In vivo99mTc-HYNIC-annexin V imaging of early tumor apoptosis in mice after single dose irradiation

Background

Apoptosis is a major mode of hematological tumor death after radiation. Early detection of apoptosis may be beneficial for cancer adaptive treatment. ^99mTc-HYNIC-annexinV has been reported as a promising agent for in vivo apoptosis imaging. The purpose of this study is to evaluate the feasibility of in vivo^99mTc-HYNIC-annexinV imaging of radiation- induced apoptosis, and to investigate its correlation with radiosensitivity.

Methods

Ten days after inoculation of tumor cells in the right upper limbs, the mice were randomly divided into two groups. The imaging group (4 mice each level, 4 dose levels) was injected with 4-8 MBq ^99mTc-HYNIC-annexinV 24 hours after irradiation and imaged 1 hr post-injection, and the mice were sacrificed immediately after imaging for biodistribution analysis of annexin V. The observation group (4 mice each level, 2 dose levels) was only observed for tumor regression post-radiation. The number of apoptotic cells in a tumor was estimated with TUNEL assay.

Results

The ^99mTc-HYNIC-annexin V uptake in E14 lymphoma significantly increased as the radiation dose escalated from 0 to 8 Gy, and significantly correlated with the number of TUNEL-positive cells (r = 0.892, P < 0.001). The Annexin-V uptake and the number of TUNEL-positive cells in El4 lymphoma were significantly greater than those in S180 sarcoma. With 8 Gy, S180 sarcoma tumor showed scanty apoptosis and less shrinkage while El4 lymphoma showed remarkable apoptosis and complete remission.

Conclusion

⁹⁹mTc-HYNIC-annexinV in vivo imaging is a feasible method to detect early radiation-induced apoptosis in different tumors, and might be predictive for radiation sensitivity.     

In vivo imaging of apoptosis

Despite over a decade of intense investigation there is still no routine method for the clinical imaging of apoptosis in oncologic patients. There have been multiple tracers proposed but none as of yet has received FDA approval. Radiolabeled annexin V is one of the few radiotracers that has been widely used in Phase II trials and is still under development. In this review we will first detail the general mechanisms involved with apoptosis and other common forms of cell death. Next we will outline the latest in vivo imaging data in animal models and humans including that obtained with radiolabeled annexin V. It is hoped that improved understanding of the complex biochemical pathways involved with cell death will lead to at least several radiopharmaceuticals with the ability to image apoptosis as part of improving the care and treatment of patients suffering from cancer.     

In vivo imaging of radiation-induced apoptosis in follicular lymphoma patients

PURPOSE: To evaluate (99m)Tc-Annexin-V (TAV) scintigraphy in monitoring radiation-induced apoptotic cell death in follicular lymphoma (FL) patients. PATIENTS AND METHODS: Eleven FL patients (7 female and 4 male; median age, 58 years; range, 42-80 years) with recurrent disease underwent TAV imaging before and 24 hours after the last fraction of the 2 x 2 Gy involved field radiotherapy regimen. Fine-needle aspiration cytology was performed on 5 consecutive days to determine the optimal time window for apoptosis detection and to confirm the apoptotic nature of the response. The TAV scintigraphy (total body studies and SPECT of the irradiated sites) was performed 4 hours after the administration of the radiopharmaceutical. Tumor uptake was scored in a semiquantitative manner as absent (-) weak (+/-), present (+), or intense (++) with corresponding categories for the cytologic slides. Response evaluation was performed after 1 week and 4 weeks both in terms of completeness and speed of remission. RESULTS: Baseline TAV uptake was absent in 6 and weak in 5 patients. Sequential cytology indicated that the optimal time period for apoptosis assessment was between 24 and 48 hours after the last fraction of the 2 x 2 Gy regimen. Baseline cytology was concordant with baseline TAV in all patients. Apoptotic feature appearance (nuclear chromatin condensation, margination and apoptotic body formation) after low-dose irradiation matched the irradiation response in all patients. In all but 1 patient the posttreatment TAV uptake matched the posttreatment cytology. In these 10 patients the cytology and TAV results correlated with the type and onset of the clinical response. CONCLUSION: Tumor (99m)Tc-Annexin-V uptake can be increased after 2 x 2 Gy involved field radiotherapy. This increase was concordant with the appearance of apoptotic morphology as determined by cytology, and correlated with the clinical outcome. Apoptotic cell death can be observed on Day 4 of this regimen and if so predicts a complete remission within 1 week.     

