[Laryngeal undifferentiated soft-tissue sarcoma: a case report and review of literature]

Patient presented as a 74-year-old male complaining of hoarseness. Electronic laryngoscope showed a neoplasm whose size was about 1.0 cm×0.5 cm×0.5 cm at anterior commissure. A surgery was conducted to excise the neoplasm en bloc. The histopathological and immunohistochemistry examination suggested inflammatory myofibroblastic tumor. A month later, the patient presented with dyspnea and blood-stained sputum. CT scan of neck showed an occupation lesions under glottis. A tracheotomy and a CO₂ laser surgery was conducted due to patient's will. The histopathological and immunohistochemistry examination suggested undifferentiated sarcoma. We advised him keeping a tracheal cannula to receive further treatment such as radiotherapy or chemotherapy in oncology department, but the patient was not compliant with care instructions for personal reason. He was readmitted 2 months later for dyspnea after plugging the tube. Electronic laryngoscope showed a large neoplasm occupied the laryngeal vestibule, covering the glottis. CT and MRI scan showed the lesion involved spaces of supraglottic, glottic, subglottic and soft tissue around larynx. Hence, a total laryngotomy and bilateral functional neck dissection was conducted. The histopathological examination agreed with the former one. Three weeks later, the skin around his tracheal cannula swelled,ulcerated and pyorrheal. After 10 days of dressing change, patient died of uncontrolled infection.

High-resolution microendoscopy for esophageal cancer screening in China: A cost-effectiveness analysis

AIM

To study the cost-effectiveness of high-resolution microendoscopy (HRME) in an esophageal squamous cell carcinoma (ESCC) screening program in China.

METHODS

A decision analytic Markov model of ESCC was developed. Separate model analyses were conducted for cohorts consisting of an average-risk population or a high-risk population in China. Hypothetical 50-year-old individuals were followed until age 80 or death. We compared three different strategies for both cohorts: (1) no screening; (2) standard endoscopic screening with Lugol's iodine staining; and (3) endoscopic screening with Lugol's iodine staining and an HRME. Model parameters were estimated from the literature as well as from GLOBOCAN, the Cancer Incidence and Mortality Worldwide cancer database. Health states in the model included non-neoplasia, mild dysplasia, moderate dysplasia, high-grade dysplasia, intramucosal carcinoma, operable cancer, inoperable cancer, and death. Separate ESCC incidence transition rates were generated for the average-risk and high-risk populations. Costs in Chinese currency were converted to international dollars (I$) and were adjusted to 2012 dollars using the Consumer Price Index.

RESULTS

The main outcome measurements for this study were quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER). For the average-risk population, the HRME screening strategy produced 0.043 more QALYs than the no screening strategy at an additional cost of I$646, resulting in an ICER of I$11808 per QALY gained. Standard endoscopic screening was weakly dominated. Among the high-risk population, when the HRME screening strategy was compared with the standard screening strategy, the ICER was I$8173 per QALY. For both the high-risk and average-risk screening populations, the HRME screening strategy appeared to be the most cost-effective strategy, producing ICERs below the willingness-to-pay threshold, I$23500 per QALY. One-way sensitivity analysis showed that, for the average-risk population, higher specificity of Lugol's iodine (> 40%) and lower specificity of HRME (< 70%) could make Lugol's iodine screening cost-effective. For the high-risk population, the results of the model were not substantially affected by varying the follow-up rate after Lugol's iodine screening, Lugol's iodine test characteristics (sensitivity and specificity), or HRME specificity.

CONCLUSION

The incorporation of HRME into an ESCC screening program could be cost-effective in China. Larger studies of HRME performance are needed to confirm these findings.

Efficacy of peripheral blood stem cell transplantation versus conventional chemotherapy on anaplastic large-cell lymphoma:a retrospective study of 64 patients from a single center

Anaplastic large-cell lymphoma (ALCL) is characterized by frequently presenting adverse factors at diagnosis. Many groups believed aggressive treatment strategies such as autologous stem cell transplantation brought survival benefit for ALCL patients. However, few compared these approaches with conventional chemotherapy to validate their superiority. Here, we report a study comparing the efficacy of peripheral blood stem cell transplantation (PBSCT) and conventional chemotherapy on ALCL. A total of 64 patients with primary systemic ALCL were studied retrospectively. The median follow-up period was 51 months (range, 1–167 months). For 48 patients undergoing conventional chemotherapy only, the 4-year event-free survival (EFS) and overall survival (OS) rates were 70.7% and 88.3%, respectively. Altogether, 16 patients underwent PBSCT, including 11 at first remission (CR1/PR1), 3 at second remission, and 2 with disease progression during first-line chemotherapy. The 4-year EFS and OS rates for patients underwent PBSCT at first remission were 81.8% and 90.9%, respectively. Compared with conventional chemotherapy, PBSCT did not show superiority either in EFS (P = 0.240) or in OS (P = 0.580) when applied at first remission. Univariate analysis showed that patients with B symptoms (P = 0.001), stage III/IV disease (P = 0.008), bulky disease (P = 0.075), negative anaplastic lymphoma kinase (ALK) expression (P = 0.059), and age ≤ 60 years (P = 0.054) had lower EFS. Furthermore, PBSCT significantly improved EFS in patients with B symptoms (100% vs. 50.8%, P = 0.027) or bulky disease (100% vs. 52.8%, P = 0.045) when applied as an up-front strategy. Based on these results, we conclude that, for patients with specific adverse factors such as B symptoms and bulky disease, PBSCT was superior to conventional chemotherapy in terms of EFS.

