Gene-viral vectors: a promising way to target tumor cells and express antican cer genes simultaneously

目的：研究一种结合肿瘤基因治疗与美丽治疗优势的新型肿瘤治疗载体系统,即基因-病毒载体系统。方法：利用病毒重组技术将抗癌基因插入肿瘤细胞特异性的增殖病毒基因组中,通过细胞病理作用、荧光显微镜、免疫酶链技术及电镜等技术分别观察病毒的杀伤效应、报告基因绿色荧光蛋白、抗癌基因小鼠白细胞介素12表达量及病毒复制情况。结果：构建了一种新型基因-病毒载体系统,该载体系统腺病毒E1b-55kDa蛋白缺失,保留了腺病毒E1a蛋白。该载体系统具有肿瘤增殖病毒ONYX-015相似功能,即它可在肿瘤细胞内复制及增殖,而在正常细胞内不能复制及增殖,从而特异性杀灭肿瘤细胞。它还具有更大的优势,即该载体系统可携带各种抗癌基因以进一步提高抗肿瘤的疗效。应用该载体系统携带该报告基因绿色荧光蛋白可使绿色荧光蛋白在肿瘤细胞内高效表达,其表达量明显高于传统基因治疗的腺病毒载体系,而在正常细胞内低表达,与传统腺病毒载体系统相似或更低。应用该载体系统携带抗癌基因小鼠白细胞介素12,也产生类似结果,并在电镜中证实该载体系统携带抗癌基因小鼠白细胞介素12可在肿瘤细胞株中复制及增殖。结论：基因-病毒载体是将抗癌基因插入肿瘤增殖病毒基因组,通过肿瘤增殖病毒在肿瘤细胞内特异性复制及增殖,从而数百倍乃至上万倍提高抗癌基因的表达量。它充分利用了肿瘤基因治疗与病毒治疗优势,进一步提高抗肿瘤的疗效,克服了传统基因治疗转染率低、表达量少及靶向性弱等缺点及病毒治疗的杀伤力低的缺点。它将成为肿瘤治疗最有希望的治疗方案之一。     

Peripheral gamma delta T-cell deficit in nasopharyngeal carcinoma

Previous studies identified CD56(+) and CD56(-) subsets of peripheral gamma delta T cells from healthy donors. Both subsets responded to stimulation by a myeloma cell line, XG-7 and undergo vigorous ex vivo expansion in the presence of exogenous IL-2. They are cytotoxic for different tumor targets including nasopharyngeal carcinoma, but they differ from one another in that the CD56(-) subset has an additional growth requirement for IL-7 and exhibited greater cytotoxicity against nasopharyngeal carcinoma (NPC) targets. These immune cells were further shown to retard tumor growth in a nude mice NPC model. To assess if these immune cells might contribute to host defense against NPC, we compared gamma delta T-cell status of NPC patients with healthy donors and survivors who had been in clinical remission of the cancer. It was found that peripheral gamma delta T cells of patients were impaired in their response to the stimulatory effects of XG-7 and exhibited weak or essentially no cytotoxicity for the NPC targets. The deficits were present in early and advanced stages of the cancer but were restored among survivors after successful treatment of the cancer. These findings support a role for peripheral gamma delta T cells in host defense against NPC. It was noted that these immune cells comprise less than 5% of peripheral blood monocytic cells and hence it was not surprising that this component of host defense was breached early in the development of the cancer.     

Factors affecting risk of symptomatic temporal lobe necrosis: significance of fractional dose and treatment time