In vivo imaging of tumor response to therapy using a dual-modality imaging strategy

In vivo assessment of the outcome of cancer therapy is hampered by the paucity of imaging probes that target tumors specifically and noninvasively. The importance of such probes increases with the continuous development of chemotherapeutics and the necessity to evaluate their effectiveness in a clinical setting. We have recently reported on a dual-modality imaging probe specifically targeting the underglycosylated mucin-1 tumor-specific antigen (uMUC-1), which is one of the early hallmarks of tumorigenesis in a wide variety of tumors. This probe consists of crosslinked superparamagnetic iron oxide nanoparticles (CLIO) for MR imaging, modified with Cy5.5 dye (for near infrared optical fluorescence imaging (NIRF)), and has peptides (EPPT), specifically recognizing uMUC-1, attached to the nanoparticle's dextran coat. In the present study, we demonstrated that this probe could not only detect orthotopically implanted preclinical models of adenocarcinomas but could also track tumor response to chemotherapy in vivo in real time. Considering the high cost associated with the development and testing of new cancer therapeutics and the need for accurate, noninvasive assessment of their effectiveness, we believe that the developed probe represents a valuable research tool relevant to clinical discovery.     

Quantitative tumor apoptosis imaging using technetium-99m-HYNIC annexin V single photon emission computed tomography.

PURPOSE: Radiolabeled annexin V may allow for repetitive and selective in vivo identification of apoptotic cell death without the need for invasive biopsy. This study reports on the relationship between quantitative technetium-99m- (99mTc-) 6-hydrazinonicotinic (HYNIC) radiolabeled annexin V tumor uptake, and the number of tumor apoptotic cells derived from histologic analysis. PATIENTS AND METHODS: Twenty patients (18 men, two women) suspected of primary (n = 19) or recurrent (n = 1) head and neck carcinoma were included. All patients underwent a spiral computed tomography (CT) scan, 99mTc-HYNIC annexin V tomography, and subsequent surgical resection of the suspected primary or recurrent tumor. Quantitative 99mTc-HYNIC annexin V uptake in tumor lesions divided by the tumor volume, derived from CT, was related to the number of apoptotic cells per tumor high-power field derived from terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) assays performed on sectioned tumor slices. RESULTS: Diagnosis was primary head and neck tumor in 18 patients, lymph node involvement of a cancer of unknown primary origin in one patient, and the absence of recurrence in one patient. Mean percentage absolute tumor uptake of the injected dose per cubic centimeter tumor volume derived from tomographic images was 0.0003% (standard deviation [SD], 0.0004%) at 1 hour postinjection (PI) and 0.0001% (SD, 0.0000%) at 5 to 6 hours PI (P =.012). Quantitative 99mTc-HYNIC annexin V tumor uptake correlated well with the number of apoptotic cells if only tumor samples with no or minimal amounts of necrosis were considered. CONCLUSION: In the absence of necrosis, absolute 99mTc-HYNIC annexin V tumor uptake values correlate well with the number of apoptotic cells derived from TUNEL assays.     