Expressions of the γ2 chain of laminin-5 and secreted protein acidic and rich in cysteine in esophageal squamous cell carcinoma and their relation to prognosis

Previous studies have shown that the expressions of the γ₂ chain of laminin-5 and secreted protein acidic and rich in cysteine (SPARC) play important roles in oncogenesis and the development of carcinoma. To assess the expressions of laminin-5 γ₂ chain and SPARC in esophageal squamous cell carcinoma (SCC), and to clarify the prognostic significance of the expressions of laminin-5 γ₂ chain and SPARC in esophageal SCC, we detected the expressions of laminin-5 γ₂ chain and SPARC in cancer tissue and corresponding normal mucosa from 116 patients with advanced (stages II–IV) esophageal SCC using the tissue microarray-based immunohistochemistry and analyzed the correlation of the expressions with clinicopathologic characteristics and survival. We found that in normal esophageal tissues, laminin-5 γ₂ chain was expressed in the basement membrane, whereas in esophageal SCC tissues, laminin-5 γ₂ chain was expressed in the cytoplasm of carcinoma cells, with a positive rate of 72.4%. SPARC was not detected in normal esophageal mucosa, but was expressed in stromal fibroblasts in 84.6% of esophageal SCC cases and in cancer cells in 7.8% of esophageal SCC cases. There was a significant correlation between laminin-5 γ₂ chain and stromal SPARC expression in esophageal SCC (Spearman' s rho = 0.423, P < 0.001). The expressions of both laminin-5 γ₂ chain and stromal SPARC were correlated with survival (P = 0.032 and P = 0.034, respectively). In stage-II esophageal SCC, the expression of laminin-5 γ₂ chain was significantly correlated with survival (P = 0.023), while the expression of SPARC was not significantly correlated with survival (P = 0.154). Patients with elevated levels of laminin-5 γ₂ chain and SPARC expressions had a poorer prognosis than did those lacking elevated levels of laminin-5 γ₂ chain expression and/or elevated levels of SPARC expression (P = 0.001). In stage-II esophageal SCC, patients with elevated levels of laminin-5 γ₂ chain and SPARC expressions had a poorer prognosis (P < 0.001). These results suggest that laminin-5 γ₂ chain and SPARC may play roles in the progression of esophageal SCC and their simultaneous expression is correlated with poorer prognosis, especially in patients with stage-II SCC.

[Differences between clinical response and pathologic response of breast cancer after neoadjuvant chemotherapy]

OBJECTIVE

to investigate the pathologic basis of the difference between clinical response and pathologic response of breast carcinoma after neoadjuvant chemotherapy.

METHODS

two hundred and nine cases of breast cancer with neoadjuvant therapy were analyzed and clinical data were collected from June, 2005 to December, 2007. All patients had core needle biopsy taken before neoadjuvant chemotherapy and were operated within 4 weeks after neoadjuvant chemotherapy. Clinical examination, X-ray of breast and/or B ultrasonography of primary breast focus were taken before and after neoadjuvant chemotherapy. Clinical responses of breast primary focus were evaluated according to RECIST (response evaluation criteria in solid tumors) version 1.1.Pathologic responses of breast primary focus were evaluated according to Miller and Payne (MP) grading system. SPSS 15.0 software was used to statistical analysis.

RESULTS

(1) Clinical responses basing on clinical examination showed complete response, partial response, stable disease and progressive response, in 33, 124, 41 and 11 cases respectively. (2) Eighty-seven cases had X-ray of breast taken before and after neoadjuvant chemotherapy. Clinical response basing on X-ray, showed complete response, partial response and stable disease in 8, 42 and 37 cases respectively. (3) Pathologic responses of breast primary focus were as MP1 (14 cases), MP2 (35 cases), MP3 (106 cases), MP4 (36 cases) and MP5 (18 cases). (4) The clinical response basing on clinical examination were related to the pathologic response (χ(2) = 33.668, P = 0.001); and the clinical response basing on X-ray of breast were also related to the pathologic response (χ(2) = 22.404, P = 0.004). (5) The pathologic basis of the difference between the pathologic response and the clinical response basing on X-ray of breast were: embolism of carcinoma, mucinous carcinoma, intraductal carcinoma with ossifying-type calcification, nodular fibrosis and others.

CONCLUSIONS

the clinical response may be related to the pathologic response. The difference between the two may be caused by pathologic changes. Some benign and malignant pathologic changes may contribute to the under-estimation of clinical response over pathologic response; whereas embolism of carcinoma may contribute to the over-estimation of clinical response over pathologic response.

