MLL tandem duplication and multiple splicing in adult acute myeloid leukemia with normal karyotype.

Rearrangement of the MLL (myeloid-lymphoid or mixed-lineage leukemia) gene through a reciprocal chromosomal translocation is found in 5% of adult acute myeloid (AML) and 10% of pediatric acute lymphoid (ALL) leukemia. More than 25 different reciprocal chromosomal translocations, with an 11q23 breakpoint, fuse the MLL gene (also named ALL-1, HRX and Htrx1) to a second partner gene. These leukemias have poor prognosis and frequently have a monocytic, lymphoid or biphenotypic (myeloid and lymphoid) antigen expression in blast cells. Approximately 20-30% of patients diagnosed as having adult de novo, AML have normal chromosomes by metaphase analysis and the majority of these patients have good prognosis. With the use of reverse transcriptase-polymerase chain reaction (RT-PCR) technique and Southern blot analysis, we found that seven of 34 such patients (21%) had a tandem partial duplication of exons 2 to 6 or 2 to 8 of the MLL gene. These seven patients showed a median survival of 2.7 months, compared to a 6.8 months median survival for all other patients in the study. If confirmed on a large series of patients, our findings may help differentiate AML with normal karyotype and poor prognosis from those with normal karyotype and a more favorable prognosis.

Increased expression of cyclooxygenase-2 protein in human gastric carcinoma.

Gastric adenocarcinoma is one of the most common malignancies in the world, and yet little is known about its molecular process of development and progression. Recent studies have suggested that ingestion of nonsteroid anti-inflammatory drugs reduces the risk of colon cancer, presumably by inhibiting the cyclooxygenase (COX) enzyme. COX-2, one isoform of the COX enzyme, is the rate-limiting enzyme in prostaglandin synthesis, and the function of this enzyme is thought to relate to inflammatory processes and carcinogenesis. To understand the role of COX enzyme in gastric cancer, we measured COX-2 expression in 104 human gastric carcinoma tissues by immunohistochemical analysis. We obtained tissue specimens from 104 surgically resected gastric adenocarcinoma patients. We performed immunohistochemical stain for human COX-2 with polyclonal antibody in gastric carcinoma. After curative resection and extensive lymph node dissection, all patients received adjuvant chemotherapy containing 5-fluorouracil. Expression of COX-2 showed cytoplasmic staining, not only in cancer cells but also in precancerous lesions such as metaplastic and adenomatous cells. We confirmed up-regulation of COX-2 in gastric cancer tissues compared with normal paired mucosa using Western blot analysis. There was no correlation between clinicopathological characteristics of gastric cancer patients and intensity of COX-2 protein expression. This study indicates that COX-2 protein over-expression may contribute to an early event of gastric cancer development, and it further suggests that selective inhibition of COX-2 may provide a chemopreventive effect against gastric carcinogenesis.

Alternative RNA splicing of the MLL gene in normal and malignant cells.

The human MLL (mixed-lineage leukemia or myeloid-lymphoid leukemia) gene belongs to the trithorax gene family of which the Drosophila trithorax (trx) gene is known to regulate homeotic genes through alternative RNA splicing. To test if such a splicing mechanism also operates in MLL, we evaluated mRNA transcripts from a large number of normal and malignant human cells, making use of RT-PCR, PCR cloning, DNA sequencing and Northern blot analysis. Our findings indicate that different cell types transcribe MLL mRNA species lacking exons that generally encode putative regulatory domains such as AT hooks (exon 3), repression domain (exon 6), zinc finger motifs (exon 8) and activation domain (exon 18). Such findings suggest that posttranscriptional regulation by alternative RNA splicing may play an important role in MLL gene expression and provides the rationale for a mechanism by which this gene, with multiple functional domains, could produce discrete protein products that may prove critical in the regulation of human homeobox genes.