PURPOSE: To study the factors affecting the risk of symptomatic temporal lobe necrosis after different fractionation schedules. METHODS AND MATERIALS: One thousand thirty-two patients with T1-2 nasopharyngeal carcinoma treated with radical radiotherapy in Hong Kong during 1990-1995 were studied. They were treated at four different centers with similar techniques but different fractionation schedules: 984 patients were given 1 fraction daily throughout (q.d.), and 48 patients were irradiated twice daily (b.i.d.) for part of the course. The median total dose was 62.5 Gy (range 50.4-71.2), dose per fraction was 2.5 Gy (range 1.6-4.2), and overall treatment time (OTT) was 44 days (range 29-70). In addition, 500 patients received supplementary doses for parapharyngeal extension, 113 received booster doses by brachytherapy, and 114 received sequential chemotherapy using cisplatin-based regimes. RESULTS: Altogether, 24 patients developed symptomatic temporal lobe necrosis: 18 from the q.d. group and 6 from the b.i.d. group. The 5-year actuarial incidence ranged from 0% (after 66 Gy in 33 fractions within 44 days) to 14% (after 71.2 Gy in 40 fractions within 35 days). Multivariate analyses showed that the risk was significantly affected by the fractional effect of the product of total dose and dose per fraction (hazard ratio [HR] = 1.04, 95% confidence interval [CI] 1.02-1.05), OTT (HR 0.88, 95% CI 0.80-0.97), and b.i.d. scheduling (HR 13, 95% CI 3-54). Repeating the analyses for patients treated with the q.d. schedules confirmed the independent significance of OTT in addition to the product of total dose and dose per fraction. CONCLUSION: The tentative results suggest that in addition to fractional dose, the OTT also had significant impact on the risk of temporal lobe necrosis, and b.i.d. scheduling increased the hazard further.     

Concomitant chemoirradiation for stage III-IV nasopharyngeal carcinoma in Chinese patients: results of a matched cohort analysis

PURPOSE: To evaluate the toxicity and efficacy of concomitant chemoirradiation (CRT) followed by adjuvant chemotherapy compared with radiotherapy (RT) alone in Chinese patients with locoregionally advanced nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS: Between March 1997 and September 2000, 47 Chinese patients with Stage III (n = 9, 19%) and IV (n = 38, 81%) NPC were treated with by CRT using cisplatin 100 mg/m(2) on Days 1, 22, and 43 of RT, plus adjuvant chemotherapy using cisplatin 80 mg/m(2) for 1 day and 5-fluorouracil 1 g/m(2) for 4 days on Days 71, 99, and 127. These patients were then compared with a cohort of 47 patients treated between 1990 and 1993 with RT alone, who were matched with respect to T stage, N stage, nodal bilaterality, nodal level, and nodal size. The RT techniques were similar in the two groups but different dose and fractionation schemes were used. The median biologic equivalent dose to 2 Gy per fraction delivered to the nasopharynx was 68 Gy in the CRT group and 65.3 Gy in the RT-alone group. RESULTS: The compliance rates were 62% for concomitant chemotherapy and 40% for adjuvant chemotherapy. No treatment-related deaths occurred. At the end of treatment, 96% of the CRT group and 79% of the RT-alone group achieved a complete response (p = 0.013). With a median follow-up of 26 months, the 3-year relapse-free survival, disease-specific survival, overall survival, local relapse-free survival, nodal relapse-free survival, and distant metastasis-free survival rate for the CRT group and the RT-alone group was 62% vs. 44% (p = 0.048), 67% vs. 71% (p = 0.88), 65% vs. 69% (p = 0.93), 87% vs. 75% (p = 0.059), 95% vs. 80% (p = 0.026), and 75% vs. 70% (p = 0.84), respectively. CONCLUSION: Our experience indicates that concomitant CRT improves locoregional control in Chinese patients with locoregionally advanced NPC, but our analyses failed to detect any impact on distant failure and survival. The failure to reduce distant metastasis and improve survival may have related in part to the more advanced disease stage in our patients and the relatively low compliance rate of adjuvant chemotherapy. Our findings suggest caution should be exercised in extrapolating the findings of the Intergroup Study 0099 to Chinese patients, and confirmatory results from prospective randomized studies in the endemic population are needed.     

Is waist circumference a useful measure in predicting health outcomes in the elderly?