[Diagnostic value of transbronchial needle aspiration combined with transesophageal endoscopic ultrasound-guided fine needle aspiration in mediastinal and pulmonary hilar lesions]

OBJECTIVE

To evaluate the value of transbronchial needle aspiration (TBNA) combined with transesophageal endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in the diagnosis of mediastinal and pulmonary hilar lesions as well as in the lymph node staging (N staging) of lung cancer.

METHODS

129 patients with mediastinal and pulmonary hilar lesions underwent either TBNA or EUS-FNA with cytological needle aspiration. The samples obtained from TBNA or EUS-FNA were examined by both cytologiy and histopathology.

RESULTS

Of the 129 patients, 59 underwent TBNA and 70 EUS-FNA. The diagnostic rate were 84.7% (50/59) by TBNA and 94.3% (66/70) by EUS-FNA, resepectively. The diagnosis of 116 (89.9%) patients were confirmed by either TBNA or EUS-FNA. The pathological and cytological diagnostic rates were 92.2% (107/116) and 88.0% (102/116), resepectively. The diagnostic rate was elevated by 8.4% (9/107) through pathological examination. The histological classification rates by cytological and pathological examination were 73.8% (76/116) and 89.3% (92/103), respectively. The diagnostic rate of histological classification was elevated by 35.5% (27/76) through pathological examination.

CONCLUSION

The combination of TBNA and EUS-FNA can improve the diagnostic rate for wider mediastinal and pulmlonary hilar lesions. Pathological examination of the samples obtained from the TBNA and EUS-FNA can elevate not only the rate of diagnosis but also the rate of histological classification.

Primary non-Hodgkin lymphomas in the small and large intestine: clinicopathological characteristics and management of 40 patients

To investigate the clinicopathological characteristics and optimal treatment modalities of primary non-Hodgkin lymphoma (NHL) in the small and large intestine. Forty patients with primary NHL in the small and large intestine were studied retrospectively. All cases were reclassified according to the World Health Organization (WHO) classification of lymphoma in 2001. Fourteen patients had primary disease in the small intestine, which were all of B-cell origin with diffuse large B-cell lymphoma (DLBCL) diagnosed in 5 of 14 (35.7%) patients and mucosa-associated lymphoid tissue (MALT) lymphoma in 8 of 14 (57.1%) patients. Ileum was the most commonly involved site (8 of 14 patients, 57.1%), followed by jejunum (2 of 14 patients, 14.3%) and duodenum (1 of 14 patients, 7.1%). Twenty-five patients had primary colorectal lymphoma, with B-cell origin accounting for 92.0% and T-cell origin for 8.0% of these patients. The ileocaecal region has the highest involved rate (13 of 25 patients, 52.0%), followed by colon (7 of 25 patients, 28.0%) and rectum (3 of 25 patients, 12.0%). Compared with surgery alone, post-operation chemotherapy or chemoradiotherapy can significantly improve DLBCL patients' event-free survival (EFS). However, no post-operation treatment modality can improve OS or EFS for patients with MALT lymphoma. B-cell lymphoma is the most common pathological type of intestinal lymphomas. Chemotherapy-containing treatment modality is an effective way to improve intestinal lymphoma patients' EFS, especially for those with DLBCL subtype.

[Application of flow cytometric immunophenotypic analysis in the diagnosis of malignant lymphoma]

OBJECTIVE

To explore the value of flow cytometric immunophenotyping (FCI) in the diagnosis and differentiated diagnosis of lymphoma and explain the immunophenotypic features and differences of malignant lymphoma.

METHODS

Seventy four fresh samples of suspicious lymphoma were collected from Nov. 2004 to Aug. 2006. Each sample was individually evaluated by FCI. The results were analyzed and compared with the histopathological diagnosis.

RESULTS

Among the 74 cases, the FCI data consisted with the final morphological diagnosis in 61 cases (82.4%). For the diagnosis of B and T non-Hodgkin's lymphoma (NHL), thymoma, carcinoma and benign lesions of lymph node, the concordance between FCI data and morphological diagnosis were 93.5%, 100%, 100%, 100% and 81.3%, respectively.

CONCLUSION

Multi-parameter FCI analysis can provide important information and help for diagnosis of lymphoma. It is an assistant but necessary approach for the diagnosis and differential diagnosis of lymphoma.

[Expression of fascin and cytokeratin 14 in esophageal squamous cell carcinoma]

OBJECTIVE

To investigate the expression of fascin and cytokeratin 14 (CK14) in human esophageal squamous cell carcinoma (ESCC) and the association of these two proteins with ESCC malignant progression and the possibility of application of these 2 proteins in the diagnosis of ESCC.

