蛋白表达与宫颈鳞癌体外耐药均无相关性。结论:体外药敏试验联合免疫组化检测,有可能用于宫颈鳞癌化疗前药敏预测。     

Sensitivity to etoposide in cultured cells from cervical squamous cell carcinoma

The anti-cancer effect of Etoposide was tested in in vitro in cultures of cells taken from a squamous cell carcinoma of the uterine cervix (SKG-IIIb). Growth inhibition was tested by the regrowth assay method, inhibition of DNA synthesis by the uptake of 3H-thymidine, and morphological changes by the method of Limburg et al. The concentrations of Etoposide used were similar to the blood levels recommended for clinical use. The regrowth assay showed that the effective concentration of Etoposide for 50% cell kill was 7.5 micrograms/ml in 2-hour and 1.0 microgram/ml in 24-hour cultures. The 3H-thymidine uptake test showed that a concentration of 13 micrograms/ml for 2 hours or of 3.5 micrograms/ml for 24 hours resulted in 50% inhibition of DNA synthesis. Morphological changes were much greater in the 2-hour cultures at the higher concentration of Etoposide than in the 24-hour cultures at the lower concentration. Investigation of the drug sensitivity by cell kinetics disclosed prolongation of the cell cycle occurring after 96 hours at 1.0 microgram/ml and inhibition of cell cycle progression occurring after 24 hours at 10.0 micrograms/ml and after 4 or 8 hours at 50.0 mu/ml. Thus, the anti-cancer effect of Etoposide on SKG-IIIb depends on both the concentration and exposure time and is related to its ability to inhibit cell growth and DNA synthesis and to cause morphological changes in the cancer cells.     

Biological implications of growth factors on the mechanism of invasion in gynecological tumor cells.

We investigated the effects of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) on migration, invasion and proteinase expression of gynecological cultured cancer cells (SKG-IIIb cervical squamous cell carcinoma, OMC-4 cervical adenocarcinoma, SNG-M endometrial adenocarcinoma and OMC-3 ovarian adenocarcinoma), and whether these growth factors affect thymidine phosphorylase/platelet-derived endothelial cell growth factor expression of tumor cells. Tumor cell migration along a gradient of substratum-bound fibronectin and invasion into reconstituted basement membrane were stimulated by 0.1-10 nM EGF and TGF-alpha in a concentration-dependent manner. The zymography of tumor-conditioned medium showed that the treatment of tumor cells with EGF and TGF-alpha resulted in the increase of type IV collagenases, stromelysin and urokinase-type plasminogen activator which was partly confirmed by immunoblot analysis. The expression of thymidine phosphorylase/platelet-derived endothelial cell growth factor which has angiogenic activity, was also upregulated by these growth factors. These results suggest that EGF and TGF-alpha act as positive regulators on the invasion process of gynecological tumor cells which may be associated with their stimulatory action on the motility of tumor cells, the expression of proteinases secreted by tumor cells and the angiogenic phenotype.     

Glandular cell properties of cell line (HKUS) derived from small cell non-keratinizing squamous cell carcinoma of the uterine cervix

HKUS cell line was established by culturing a uterine cervical small cell non-keratinizing squamous cell carcinoma from a 70-year-old woman. The cells were spindle-like and roundish in shape and in an epithelial cell arrangement. No contact inhibition was observed, and the cells proliferated in multi-layer fashion. Proliferation was quick and more than 250 passages were observed within 4 years after establishment. The chromosome number mode was found in the diploid range, and the chromosomes of stem cells showed a structure abnormality of 45, X, -X. Most HKUS cells had characteristics of glandular cells, and adenocarcinoma was formed when the cells were transplanted into the subepidermis of nude mouse. Some HKUS cells had characteristics of squamous epithelial cells. The HKUS line is regarded as a primitive carcinoma cell line that can differentiate into squamous cell carcinoma and adenocarcinoma.     