Short communication: Semiquantitative assessment of 99mTc-EDDA/HYNIC-TOC scintigraphy in differentiation of solitary pulmonary nodules--a complementary role to visual analysis

The aim of this study was the assessment of a value of a semiquantitative analysis of scintigrams obtained with (99m)Tc-EDDA/HYNIC-TOC as a radiopharmaceutical (RPH) in differential diagnosis of solitary pulmonary nodules (SPNs), as a method complementary to visual evaluation of scintigrams. MATERIAL AND METHODS: Scintigraphic images of 59 patients (33 males and 26 females between 34 and 78 years of age, mean value, 57) with SPN on chest radiographs (39 malignant and 20 benign) were retrospectively assessed semiquantitatively. Visual scintigram analysis was made earlier, prospectively. Nodule diameters ranged from 1 to 4 (mean 2.2) cm. A single photon emission computed tomography (SPECT) acquisition was performed at 2-4 hours after administration of 740 to 925 MBq of a RPH. Verification of scintigraphic results was based on a pathological examination of tumor samples (histopathology or cytology) and, in some cases, on bacteriological studies. As an additional criterion for tumor benignity, its stable size in a time interval not shorter than 3 years was accepted. A simple, semiquantitative method for assessment of radiopharmaceutical uptake in SPNs was used, based on "count sample" taken from tumor center (T) in relation to radiopharmaceutical concentration in the background (B) measured in the contralateral lung. A criterion for optimal differentiation between malignant and benign nodules (T/B ratio threshold value) was introduced, based on a receiver operating characteristic (ROC) curve. Additionally, a value of T/B ratio was searched for, excluding tumor benignity with high probability. RESULTS: Visual analysis of scintigrams revealed enhanced uptake of RPH at 36 of 39 (92%) sites, corresponding to locations of malignant nodules (including 34 of 35-97% cases of lung cancer). In 13 of 20 (65%) benign nodules, true negative results were obtained. Accuracy of the method equalled 83%. Optimal differentiation between malignant and benign nodules was found for a value of a T/B ratio amounting to 2. The semiquantitative method gave true positive results in 35 of 39 (90%) malignant nodules (as in visual method in 34 of 35-97% cases of lung cancer). True negative results were obtained in 17 of 20 (85%) benign cases. Accuracy of the method reached 88%. A T/B ratio exceeding 4 excluded tumor benignity with high probability. CONCLUSIONS: A simple method, of quantitatively assessing 99mTc-EDDA/HYNICTOC uptake in solitary pulmonary nodules by means of a T/B ratio can play a role that is complementary to the visual evaluation of scintigrams. It improves low specificity of the method in the detection of malignant nodules, without significant reduction of its sensitivity and provides a T/B ratio excluding tumor benignity with high probability.     

Prediction of chemotherapeutic response by Technetium 99m--MIBI scintigraphy in breast carcinoma patients

BACKGROUND: Significance of Technetium 99m ((99m)Tc)-MIBI scintigraphy in the prediction of response to anthracylines and taxanes (both are substrates for P-glycoprotein [P-gp]) as well as relation between (99m)Tc-MIBI uptake and P-gp or MDR1 mRNA expression in tumors were studied in patients with breast carcinoma. METHODS: Forty-six female patients with locally advanced (n = 15) or metastatic (n = 31) breast carcinoma were recruited in this study. Before chemotherapy (epirubicin and cyclophosphamide [n = 20] or decetaxel [n = 26]), (99m)Tc-MIBI scintigraphy was performed to obtain the T/N (tumor to normal tissue) ratios of (99m)Tc-MIBI uptake at 10 minutes (T/N[e]) and at 180 minutes (T/N[d]) after the (99m)Tc-MIBI injection. Expression of MDR1 mRNA and P-gp in tumors (n = 32) were determined by a quantitative real-time polymerase chain reaction and immunohistochemistry, respectively. RESULTS: Clinical significance of T/N(e) and T/N(d) ratios in the prediction of chemotherapeutic response was evaluated using the arbitrary cutoff values of 3.0 for T/N(e) ratios and 2.0 for T/N(d) ratios. Positive predictive value, negative predictive value, and diagnostic accuracy of T/N(d) ratios (81.0%, 96.0%, and 89.1%, respectively) were higher, although statistically not significant, than those of T/N(e) ratios (73.3%, 77.4%, and 76.1%, respectively), and these values were not affected by type of chemotherapy. MDR1 mRNA levels were not significantly different between the lesions with high (> or = 2.0) and low (< 2.0) T/N(d) ratios, but P-gp expression was significantly (P < 0.01) higher in the lesions with low T/N(d) ratios than in those with high T/N(d) ratios. CONCLUSIONS: T/N(d) ratios determined by (99m)Tc-MIBI scintigraphy are useful in the prediction of response to chemotherapy with epirubicin and cyclophosphamide or docetaxel as well as in the in vivo evaluation of P-gp expression status in tumors in patients with locally advanced or recurrent breast carcinoma.     