METHODS

A tissue microarray composed of the representative regions of ESCC and corresponding normal epithelium was constructed. Immunohistochemistry was conducted to examine the expression of fascin and CD14 in 116 specimens of ESCC and the normal tissues near the cancerous tissues. The relation of these two proteins with the invasive depth, node involvement, differentiated grade, pTNM stages was analyzed. Disease-free survival analysis was carried out using Kaplan-Meier method. The correlation of the two proteins was analyzed using Spearman's correlation test. ESCC cells of the lines EC9706, TE12, COLO-680N, KYSE510, KYSE450, KYSE410, KYSE180, KYSE150, KYSE140, KYSE70, KYSE30, and YES2 were cultured and underwent SDS-PAGE and Western blotting to examine the expression of fascin and CD14. And the correlation of the two proteins with the characteristics of the cell lines was analyzed too.

RESULTS

Fascin and CK14 were negative in the normal esophageal epithelia except in the basal cells. The positive rates of fascin and CK14 in the ESCC cells were 79.3% and 67.0% respectively. The positive rate of either fascin or CK14 was 86.2%. The expression rates of fascin and CK14 in well- and moderately-differentiated ESCCs were significantly higher than that in the poorly-differentiated ones (P = 0.054 and P < 0.01). The patients with positive expression of fascin and those with negative expression of CK14 had a poorer survival in comparison with those with negative fascin expression and those with positive CK14 expression respectively, however, without statistical significances (P = 0.8980 and P = 0.2610). The positive rates of fascin in the well-, moderately-, and poorly- differentiated ESCCs were 87.1%, 83.9%, and 62.1% respectively (P = 0.054). The positive rates of CK14 in the well-, moderately-, and poorly-differentiated ESCCs were; 87.1%, 76.4%, and 27.6% respectively (P < 0.01). The prognosis was not significantly correlated with the expression of both proteins (P = 0.8980 and P = 0.2610). There was an significantly positive correlation between the expression levels of these 2 proteins (r = 0.487, P < 0.01). Fascin was highly expressed in most of the ESCC lines, except in the slowly growing and weakly migrating TE12 line. High expression of CK14 was only seen in the line KYSE180.

CONCLUSION

Fascin and CK14 may play important roles in the carcinogenesis and progression of ESCC. Combination of fascin and CK14 would be valuable markers in diagnosis of ESCC.

[Expression of annexin I in different histological types of carcinomas]

OBJECTIVE

To investigate the expression of annexin I in esophageal squamous cell carcinoma (SCC) and carcinomas of other histological types in order to analyze the correlation between the expression of annexin I and carcinogenesis.

METHODS

First, a set of tissue microarray was established, which consisted of SCC from the esophagus (208 cases), lung, larynx, cervix, and external genital organs; adenocarcinomas from the lung, stomach, colon and rectum, liver, pancreas, breast, thyroid and kidney with 30 cases in each group, meanwhile, the corresponding normal tissue was also obtained for control. Immunohistochemistry was used to detect the expression of annexin I in different types of carcinomas and the corresponding normal controls from different organs. The correlation between the expression of annexin I and the clinicopathological feature was analyzed and compared, which included age, gender, differentiation grade and lymph node metastasis.

RESULTS

It was found that the expression of annexin I was decreased in esophageal SCC, when compared with normal esophageal squamous epithelia (P < 0.001), the similarity was also found in SCC of the lung, larynx and cervix. However, though negative in normal epidermis, annexin I expression was detected in some cases with SCC from external genital organs. Annexin I was found to be overexpressed in adenocarcinomas of the lung, stomach, colon and rectum, liver, pancreas, breast, thyroid and kidney, particularly very strong expression of annexin I was seen in lung adenocarcinoma, uterine endometrioid adenocarcinoma and ovarian serous adenocarcinoma. Interestingly, it was found to be positive in all thyroid papillary carcinomas, but negative in all normal thyroid glands. However, annexin I expression was found to be negative in all hepatocellular carcinoma and normal hepatocytes; and it was only detected in myoepithelium of normal breast tissue, but not in ductal luminal cells, and rarely in infiltrating ductal adenocarcinoma. In SCC, annexin I expression was stronger in well differentiated ones than that in the poorly differentiated ones. However, contrasting with SCC, in the adenocarcinomas from different organs, annexin I expression was much stronger in poorly differentiated ones than that in the well differentiate ones, especially in the adenocarcinomas from stomach, colon and rectum, pancreas, ovarian and kidney.

CONCLUSION

Annexin I expression is quite different among different types of carcinomas, and is correlated with histopathological type and differentiation grade. Further study is needed to investigate its role in the carcinogenesis.

[A retrospective analysis of anaplastic thyroid carcinoma]

OBJECTIVE

To summarize the new knowledge of the anaplastic thyroid carcinoma (ATC).

METHODS

The clinical data of 58 patients (35 men, 23 women, aged 28 to 79 years) with ATC that were treated with various therapeutic modalities from 1981 to 2005 were retrospectively analyzed. Among them, 25 patients received surgery alone (SA group) and 33 received surgery plus radiation (S + R group). The dosage of postoperative radiotherapy was 40-70 Gy. Four patients received biopsy, 24 received palliative surgery, and 30 received radical surgery. Only 2 patients received complete chemotherapy.