Ubenimex (bestatin) inhibits invasion and matrilysin activation of human uterine cervical adenocarcinoma OMC-4 cells

The purpose of the study was to investigate the effect of the aminopeptidase inhibitor ubenimex (bestatin) on the invasive activity of cultured human uterine cervical adenocarcinoma cells. The enzymatic degradation of the extracellular matrix by tumor cells during the invasive process was also examined. The invasion of cervical adenocarcinoma OMC-4 cells into reconstituted basement membrane (Matrigel) was inhi-bited by the presence of bestatin in a concentration-dependent manner. However, bestatin did not have any effect on tumor cell proliferation and migration. The casein zymography of tumor conditioned medium showed that the treatment of tumor cells with bestatin resulted in the drastic reduction of the 19 kDa-enzyme level (matrilysin, active form) and the slight reduction of the 28 kDa-enzyme level (matrilysin, latent form) in OMC-4 cells. The effect of bestatin on matrilysin secreted by OMC-4 cells were also confirmed by immunoblot analysis, and the disappearance of matrilysin in the active form was found. Bestatin inhibited hydrolysing activities towards substrates of aminopeptidases in tumor cells, but did not directly inhibit matrilysin. These results suggest that bestatin may inhibit the invasion of uterine cervical adenocarcinoma OMC-4 cells possibly through the inhibitory mechanisms for production and activation of matrilysin modulated by tumor aminopeptidases.     

The production and characterization of monoclonal antibody, 1C5, reactive with cervical adenocarcinoma of the uterus

A new monoclonal antibody, 1C5, was produced by fusion of spleen cells obtained from mice immunized with CAC-1, a human cell line of cervical adenocarcinoma of the uterus, and NS-1 myeloma cell. The objectives of this study were to obtain moAb that can be used for routine histology and cytology, and to examine the histogenesis of cervical adenocarcinoma. 1. 1C5 reacted with 88% of cervical adenocarcinoma of the uterus, but did not react with cervical squamous cell carcinoma of the uterus and other squamous cell carcinoma. However, 1C5 reacted with some adenocarcinomas, such as endometrial carcinoma of the uterus and ovarial carcinoma. 2. The staining pattern by 1C5 was different, in cervical adenocarcinoma from that in endometrial carcinoma of the uterus, and also different in the endocervical type from that in the endometrioid type of cervical adenocarcinoma. Therefore, 1C5 is useful in distinguishing between two types of adenocarcinoma of the uterus. 3. 1C5 did not react with normal squamous cells or normal columnar cells of the uterine cervix, or with normal endometrial cells of the uterus. However, the columnar cells in a limited area of the squamocolumnar junction were strongly stained with 1C5. 4. 1C5 reacted with ethanol-fixed, and routine formalin-fixed and paraffin-embedded tissue. Thus, 1C5 may be used for clinical diagnosis. 5. 1C5 was found to be IgG1. 6. The molecular weight of the 1C5-defined antigen was 26,000 daltons, and the epitope of the 1C5-defined antigen was carbohydrate moiety. 7. We examined the histogenesis of cervical adenocarcinoma of the uterus by utilizing the reactivity of 1C5.(ABSTRACT TRUNCATED AT 250 WORDS)     

A study of the expression of class II antigen on uterine cervical cancer cells and cell lines

An immunohistochemical method with monoclonal antibody to DR antigen was used to study class II antigens and HLA-DR antigen in 20 patients with uterine cervical cancer. Eight patients had various amounts of DR antigen. Regional infiltrating lymphocytes were also examined with anti-Leu 1, Leu 2a, Leu 3a, and Leu 10. Among the many infiltrating T cells, Leu 3a-positive cells were relatively predominant surrounding the cancer nests which contained DR antigen. Cervical cancer cell lines OMC-1 and OMC-4 both demonstrated DR antigen. Interferon (IFN)-gamma treatment enhanced the expression of DR antigen in OMC-1 and OMC-4. The DR antigen in OMC-1 and OMC-4 were capable of stimulating allogenic lymphocytes in mixed lymphocyte reaction (MLR), and their stimulatory activity was significantly enhanced by IFN-gamma treatment. These results demonstrated the expression of class II antigen, especially DR, on some cervical cancer cells and cell lines and showed that the DR antigen in uterine cancer cell lines can stimulate MLR.     