OBJECTIVE: To examine the effect of age on the relationship between body mass index (BMI) and waist circumference (WC), and the usefulness of BMI, WC and waist-hip ratio (WHR) in predicting mortality and cardiovascular risk in the elderly population. DESIGN: Longitudinal observational study of 36 months duration. SUBJECTS AND METHOD: A stratified random sample of 2,032 Chinese subjects (990 male, 1,033 female) mean age (s.d.) 80.1 (7.5), interviewed and examined at baseline and after 36 months. Deaths and presence of diabetes mellitus and hypertension were documented. A younger data set of 1,010 subjects (500 male, 510 female), mean age (s.d.) 45.5 (11.6), was used for comparison of the BMI-WC relationship between younger and older subjects. In predicting outcomes using different values of BMI, WC and WHR, receiver operating characteristic curve analysis was used to derive cut-off values with optimal sensitivity and specificity, and the likelihood ratios for mortality, diabetes and hypertension for different anthropometric values were plotted. RESULTS: The waist circumference values corresponding to BMI values of 25 and 30 kg/m(2) were higher in elderly (92 and 103 cm for men; 88 and 99 cm for women) compared with younger subjects (85 and 97 cm for men; 78 and 88 cm for women). BMI and WC are inversely associated with mortality, in both men and women, positively associated with diabetes in men but not in women. WC was positively associated with hypertension in men and women. WHR was not associated with any outcome measures. The anthropometric measurement at the point of intersection of the likelihood curves for mortality and diabetes may be considered the optimum value, being BMI=21 kg/m(2) for men and 25 kg/m(2) for women, WC between 80 and 85 cm, and WHR 0.88-0.90. CONCLUSION: Waist measurement values for predicting health outcomes in elderly people aged 70 y and over are different compared with younger subjects, and have similar predictive accuracy compared with body mass index. Waist-hip ratio is not a useful predictor.     

乙肝病毒表面抗原大蛋白与HBV复制状况的相关分析

目的:通过检测慢性乙肝(chronic hepatitis B,CHB)患者血清中乙肝病毒表面抗原大蛋白(large surface protein,LHBs)、HBV DNA以及乙肝病毒标志物(HBsAg/HBsAb、HBeAg/HBeAb、HBcAb,简称HBV-M)模式测定,探讨LHBs与HBV DNA及HBV-M模式间的关系,研究LHBs反应HBV复制情况的可靠性,揭示HBeAg阴性乙肝患者检测LHBs的临床意义。方法:采用酶联免疫吸附试验(ELISA)对LHBs和乙型肝炎抗原抗体五项进行检测;采用荧光定量PCR方法对HBV DNA进行检测。结果:534份乙肝患者HBV DNA、LHBs、乙型肝炎抗原抗体五项的检测结果显示:LHBs阳性与HBeAg阴性间测定结果差异有统计学意义(P=0.001,χ2=10.847),不同HBV-M模式的HBV DNA与LHBs检出结果差异有统计学意义(P<0.001,χ2=37.8761)。结论:LHBs是从蛋白水平反应HBV感染者体内病毒复制程度的可靠指标,血清中的LHBs与HBVDNA具有较好的相关性,尤其是HBeAg阴性患者LHBs检测可作为体内病毒复制及预后判断的良好血清学指标。     

Dose-Tumor Response for Carcinoma of Cervix: An Analysis of 594 Patients Treated by Radiotherapy

This is a retrospective study of 594 histologically proven carcinomas of the uterine cervix treated with radiotherapy alone between January 1970 and December 1986. The age of this group of patients ranged from 22 to 86 years, and the median age was 57 years. There were 544 (91.6%) patients with squamous carcinoma and 36 (6.1%) with adenocarcinoma. There were 24 (4.0%) patients who were treated by two sessions of intracavitary brachytherapy only using intrauterine tandem and vaginal ovoids; 513 (86.4%) patients received whole pelvis irradiation followed by two sessions of brachytherapy at 1-week intervals, with or without additional boost to the parametrium. The dose to point A ranged from 40 to 100.9 Gy for the patients with stage IB to IIIB disease. The 5- and 10-year survival for stages IB, IIA, IIB, IIIA, and IIIB were 90.0, 82.1, 72.0, 50.0, 51.5, and 86.9, 71.0, 67.5, 41.7, and 46.9%, respectively. There was no long-term survivor for stage IV disease; the median survivals for patients with stages IVA and IVB were 15.2 and 9.3 months, respectively. Dose response was demonstrated for stages IIB and III tumors; dose to point A greater than 85 Gy was associated with better central control (P = 0.0036 and 0.0234, respectively). However, further increase in dose to point A beyond 85 Gy was not associated with improvement in central control (P = 0.3128 and 0.3394, respectively, for stages IIB and III). It was also found that the occurrences of rectosigmoid and bladder complications were correlated with the rectal and point A dose. Thus, for these patients, there is no need to increase the dose to point A beyond 85 Gy so that the risk of radiation sequelae can be cut down.     