RESULTS

ATC invaded trachea in 40 patients (69.0%), esophagus in 32 patients (55.2%), and carotid in 17 patients (29.3%). The cervical lymph node metastases occurred in 19 patients (32.8%). The overall 1-year survival rate was 37.8%, 3-year survival rate 31.2%, and 5-year survival rate 25.9%. The 5-year survival rate was 37.8% in S + R group but was only 9.9% in SA group (P = 0.0000). The 5-year survival rate was 41.4% in radical surgery subgroup but was only 12.4% in palliative surgery subgroup (P = 0.0023). In < or = 45-year-old subgroup (n = 4), the 5-year survival rate was 50.0%; however, in > 45-year-old subgroup, it was only 21.3%. In postoperative radiation < 60 Gy subgroup , the 5-year survival rate was 19.3%; however, in > or = 60 Gy group, it was 53.7% (P = 0.0000). Among all the 58 patients, some patients received palliative surgery because of tumor invasion in trachea (n = 16, 27.6%), esophagus (n = 8, 13.8%), carotid (n = 8, 13.8%), and other sites (n = 13, 22.4%). Twenty-four patients (61.5%) died of localrelapse, 2 (5.1%) of cervical lymphnode failure, 9 (23.1%) of metastasis, and 4 (10.3%) of other reasons.

CONCLUSIONS

The prognosis of ATC is poor. Radical surgery and postoperative radiation > or = 60 Gy can improve the survival rate. Tumor invasion in trachea, esophagus, and carotid are the main reasons of palliative surgery. Local relapse is lethal.

Detection of tumor-associated biomarkers in precancerous lesions of esophagus

AIM: To investigate the expressions of annexin I, Grp94, p53, Ki-67 in esophageal squamous cell carcinoma (ESCC) and precancerous lesion, in order to provide valuable clues for early diagnosis.

METHODS: Seventy-two specimens were collected, including dysplasia, in situ carcinoma, early ESCC, ESCC and lymph metastatic carcinoma. The expression of annexin I, Grp94, mutant p53 and ki-67 were detected using immunohistochemical staining (IHC).

RESULTS: Compared with the normal esophageal epithelia, the expressions of annexin I, Grp94, mutant p53 and ki-67 were abnormal in precancerous lesions. Loss of annexin I (68.3%), positive expression of p53 (67.6%) and ki-67 (71.1%) were observed in low grade lesions (P < 0.01), and Grp94 expression was increased significantly (62.0%) in early invasive cancer (P < 0.01).

CONCLUSION: Annexin I, mutant p53 and ki-67 may be the biomarkers of early ESCC, and Grp94 may be an important biomarker of progressive ESCC.

Down-regulation of γ-synuclein in human esophageal squamous cell carcinoma

AIM: To investigate gene expression pattern of human γ-synuclein gene in human esophageal squamous cell carcinoma (ESCC) by using semi-quantitive reverse transcription polymerase chain reaction (RT-PCR), and to study the role of γ-synuclein in the development of human ESCC.

METHODS: Semi-quantitive RT-PCR of 27 pairs of specimens of human ESCC tissues and corresponding normal tissues was used to investigate the expression pattern of γ-synuclein in ESCC. 9706/γ-syn cells in which γ-synuclein was overexpressed were obtained through cloning γ-synuclein gene by PCR and transfecting it into ESCC 9706 cells, then selecting with G-418 for 14 days. The biological effects of γ-synuclein were measured and compared between 9706/γ-syn and 9706/vec cells by cell growth curve and soft agar assay.

RESULTS: RT-PCR showed that γ-synuclein gene was expressed in all the 27 cases of normal epithelial tissues, while downregulation of γ-synuclein was observed in 16 out of the 27 cases (59.3%) of ESCC. There were also 6 cases of ESCC tissues with a high expression level of γ-synuclein mRNA. In functional analysis we found that over-expression of γ-synuclein in ESCC 9706 cells could inhibit the growth rate and transformation ability of ESCC 9706 cells.

CONCLUSION: The low expression level of γ-synuclein in human ESCC and the biological effects of γ-synuclein over-expression on ESCC 9706 cells suggest that γ-synuclein may play a role as a negative regulator in the development of human ESCC.

Cloning and sequence analysis of 5' fragment of Hoxa-11 gene in Latimeria chalumnae

Hoxa-11 gene is essential for the development of fish fins and tetrapod limbs. Based on the published nucleotide sequences of human and mouse Hoxa-11 genes, two degenerate primers were designed. Latimeria Hoxa-11 gene fragment was amplified by PCR, cloned and sequenced. The acquired Hox gene fragment, which encodes 204 amino acids, is comprised of 2,065 bp, including most exon 1, intron and partial exon 2. The homology of latimeria Hoxa-11 protein is 66.0% to human, 67.6% to mouse, 74.4% to chick, 72.8% to frog, and 59.7% to zebrafish, respectively. The exon 2 region including the homeobox and the splice site are highly conserved. However, the exon 1 region has increased in size by 16% from latimeria to human. Sequence analysis further revealed that exon 1 of latimeria Hoxa-11 could be divided into four regions: two highly conserved regions, a moderately conserved region, and a variable region adjacent to the intron. The size variation is primarily caused by the accumulation of alanine repeats and of flanking segments rich in glycine and serine in the variable region. It implies that the variable region might be related to acquisition of new functions in the fin-limb transition and vertebrate evolution. Besides the homeobox, two highly conserved regions in exon 1 and two phylogenetic footprints in the intro were found. The strong sequence conservation suggests an important functional role of these regions.