RNA干扰技术抑制卵巢上皮性癌细胞IGF1R基因表达及增强顺铂敏感性的实验研究

目的 利用RNA干扰(RNAi)技术抑制卵巢上皮性癌(卵巢癌)HO8910PM细胞胰岛素样生长因子1型受体(IGF1R)基因的表达,探讨IGF1R的生物学功能及对顺铂敏感性的影响.方法 将IGF1R基因的特异性小分子干扰RNA(siRNA)、非特异性siRNA分别转染细胞;转染后48h通过实时PCR、蛋白印迹法(western blot)、流式细胞仪分别测定IGF1R mRNA、蛋白的表达及细胞周期变化;转染后24、48、72、96 h通过细胞增殖/毒性检测试剂cell counting kit-8(CCK-8)测定细胞增殖;于转染后24 h给予不同浓度的顺铂作用24 h,通过CCK-8法测定细胞增殖抑制率;于转染后24 h给予10μg/ml顺铂作用24 h,通过流式细胞仪及蛋白印迹法分别检测细胞凋亡和B淋巴细胞白血病/淋巴瘤蛋白2(Bcl-2)蛋白的表达.结果 (1)转染后48 h,IGF1R mRNA和蛋白的表达水平均明显下调,转染后IGF1R mRNA的表达水平下调了85.5%(P＜0.01).(2)转染后48、72、96 h,细胞增殖被明显抑制,细胞增殖活性分别为1.71±0.13、2.32±0.23、2.79±0.28,与未转染及转染非特异性siRNA的对照细胞比较,差异均有统计学意义(P＜0.01).(3)转染后48 h有24.37%的细胞处于G2期(P＜0.05).(4)转染后24 h联合不同浓度的顺铂作用24 h,当顺铂浓度为2.5、5、10、20μg/ml时,细胞增殖被明显抑制,细胞增殖抑制率分别为(25.94±0.08)%、(40.25±0.05)%、(59.48±0.03)%、(74.18±0.08)%,差异均有统计学意义(P＜0.01).(5)在转染siRNA 24 h后给予10μg/ml顺铂作用24 h,可使细胞的凋亡率增加至17.95%(P＜0.05),并使Bcl-2蛋白的表达水平下调.结论 通过RNAi技术可有效抑制IGF1R基因在转录和翻译水平的表达,抑制肿瘤细胞的增殖,出现G2期阻滞,明显提高细胞对顺铂化疗的敏感性.     

An immunohistochemical study on regional immunological response of uterine cervical cancer

An immunohistochemical analysis was performed to detect MHC class I (HLA-ABC) and class II (HLA-DR) antigens expression on cancer cells from 20 patients with carcinoma of the cervix using monoclonal antibodies to HLA-ABC and DR antigens. Locally infiltrating lymphocytes were also examined with anti-Leu 1,-Leu 2a,-Leu 3a, and -Leu 12. Class I and class II antigens expression on cervical cancer cell lines OMC-1 and OMC-4 were examined in the same way, and the effects of Interferon (IFN)-gamma treatment were evaluated with Cell-EIA tests. The results were as follows. 1) Class I antigens were preserved in many cases, but lost in some. 2) Class II antigens were newly expressed in some cases. 3) Among the many infiltrating T cells, Leu 2a-positive cells were predominant in surrounding the cancer nests which preserved class I antigens, and Leu 3a-positive cells were predominant in surrounding the cancer nests which expressed class II antigens. 4) Both OMC-1 and OMC-4 cervical cancer cell lines expressed class I and class II antigens. 5) Cell-EIA tests showed that IFN-gamma treatment enhanced the expression of class I and class II antigens in OMC-1 and OMC-4. These results suggested that the preservation of class I antigens and the expression of class II antigens on cervical cancer cells markedly increase the local immune response in cervical cancer, and IFN-gamma treatment enhances the immune response in vivo.     