99mTc-HYNIC-annexinⅤ活体检测单次放疗后肿瘤细胞凋亡

  目的   本研究旨在采用99mTc-HYNIC-annexinⅤ活体检测放疗后肿瘤的凋亡情况,并初步探讨凋亡与照射剂量及肿瘤敏感性的关系。   方法   将EL₄淋巴瘤和S180肉瘤细胞株分别接种于实验小鼠右腋下10 d,随机分成显像组和观察组。显像组不同剂量照射后尾静脉注射99mTc-HYNIC-annexinⅤ,2 h后SPECT显像,取组织称重后分别测量放射性计数,计算每克组织百分注射剂量率（%ID/g）及T/B、T/M放射性比值,应用TUNEL法检测肿瘤凋亡细胞数。观察组照射后观察2周。   结果   EL₄淋巴瘤随照射剂量增加显影逐渐清晰,凋亡细胞数增多,且与%ID/g呈正相关（r=0.892,P < 0.001）;S180肉瘤不明显。相同剂量（0 Gy或8 Gy）照射,EL₄淋巴瘤放射性分布及凋亡细胞数明显高于S180肉瘤。8 Gy照射后,S180肉瘤仅缩小0.1 cm,EL₄淋巴瘤完全消退。   结论   99mTc-HYNIC-annexinⅤ可早期活体检测放疗诱导的肿瘤凋亡。放射诱导的凋亡与疗效呈正相关,检测凋亡有助于判断其对放疗的敏感性,可以作为预后的指标。      

(99m)Tc-sestamibi scintigraphy used to evaluate tumor response to neoadjuvant chemotherapy in locally advanced breast cancer: A quantitative analysis

To evaluate the tumor response to neoadjuvant chemotherapy, (99m)Tc-sestamibi breast scintigraphy was proposed as a quantitative method. Fifty-five patients with ductal carcinoma were studied. They underwent breast scintigraphy before and after neoadjuvant chemotherapy, along with clinical assessment and surgical specimen analysis. The regions of interest on the lesion and contralateral breast were identified, and the pixel counts were used to evaluate lesion uptake in relation to background radiation. The ratio of these counts before to after neoadjuvant chemotherapy was assessed. The decrease in uptake rate due to chemotherapy characterized the scintigraphy tumor response. The Kruskal-Wallis test was used to compare the mean scintigraphic tumor response and histological type. Dunn's multiple comparison test was used to detect differences between histological types. The Mann-Whitney test was used to compare means between quantitative and qualitative variables: scintigraphic tumor response vs. clinical response and uptake before chemotherapy vs. scintigraphic tumor response. The Spearman's test was used to correlate the quantitative variables of clinical reduction in tumor size and scintigraphic tumor response. All of the variables compared presented significant differences. The change in (99m)Tc-sestamibi uptake noted on breast scintigraphy, before to after neoadjuvant chemotherapy, may be used as an effective method for evaluating the response to neoadjuvant chemotherapy, since this quantification reflects the biological behavior of the tumor towards the chemotherapy regimen. Furthermore, additional analysis on the uptake rate before chemotherapy may accurately predict treatment response.     