Photodynamic therapy-induced death of MCF-7 human breast cancer cells: a role for caspase-3 in the late steps of apoptosis but not for the critical lethal event

Photodynamic therapy (PDT) causes mitochondrial damage and induces apoptosis through release of cytochrome c and activation of caspase-3. To test whether caspase 3 is the sole executioner of apoptosis and its role in overall cell lethality, we compared the response of MCF-7c3 cells that express a stably transfected CASP-3 gene to that of parental MCF-7:SW8 cells transfected with vector alone (MCF-7v). Following photosensitization with the phthalocyanine Pc 4 and red light, cytochrome c was released from the mitochondria to equivalent extents in the two cell lines. However, the appearance of apoptotic indicators, such as active caspase-3 (DEVDase), cleavage of poly(ADP-ribose) polymerase, and oligonucleosomal DNA fragmentation, was observed only in MCF-7c3 cells during the first 6 h after photosensitization. Although production of 50-kb DNA fragments and chromatin condensation were found in PDT-treated MCF-7v cells by 20-24 h posttreatment, the rate and extent of apoptosis were much less than in MCF-7c3 cells. MCF-7c3 cells were more sensitive to photosensitization than were MCF-7v cells when assayed for loss of viability by reduction of a tetrazolium dye. However, the two cell lines were equally sensitive to photodynamic killing when evaluated by a clonogenic assay. These results show (a) the importance of assessing overall cell death by clonogenic assay; (b) that the critical lethal event is independent of caspase-3, perhaps at or near the release of cytochrome c from mitochondria; and (c) that the caspase-3-mediated events appear to be irrelevant in determining overall killing of cells.

Etk/Bmx, a PH-domain containing tyrosine kinase, protects prostate cancer cells from apoptosis induced by photodynamic therapy or thapsigargin

Prostate carcinoma (PCA) is the most frequently diagnosed malignancy in American men. PCA at advanced stages can both proliferate abnormally and resist apoptosis. Among the many known signal transduction pathways, phosphatidylinositide-3'OH kinase (PI3-kinase) has been shown to play an important role in cell survival and resistance to apoptosis. In this study, we investigate the involvement of Etk/Bmx, a newly discovered tyrosine kinase that is a substrate of PI3-kinase, in protection of prostate cancer cells from apoptosis. Parental LNCaP cells and two derivative cell lines, one overexpressing wild type Etk (Etkwt) and the other expressing a dominant negative Etk (EtkDN), were used to study the function of Etk. The cells were treated with photodynamic therapy (PDT), a newly approved cancer treatment which employs a photosensitizer and visible light to produce an oxidative stress in cells, often leading to apoptosis. Our results indicate that PDT induces apoptosis in LNCaP cells, as measured by DNA fragmentation and by cleavage of poly(ADP-ribose) polymerase (PARP), and moreover, the extent of apoptosis was much reduced in Etkwt cells as compared to LNCaP or EtkDN cells. Assay of overall cell viability confirmed that Etkwt cells were considerably less sensitive to PDT than were the parental LNCaP or EtkDN cells. Similar results were found in response to thapsigargin (TG). A specific inhibitor of PI3-kinase, LY294002, abolished Etk activity and markedly increased TG-induced PARP cleavage. The results suggest that Etk/Bmx is an efficient effector of PI3-kinase and that the newly described PI3-kinase/Etk pathway is involved in the protection of prostate carcinoma cells from apoptosis in response to PDT or TG.

Photodynamic therapy-induced apoptosis in lymphoma cells: translocation of cytochrome c causes inhibition of respiration as well as caspase activation

L5178Y-R mouse lymphoma (LY-R) cells undergo rapid apoptosis when treated with photodynamic therapy (PDT) sensitized with the silicon phthalocyanine Pc 4. In this study we show that cytochrome c is released into the cytosol within 10 min of an LD99.9 dose of PDT. Cellular respiration is inhibited by 42% at 15 min, and 60% at 30 min after PDT treatment, and caspase 3-like protease activity is elevated by 15 min post-PDT. In digitonin-permeabilized cells addition of cytochrome c to the respiration buffer reverses PDT-induced inhibition of state 3 respiration via Complex I by 40-60%, and via Complex III by 50-90%. In contrast, extramitochondrial cytochrome c does not stimulate respiration in permeabilized control cells, and catalyzes only a low rate of oxygen consumption via electron transfer to cytochrome b5 on the outer mitochondrial membrane. These results demonstrate that PDT-induced inhibition of respiration is primarily due to leakage of cytochrome c into the cytosol rather than to damage to the major enzyme complexes of the electron transport chain. Whether or not inhibition of respiration influences the time course or extent of Pc 4-PDT-induced apoptosis in LY-R cells is not clear at the present time.