Comparative efficacy of three 5-HT3 antagonists (granisetron, ondansetron, and tropisetron) plus dexamethasone for the prevention of cisplatin-induced acute emesis: a randomized crossover study

The purpose of this study was to compare the antiemetic efficacy of three 5-HT3 antagonists (granisetron, ondansetron, tropisetron) plus dexamethasone for the prevention of acute emesis induced by high-dose cisplatin chemotherapy. This was a randomized, open label, crossover study. Recruited into the study were 94 chemotherapy-naive patients of whom five were excluded because chemotherapy was not given, noncisplatin regimen was used instead, or presence of anticipatory vomiting. The remaining 89 evaluable patients were mostly (86.5%) male, and were all treated for head and neck cancers. The antiemetic regimens consisted of 1) granisetron 3 mg i.v. and dexamethasone 20 mg i.v. on day 1 (GRADEX); 2) tropisetron 5 mg i.v. and dexamethasone 20 mg i.v. on day 1 (TRODEX); and 3) ondansetron 8 mg i.v. and dexamethasone 20 mg i.v. to be followed by ondansetron 8 mg p.o. x 2 on day 1 (ONDEX). Patients were randomized to receive one of the three regimens in the first cycle, and treatment was crossed over to the other two regimens in subsequent cycles. Antiemetic efficacy was assessed using self-report diaries recording the number of vomiting episodes as well as duration and severity of nausea within the first 24 hours. Complete response was defined as no vomiting with or without mild nausea, and major response was defined as one vomiting episode and/or moderate to severe nausea. Major efficacy refers to either complete or major response. A total of 219 cycles was given to 89 patients: 16 received one cycle only, 16 received two cycles, and 57 received three cycles. No carryover effects were observed between cycles. Using pooled data from all cycles, the complete response rates to GRADEX, TRODEX, and ONDEX were 81%, 68%, and 71%, respectively (p = 0.11); the corresponding major efficacy rates were 91%, 93%, and 86%, respectively (p = 0.36). When only the first cycle was considered, the complete response rates to GRADEX, TRODEX, and ONDEX were 81%, 75%, and 74%, respectively (p = 0.58); the corresponding major efficacy rates were 92%, 94%, and 84%, respectively (p = 0.38). Analysis of the crossover data showed that the majority of patients achieved complete response or major efficacy with the different pairs of regimens, and there were no significant differences between different regimens in terms of complete response or major efficacy. The only exception was GRADEX versus TRODEX, in which 15.5% of patient achieved complete response with GRADEX as compared with 1.7% with TRODEX (p = 0.025). The majority of patients (53%) did not report any preference, whereas 14% preferred GRADEX, 15% preferred TRODEX, and 18% preferred ONDEX. The three 5-HT3 antagonists, when used in combination with steroids, had similar major efficacy for prophylaxis against cisplatin-induced acute emesis. Although GRADEX was superior to TRODEX in terms of complete response, this may not be of clinical significance. The choice of antiemetic regimens should therefore depend on patient preference and drug cost.     

Potent antitumor efficacy of an E1B 55 kDa-deficient adenovirus carrying murine endostatin in hepatocellular carcinoma

Data from clinical trails have shown that the antitumoral effect of ONYX-015, an E1B 55kDa-deficient adenovirus, as monotherapy is insufficient. To enhance its efficiency, CNHK200-mE, another E1B 55kDa-deficient adenovirus armed with a mouse endostatin gene was constructed and its antitumoral activities against hepatocellular carcinoma （HCC） in vitro and in vivo were investigated. The selective replication and cytotoxicity of CNHK200-mE in Hep3B and HepGII cells independent of p53 status were confirmed via TCID50 and 3-（4,5dimetylthiazol）-2,5-diphenyltetrazolium bromide （MTT） assays. Potent tumor growth suppression on SMMC-7721 xenografts in nude mice was observed and a synergistic effect of the carrier virus and the therapeutic gene was suggested. Moreover, in comparison with the nonreplicative adenovirus carrying the same therapeutic gene, amplified transgene expression of mouse endostatin in vitro and in vivo were confirmed by Western blotting and ELISA assay. The effective angiogenesis inhibition and replication of CNHK200-mE in nude mice xenografts were demonstrated by immunohistochemistry. In conclusion, the recombinant adenovirus CNHK200-mE is a replication-competent oncolytic virus mediating high expression of therapeutic gene. Because CNHK200-mE is capable of replicating in and lysing HCC cells selectively with effective tumor growth suppression and antiangiogenic activity on HCC xenografts in nude mice, it holds good potential for the treatment of HCC.