Comparative chemosensitivity profiles in four human ovarian carcinoma cell lines measuring ATP bioluminescence

cis-Platinum (DDP) and cyclophosphamide are commonly used for the treatment of ovarian cancer; however, survival remains poor. The degree of cytotoxicity of the standard antineoplastic agents DDP, 4-hydroperoxy-cyclophosphamide (4-OH-CTX), mitomycin C (MITOM C), vincristine (VCR), etoposide (VP-16), 5-fluorouracil (5-FU), cytosine arabinoside (ARA-C), and interferon (IF) in four representative ovarian cancer cell lines was studied using the ATP assay, which measures total cell kill. Cell lines CAOV-3, OVCAR-3, SKOV-3, and BG-1, which were derived from both pretreated and untreated patients, were exposed to six different concentrations for 90 min. On Day 7, intracellular ATP determinations were done. Sensitivity was defined as greater than or equal to 50% cell kill at 0.5 x peak plasma concentration as compared to controls. For 4-OH-CTX and ARA-C, 3 and 0.5 micrograms/ml were chosen as 0.5 x reference values. For each drug in each cell line, a highly reproducible dose-response relationship was observed. CAOV-3 cells were sensitive to all drugs except DDP, ARA-C, and IF, and OVCAR-3 cells to all except DDP and IF. SKOV-3 cells were resistant to all agents except VCR, and BG-1 cells to all except MITOM C and 5-FU. The apparent heterogeneic response to antineoplastic agents observed in the above cell lines underscores the importance of assessing individual patients' sensitivity profiles before treatment.     

Establishment of a cisplatin-resistant human ovarian cancer cell line and the mechanism of resistance

A cisplatin-resistant cell line was established by using KF-1 cells derived from human serous cystadenocarcinoma of the ovary. This resistant cell line, designated "KFr", was capable of proliferating in the presence of 1.0 microgram/ml cisplatin. It had doubling times of 24.8 and 27.2 hr in the presence of 0.5 and 1.0 microgram/ml cisplatin, respectively. The morphologic characteristics of the KFr cells were an enlarged nucleus and prominent nucleoli, unlike the nucleus and nucleoli of the parent KF-1 cells. The degree of resistance to cisplatin of the KFr cells was about 20 times as great as that of the KF-1 cells, with regard to the concentrations of cisplatin required for 50% inhibition of cell proliferation. Although the cisplatin content in the KF-1 cells incubated with 10 micrograms/ml cisplatin was increased in a time-dependent manner, that in the KFr cells reached the plateau level after 1.5 hr incubation with cisplatin. After about 4 hr incubation, the cellular content in the KFr cells was about a half of that in the KF-1 cells. When 0.5 mg cisplatin was administered i.p. to nude mice with KF-1 or KFr tumor, the cisplatin content in the KFr tumor was significantly lower than that in the KF-1 tumor. The KFr cells showed a cross-resistance to melphalan, while no cross-resistance to vincristine or 5-fluorouracil was observed. When 5 microM W-5 or W-7 was added in the presence of concentrations of cisplatin that hardly inhibited cell proliferation, the KFr cell proliferation was markedly inhibited. These findings suggest that the cisplatin resistance in the KFr cells may be due to an impaired cisplatin-transport mechanisms and can be overcome by calmodulin antagonists.     