Immunotherapy of human ovarian carcinoma with OvaRex MAb-B43.13 in a human-PBL-SCID/BG mouse model

The monoclonal antibody (MAb) B43.13, binding to the ovarian cancer-associated antigen CA125, has been injected into more than 200 patients with ovarian cancer to detect recurrence of the disease. The follow-up of the patients revealed surprisingly long survival spans for several patients despite high CA125 levels. To investigate the therapeutic effectiveness of OvaRex MAb-B43.13 (AltaRex, Edmonton, Canada) under well-controlled conditions, the antibody was tested in a human-PBL-SCID/BG mouse model with CA125 positive human ovarian cancer cells. Mice were reconstituted with human peripheral blood lymphocytes (PBL, normal donors) by intraperitoneal (IP) injection of 2 to 3 x 10(7) PBL/mouse. OvaRex MAb-B43.13 was administered at 100 microg/mouse in phosphate buffered saline (PBS), in three different experimental set-ups. An isotype-matched control antibody (MOPC21 or MAb-170) and PBS injection served as controls. The ovarian cancer cell line NIH:OVCAR-NU-3 was injected IP at 1 x 10(6) cells/mouse or subcutaneously (SC) at 4 x 10(6) cells/mouse. Human-PBL-SCID/BG mice were either immunized before injection of tumor cells, along with tumor cells or after small tumors were established (2 weeks after transplantation). Antibody injections were repeated twice in 2-week intervals. Functional and cellular characterization of serum and PBL from these mice demonstrated the successful engraftment of a human immune system in those mice. All three experiments showed that OvaRex MAb-B43.13 treatment could (a) delay or prevent development of tumors; (b) reduce the size of small established tumors (SC tumor injection) or suppress ascites formation; (c) delay tumor growth when injected prior to tumor implantation; and (d) prolong the survival of the mice (i.p. tumor injection).

Protease activation and cleavage of poly(ADP-ribose) polymerase: an integral part of apoptosis in response to photodynamic treatment

Apoptosis induced by numerous cancer chemotherapeutic and other toxic agents has been shown to proceed through a cascade of proteases, now termed caspases, culminating in cleavage of a set of proteins. The ability of photodynamic treatment (PDT) with the phthalocyanine Pc 4 to activate cellular caspases has been assessed during the rapid apoptosis in murine lymphoma L5178Y-R cells. Cells were exposed to combinations of Pc 4 and activating red light that result in > or =90% cell death, as judged by a clonogenic assay. The rate of entry of cells into apoptosis was dose dependent. For 0.5 microM Pc 4 and either 2.1 or 3 kJ/m2, which kill 90 or 99.9% of the cells, oligonucleosomal fragmentation was visible on agarose gels as early as 60 or 30 min after PDT, respectively. To assess caspase activation, cells were harvested at various times after PDT, and cell proteins were subjected to electrophoresis and Western blot analysis, using an antibody to poly(ADP-ribose) polymerase (PARP). The cleavage of the normally Mr 116,000 PARP into fragments of Mr approximately 90,000 was observed at approximately the same time as the earliest DNA fragmentation. An antibody to the polymer, poly(ADP-ribose), did not recognize the Mr approximately 90,000 PARP cleavage products, in contrast to the parent enzyme. This analysis also revealed that levels of a poly(ADP-ribosylated) Mr 100,000 protein, tentatively identified as topoisomerase I, were maintained in cells after PARP was fully cleaved. Caspase-3 (and/or caspase-7) activity, as measured in cell lysates with the fluorogenic substrate DEVD-AMC, was elevated almost immediately after PDT. The cell-permeable, irreversible caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp(O-methyl)-fluoro-methylketone, inhibited PDT-induced apoptosis and PARP cleavage, whereas the inactive peptide analogue, benzyloxycarbonyl-Phe-Ala-fluoromethyl ketone, was without effect. The results indicate that PDT-induced apoptosis is mediated by activation of caspase-3 and/or other similar caspases.

Rapid tyrosine phosphorylation of HS1 in the response of mouse lymphoma L5178Y-R cells to photodynamic treatment sensitized by the phthalocyanine Pc 4