99Tcm-MDP骨显像肺部病变的定量分析

目的 99 Tcm亚甲基二膦酸盐(99 Tcm-Methylenediphosphonate,99Tcm-MDP)骨显像为肿瘤患者常规检查项目.骨外组织包括肺部各种病变,可不同程度的摄取显像剂.本研究对肺部不同病变异常放射性摄取进行定量分析和精确诊断.方法 收集2012-01-01-2015-05-01山东大学附属山东省肿瘤医院肺部肿瘤胸部异常摄取”Tcm-MDP的患者260例,行常规全身骨显像,按病变性质分为A(单纯肺部肿块78例)、B(胸腔积液55例)、C(胸膜累及54例)、D(胸膜累及合并胸腔积液73例)和E(明确为肋骨转移42例)组.在异常放射性浓集区用感兴趣区(region of interest,ROD技术分别勾画出病侧肋骨(A、B、C和D组避开肋骨转移部位)及肋间(target,T)以及对侧相应正常部位(non target,NT)的总放射性计数,行T/NT和相关计算进行统计学分析.结果 胸部5种不同性质病变的T/NT(x±s)值均＞1.3,5种病变均不同程度摄取99Tcm-MDP,其形态各异.5组肋骨的T/NT,仪E组与其他4组比较差异有统计学意义,余各组间P值均＞0.05.A、B、C和D4组肋间的T/NT,仅AB组差异有统计学意义(P=0.04),余各组间P值均＞0.05.各组的病灶侧肋骨计数(x)减去病灶侧肋间计数(y)与对侧正常侧肋骨计数(z)相比,仅E组与其他4组比较差异有统计学意义,均P值均＜0.05.结论 肋骨转移及不同性质肺部病变均可异常摄取99Tcm-MDP,但其程度及形态有差异;通过定量分析处理,可在一定程度上区别胸部病变的性质.     

In vivo single molecular fluorescence imaging for analysis of pharmacokinetics

Nano-materials are expected for research on molecular imaging of pharmacokinetics. We measured in vivo migration of CdSe nano-particles(Quantum Dots(QDs))conjugated with monoclonal anti-HER2 antibody(trastuzumab)in tumor vessel to breast cancer cells. We established a high resolution in vivo 3D microscopic system for a novel imaging method at single molecular level. The HER2 protein expressed in cancer cells and its dynamics were visualized by QDs in vivo at the spatial resolution of 30 nm. It suggests future utilization of the system in medical applications to improve the drug delivery system to target primary and metastatic tumors for made-to-order treatment. Future innovation in cancer imaging by nano-technology and novel measurement technology will provide great improvement, not only in the clinical field, but also in basic medical science. Advances in nano-biotechnology have great potential to improve prevention, diagnosis and treatment of human disease.     

In vivo modulation of glutathione by buthionine sulfoximine: effect on marrow response to melphalan

The effect of giving buthionine sulfoximine (BSO), 0.0265 g/mouse (6 mM), at 12 and 6 hr before treatment with melphalan--0.0 mg, 3 mg, 6 mg, and 9 mg/kg, was studied in C3H mice, and was compared with control groups that received normal saline 12 and 6 hr before identical melphalan treatment. BSO treatment resulted in depletion of GSH levels in bone marrow, liver, and muscle to 65, 13, and 41% of control levels, respectively. Hematological toxicity was assessed by measurement of CFU-S survival and peripheral white cell counts. CFU-S survival decreased with increasing doses of melphalan, but no difference was observed with BSO pre-treatment. Likewise, WBC counts following melphalan 9 mg/kg, were similar irrespective of BSO pre-treatment. These data suggest that the marrow toxicity seen with melphalan is not worsened by pre-treatment with BSO and that if tumors can be pre-sensitized with BSO, there may be a clinical role for melphalan/BSO drug combination.     

In vivo optical molecular imaging of vascular endothelial growth factor for monitoring cancer treatment.