Effective chemoradiotherapy protocol with 5-fluorouracil for cervical squamous cell carcinoma in vitro

PURPOSE OF INVESTIGATION: 5-Fluorouracil (5FU) is frequently used in concurrent chemoradiotherapy for patients with advanced cervical cancer, although its optimal chemoradiotherapy protocol has not yet been established. In search of an optimal chemoradiotherapy protocol, some in vitro experiments were carried out. METHODS: The radiosensitive human cervical squamous cell carcinoma cell line ME180 was examined to investigate the effects of 5FU on radiosensitivity and the effects of irradiation on 5FU-sensitivity. RESULTS: 5FU dose-dependently enhanced cellular radiosensitivity at therapeutic concentrations. Although high doses of y-ray irradiation significantly reduced the 5FU-sensitivity, a low dose of irradiation at therapeutic doses (< 2.5 Gy) had no effect on 5FU-sensitivity of the irradiated cells. Cells pretreated with 5FU eight hours before irradiation showed significantly higher 5FU-sensitivity than cells concurrently treated with 5FU and irradiation. In contrast, cells treated with 5FU eight hours after irradiation showed significantly lower 5FU-sensitivity than cells concurrently treated with 5FU and irradiation. Moreover, all four post-irradiation surviving subclones obtained from repeatedly irradiated ME180 cells showed significantly lower 5FU-sensitivity than the non-irradiated parent cells. CONCLUSION: 5FU acts as a radiosensitizer for cervical squamous cell carcinoma and 5FU-sensitivity is reduced in irradiated cells. Therefore, 5FU administration immediately before irradiation may be a more effective treatment than concurrent chemoradiotherapy or post-irradiation chemotherapy with 5FU.     

An evaluation of squamous cell carcinoma antigen in patients with cervical squamous cell carcinoma

In a prospective study, serum concentrations of squamous cell carcinoma antigen, a subfraction of tumor antigen (TA-4), were determined by radioimmunoassay from healthy donors, pregnant women, and subjects with various benign and malignant gynecologic diseases. Ninety-six percent of 99 healthy persons including all 52 female controls, the 15 pregnant patients, and all 23 subjects with benign gynecologic tumors, had squamous cell carcinoma antigen levels less than 2.0 ng/ml. Seven of 51 (14%) patients with cervical intraepithelial neoplasia and 16 of 24 (67%) patients with cervical squamous cell carcinoma had squamous cell carcinoma antigen levels greater than 2.0 ng/ml. Declining and rising levels of squamous cell carcinoma antigen, which were determined sequentially in nine cases of cervical carcinoma that were associated with elevated pretreatment levels of squamous cell carcinoma antigen, correlated with regression and progression of the disease. Serial serum levels of squamous cell carcinoma antigen provide a noninvasive means of monitoring the effects of individual therapy in patients with cervical squamous cell carcinoma.     

Secretion of vascular endothelial growth factor in adenocarcinoma and squamous cell carcinoma of the uterine cervix.

OBJECTIVE: To determine whether major differences in vascular endothelial growth factor secretion exist between adenocarcinomas of the uterine cervix compared with squamous cell carcinomas. METHODS: The secretion of vascular endothelial growth factor by eight fresh cervical cancer cell preparations (four adenocarcinomas and four squamous cell carcinomas) and four established squamous cell lines was evaluated using a sensitive enzyme-linked immunosorbent assay in vitro. RESULTS: All cervical tumors secreted significant amounts of vascular endothelial growth factor, and no significant differences between fresh and established squamous cell lines were detectable. In contrast, a highly significant difference in vascular endothelial growth factor secretion was noted between fresh adenocarcinomas (mean = 2712, range between 1700 to 3500 pg/mL/10(5) cells/48 hours) when compared with fresh squamous (mean = 575, range between 200 to 950 pg/mL/10(5) cells/48 hours) or established squamous cervical carcinoma cell lines (mean = 712, range between 400 to 1000 pg/mL/10(5) cells/48 hours) (F-test, P< or =.001). CONCLUSION: These data strongly suggest that major differences in the secretion of vascular endothelial growth factor exist between squamous cell carcinoma and adenocarcinomas of the uterine cervix. Therefore, at least some of the differences in the natural biologic behavior of these two histologic types of cervical cancer, including the propensity for earlier lymphatic and hematogenous metastasis as well as the lower response to radiation treatment, could be related to major differences in the secretion of this powerful angiogenic and immunosuppressive cytokine.