The ability of photodynamic treatment (PDT) with the phthalocyanine Pc 4 to activate cellular signal transduction pathways in murine lymphoma L5178Y-R cells has been assessed by observing increases in protein tyrosine phosphorylation at early times post-PDT. Western blot analysis with an anti-phosphotyrosine antibody revealed a dramatic increase in phosphorylation of two major protein bands of Mr approximately 80,000 and approximately 55,000 in response to PDT. The increase was PDT dose-dependent, occurred as early as 20 s after initiation of light exposure of Pc 4-preloaded cells and was amplified by the presence of the protein tyrosine phosphatase inhibitor, sodium orthovanadate (NaVO4). By immunoprecipitation, one of the Mr approximately 80,000 phosphorylated proteins has been identified as HS1, a substrate of nonreceptor-type protein tyrosine kinases. Although vanadate greatly enhanced the level and extent of PDT-induced phosphorylation, it had no influence on overall photocytotoxicity or on the rate of apoptotic DNA fragmentation. Genistein, an inhibitor of protein tyrosine kinases, diminished tyrosine phosphorylation of the Mr approximately 80,000 and other proteins and dramatically potentiated cell killing induced by PDT but did not significantly affect PDT-induced apoptosis. The results suggest that PDT rapidly activates a membrane-associated src family kinase(s) in L5178Y-R cells, one substrate of which is HS1, and that protein tyrosine phosphorylation is part of a stress response, protecting a portion of the cells from the lethal effects of PDT but not altering the mechanism by which they die.

Role of transchelation in the uptake of 99mTc-MAb in liver and kidney

High radioactivity in liver and kidney after administration of 99mTc-labeled antibodies is a major detriment to the use of radiolabeled antibodies for diagnosis and therapy. In the present study, the uptake mechanism of radioactivity by liver and kidney involving 99mTc moiety was investigated. The data of in vitro and in vivo thiol transchelation studies, biodistribution alteration of 99mTc-MAb after specific modulation of endogenous thiol containing compounds, and the finding of 99mTc-labeled cysteine and GSH in bile, urine and kidney after administration of 99mTc-MAb demonstrated that transchelation by thiols (cysteine and GSH) played an important role in the localization of radiotracer from 99mTc MAb in normal tissues such as liver and kidney.

Studies on metabolism of directly labeled 99mTc-antibody in mice

The elucidation on the metabolic products of the 99mTc-antibody conjugates may provide insights and approaches that would reduce the undesirable deposition of radioactive species in normal tissues. In this investigation, the radiolabeled species in blood, urine, bile and extracts of liver and kidney obtained at different times after the injection of a model antibody, 99mTc-MAb170, into mice were analyzed with various chromatographic methods. Ninety-nine to 100% of the radioactivity in serum was associated with intact MAb170. The radioactivity in liver homogenate extract was strictly protein-bound to either intact MAb or low molecular weight species (LMW). In kidney extracts, the majority of the radioactivity was protein bound 99mTc, with less than 8% of the activity being non-protein bound 99mTc. Multiple 99mTc-containing protein and non-protein species were found in urine and bile. Evidence supporting the presence of 99mTc-cysteine and 99mTc-glutathione in bile, kidney and urine was also obtained. No evidence for the in vivo formation of 99mTc-pertechnetate in mouse blood, liver, kidney, bile and urine was observed.

The induction of partial resistance to photodynamic therapy by the protooncogene BCL-2

Photodynamic therapy (PDT) is an efficient inducer of apoptosis, an active form of cell death that can be inhibited by the BCL-2 oncoprotein. The ability of BCL-2 to modulate PDT-induced apoptosis and overall cell killing has been studied in a pair of Chinese hamster ovary cell lines that differ from one another by a transfected human BCL-2 gene in one of them (Bissonnette et al, Nature 359, 552-554, 1992). Cells were exposed to the phthalocyanine photosensitizer Pc 4 and various fluences of red light. Pc 4 uptake was identical in the two cell lines. The parental cells displayed a high incidence of apoptosis after PDT, whereas at each fluence there was a much lower incidence of apoptosis in the BCL-2-expressing cells. Apoptosis was monitored by (a) observation of 50 kbp and oligonucleosome-size DNA fragments by gel electrophoresis, (b) flow cytometry of cells labeled with fluorescently tagged dUTP by terminal deoxynucleotidyl transferase and (c) fluorescence microscopy of acridine orange-stained cells. The time course of apoptosis varied with the PDT dose, suggesting that only after moderately high doses (> 99% loss of clonogenicity) was there a relatively synchronous and rapid entry of many cells into apoptosis. At PDT doses reducing cell survival by 90 or 99%, significant increases in apoptotic cells were found in the population after 6-12 h. Clonogenic assays showed that BCL-2 protein inhibited not only apoptosis but overall cell killing as well, effecting a two-fold resistance at the 10% survival level. Thus, BCL-2-expressing cells may be relatively resistant to PDT.

Studies on the uptake mechanisms of 99mTc-labeled antibodies by liver tissue

In this study, the roles of various protein alterations on the uptake of 99mTc labeled antibodies by isolated hepatocytes and by selected tissues in vivo were explored. In vitro binding studies of radiolabeled antibodies with hepatocytes demonstrated that the uptake of the radiolabel was a function of incubation duration and dose dependent. The uptake of 99mTc-antibodies could be inhibited by excess unlabeled F(ab')2 and Fc fragments as well as intact antibody. Liver uptake could not be reduced by a large insert pretreatment dose of unlabeled or aggregated antibody. These observations indicated that both Fab and Fc portions on the antibody molecule as well as the intact antibody may play important roles in the uptake of the radiolabel by liver tissue.