PURPOSE: Vascular endothelial growth factor (VEGF) expression is a critical component in tumor growth and metastasis. Capabilities to monitor VEGF expression in vivo can potentially serve as a useful tool for diagnosis, prognosis, treatment planning, monitoring, and research. Here, we present the first report of in vivo hyperspectral molecular imaging strategy capable of monitoring treatment-induced changes in VEGF expression. EXPERIMENTAL DESIGN: VEGF was targeted with an anti-VEGF antibody conjugated with a fluorescent dye and was imaged in vivo using a hyperspectral imaging system. The strategy was validated by quantitatively monitoring VEGF levels in three different tumors as well as following photodynamic treatment. Specificity of the molecular imaging strategy was tested using in vivo competition experiments and mathematically using a quantitative pharmacokinetic model. RESULTS: The molecular imaging strategy successfully imaged VEGF levels quantitatively in three different tumors and showed concordance with results from standard ELISA. Changes in tumoral VEGF concentration following photodynamic treatment and Avastin treatment were shown. Immunohistochemistry shows that (a) the VEGF-specific contrast agent labels both proteoglycan-bound and unbound VEGF in the extracellular space and (b) the bound VEGF is released from the extracellular matrix in response to photodynamic therapy. In vivo competition experiments and quantitative pharmacokinetic model-based analysis confirmed the high specificity of the imaging strategy. CONCLUSION: This first report of in vivo quantitative optical molecular imaging-based monitoring of a secreted cytokine in tumors may have implications in providing tools for mechanistic investigations as well as for improved treatment design and merits further investigation.     

Rapid and quantitative assessment of cancer treatment response using in vivo bioluminescence imaging

Current assessment of orthotopic tumor models in animals utilizes survival as the primary therapeutic end point. In vivo bioluminescence imaging (BLI) is a sensitive imaging modality that is rapid and accessible, and may comprise an ideal tool for evaluating antineoplastic therapies. Using human tumor cell lines constitutively expressing luciferase, the kinetics of tumor growth and response to therapy have been assessed in intraperitoneal, and subcutaneous, and intravascular cancer models. However, use of this approach for evaluating orthotopic tumor models has not been demonstrated. In this report, the ability of BLI to noninvasively quantitate the growth and therapeutic-induced cell kill of orthotopic rat brain tumors derived from 9L gliosarcoma cells genetically engineered to stably express firefly luciferase (9LLuc) was investigated. Intracerebral tumor burden was monitored over time by quantitation of photon emission and tumor volume using a cryogenically cooled CCD camera and magnetic resonance imaging (MRI), respectively. There was excellent correlation (r=0.91) between detected photons and tumor volume. A quantitative comparison of tumor cell kill determined from serial MRI volume measurements and BLI photon counts following 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) treatment revealed that both imaging modalities yielded statistically similar cell kill values (P=.951). These results provide direct validation of BLI imaging as a powerful and quantitative tool for the assessment of antineoplastic therapies in living animals.     

In vivo and in vitro invasion in relation to phenotypic characteristics of human colorectal carcinoma cells.

In this study we investigated the tumorigenicity, growth pattern and spontaneous metastatic ability of a series of nine human colorectal carcinoma cell lines after subcutaneous and intracaecal xenografting in nude mice. CaCo2 cells were found to be poorly tumorigenic to non-tumorigenic in either site; the other cell lines were tumorigenic in both sites. SW1116, SW480 and SW620 did not show local invasive in the NCI-H716 and LS174T cells were both invasive in the caecum, but only NCI-H716 was invasive in the subcutis. HT29 and 5583 (S and E) cells were invasive in the caecum and from that site metastatic to the lungs and/or the liver. HT29 and 5583S cells were both invasive in the subcutis, but 5583E cells were not. Of each category of in vivo behaviour in the caecum, one cell line was further investigated with regard to invasion in vitro (into embryonic chick heart fragments), E-cadherin expression in vivo and in vitro and in vitro production of u-PA and t-PA. These parameters were chosen in view of their purported role in extracellular matrix degradation and intercellular adhesion, which are all involved in the invasive and metastatic cascade. Invasion in vitro was not predictive for invasion or metastasis in vivo. In the cell line which showed invasion in embryonic chick heart tissue, heterogeneous E-cadherin expression was observed in vitro together with a relatively high production of u-PA. The non-invasive cell lines showed in vitro homogeneous expression of E-cadherin with a relatively low production of u-PA. In vivo expression of E-cadherin was either absent or heterogeneous. We conclude that: (1) colorectal carcinoma xenografts show site-specific modification of in vivo invasive and metastatic behaviour; (2) invasion in vitro does not correlate with invasion and metastasis in vivo; (3) in vitro non-invasion might be associated with homogeneous E-cadherin expression and low production of u-PA; (4) E-cadherin expression in vitro differs from E-cadherin expression in vivo. The results support the notion that the microenvironment in which cancer cells grow is one of the factors involved in the regulation of invasive and metastatic behaviour.     

Clinical role of Tc-99m-MIBI scintigraphy in non-Hodgkin's lymphoma.

This study was designed to investigate the relationship between Tc-99m-hexakis-2-methoxyisobutylisonitrile (MIBI) scintigraphy and outcome of treatment in patients with non-Hodgkin's lymphoma (NHL). Forty-five patients with NHL were studied with Tc-99m-MIBI before any treatment. Images of the lesions were obtained at 20 min and 2 h after radionuclide administration. Visual semi-quantitative interpretation was performed for Tc-99m-MIBI (grade 0-4) scintigraphy. Patients underwent 3-5 cycles of CHOP chemotherapy with/without involved field radiotherapy for large tumors. Their responses to treatment were evaluated at the end of chemotherapy and during the follow-up period. Forty of 45 patients (89%) showed abnormal uptake of Tc-99m-MIBI. There was no correlation between intensity of MIBI accumulation and response to chemotherapy. However, patients with negative or decreased MIBI activity 2 h after radionuclide administration showed worse response to chemotherapy compared to those with continued MIBI activity. MIBI activity could not predict the development of relapse in the follow-up study. In this study, the number of patients was small and we could not reach definite conclusions. However, we think that MIBI scintigraphy is not valuable for predicting the chemotherapy outcome in patients with NHL.     

Real-time imaging of TRAIL-induced apoptosis of glioma tumors in vivo

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been shown to induce apoptosis in neoplastic cells. While many previous studies have been performed in cell culture, the delivery and efficiency of TRAIL variants in vivo is less well established. Using dual substrate/reporter bioluminescence imaging (Fluc: firefly luciferase-luciferin and Rluc: Renilla luciferase-coelenterazine), we tested the efficacy of TRAIL using replication-deficient herpes simplex virus (HSV) type 1 amplicon vectors in gliomas. The cDNA for complete TRAIL and the extracellular domain of TRAIL (aa 114-281) were cloned into HSV amplicons and packaged into helper virus-free vectors. Both forms of TRAIL induced similar degrees of apoptosis in human glioma cells (Gli36) in culture within 24 h of infection with TRAIL amplicon vectors. Growth of tumors stably transfected with Fluc (Gli36fluc+) was readily monitored in vivo by bioluminescence imaging following luciferin administration. HSV amplicon vectors bearing the genes for TRAIL and Rluc injected directly into Gli36fluc(+)-expressing subcutaneous gliomas revealed peak Rluc activity 36 h after intratumoral injection as determined by coelenterazine injection followed by imaging. TRAIL-treated gliomas regressed in size over a period of 4 weeks as compared to the mock-injected gliomas. These results show the efficacy of vector delivered TRAIL in treating tumors in vivo and offer a unique way to monitor both gene delivery and efficacy of TRAIL-induced apoptosis in tumors in vivo in real time by dual enzyme substrate (Rluc/Fluc) imaging.     

In vivo response of mouse lymphocytes to phytohemagglutinin and colchicine

The response of peripheral mononuclear leukocytes and the systemic tolerance of mice to parenterally administered phytohemagglutinin and colchicine were assessed in 200 animals. The administration of 0.5ml of a solution of purified phytohemagglutinin resulted in the appearance of seemingly immature and significantly enlarged (p<0.005) peripheral mononuclear leukocytes. The appearance of large lymphocytes in peripheral blood was interpreted as evidence for the occurrence of lymphoblastic transformation in vivo. However, no blast cells were observed in the peripheral blood smears. The concomitant administration of colchicine prevented enlargement of the circulating mononuclear lymphocytes. The phytohemagglutinin effect was apparently negated or minimized by the concomitant administration of colchicine. The significance of this observation is unknown.