Vascular endothelial growth factor in the serum of patients with non-small cell lung cancer: correlation with platelet and leukocyte counts.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a potent angiogenic peptide expressed in a wide variety of tumors, and it stimulates angiogenesis and increases vascular permeability. Increased expression of VEGF may be associated with advanced stage and poor prognosis in patients with non-small cell lung cancer (NSCLC). METHODS: Using enzyme-linked immunosorbent assay, the levels of VEGF were determined in serum from 41 patients with untreated NSCLC (Stage: IIB, 3; IIIA, 6; IIIB, 17; IV, 15; HISTOLOGY: squamous cell carcinoma, 18; adenocarcinoma. 14; undetermined, 9). RESULTS: The median VEGF level was 312 pg/ml, ranging from 70 to 1440 pg/ml. Patients were divided into high VEGF (>312 pg/ml) and low VEGF (< or =312 pg/ml) groups using the median value as a cut-off. There were no significant associations between the serum VEGF levels and various clinicopathologic characteristics including age, gender, histologic type, stage and treatment. A significant positive correlation was found between serum VEGF levels and platelet counts (r=0.495; P=0.001). In addition, serum VEGF levels also correlated with leukocyte counts (r=0.478; P=0.002). In seven patients with measurement of follow-up serum VEGF levels at the end of treatment (chemotherapy and/or radiotherapy), the median serum VEGF level significantly decreased after the treatment (416 pg/ml; range, 96-812 pg/ml vs. 185 pg/ml; range, 49-487 pg/ml; P=0.028). However, the median platelet count (317,000/microl; range, 190,000-395,000/microl vs. 246,000/microl; range, 72,000-271,000/microl; P=0.028) and leukocyte count (10,000/microl; range, 8700-17,200/microl vs. 5100/microl; range, 3900-9500/microl; P=0.018) also decreased after the treatment. There was no statistically significant difference in the median survival of the patients between high VEGF group and low VEGF group (8 months vs. 9 months, P=0.647). CONCLUSIONS: Although serum VEGF level was significantly associated with platelet and leukocyte counts in NSCLC patients, it did not correlate with tumor burden and prognosis of the patients.

Surgical intervention in patients with aplastic anemia.

Eighteen surgical procedures have been performed on 14 cases of aplastic anemia (AA). Of the 10 major surgical procedures, 7 were emergency and 3 elective. The median duration from the diagnosis of AA to major surgery was 0.5 months (3 days-47.3 months), and the median survival after surgery was 12.3 months (4 days-38 months). The hematological status of AA at the time of major surgery were 3 in partial response (PR), 2 with no response (NR) and 5 at diagnosis, respectively; and those after major surgery were 2 with complete response (CR), 2 in PR, 1 with minimal response, and 2 in NR. Three postoperative complications were sepsis, pneumonia and atelectasis encountered in 2 cases. A total of 3 deaths were caused by infection and cancers. Considering the fact that surgery may not only control complications, but offer the opportunity to give effective therapy for AA and therefore improves chances for survival, it is strongly suggested that active surgical intervention should be performed if the patient's status is not terminal.

Detection of transforming growth factor-alpha in the serum of gastric carcinoma patients.

Transforming growth factor-alpha (TGF-alpha) is a ligand for epidermal growth factor receptor (EGFR) and it is overexpressed in various malignancies including lung, esophageal, colorectal, ovarian and gastric carcinomas. In patients with gastric carcinoma, its overexpression may be associated with advanced stage or poor prognosis. We have recently demonstrated that the mean serum level for EGFR in gastric carcinoma patients was significantly elevated compared with that of healthy controls. Using the enzyme-linked immunosorbent assay, the levels of TGF-alpha were determined in serum from 40 patients with gastric carcinoma (5 patients with stage I, 2 stage II, 4 stage III, and 29 stage IV patients) and 33 healthy controls. The mean serum level for TGF-alpha in the gastric carcinoma patients was significantly elevated as compared with that of healthy controls (104 +/- 235 vs. 22 +/- 16 pg/ml; p = 0.03). Eleven patients with gastric carcinoma (27.5%) showed elevated serum TGF-alpha levels above the cutoff value of 54 pg/ml (defined as 2 standard deviations above the mean of the control group). No significant association was noted between the positivity of TGF-alpha and clinicopathologic characteristics including gender, age and stage. However, poorly differentiated adenocarcinoma showed a higher positivity of serum TGF-alpha (43.8%) compared with other histologic types, which was marginally significant (p = 0.06). These results suggest that serum TGF-alpha could be useful as a tumor marker of gastric carcinoma for predicting prognosis and follow-up after surgery in patients whose initial serum TGF-alpha levels are elevated.

Endoscopic injection sclerotherapy in patients with bleeding esophageal varices: a retrospective analysis.

Endoscopic injection sclerotherapy has been accepted as the procedure of choice for patients with variceal hemorrhage. To evaluate the efficiency of endoscopic injection sclerotherapy in patients with bleeding esophageal varices, we did a retrospective study of 52 patients (non-sclerotherapy group) with bleeding esophageal varices who were admitted to hospitals and did not receive sclerotherapy and of 50 patients (sclerotherapy group) who received sclerotherapy with ethanolamine oleate. The mortality (sclerotherapy group vs. non-sclerotherapy group: 18.0% vs. 32.7%) during index hospitalization, the bleeding risk factor (the number of rebleeds per patient/month; 1.56 +/- 2.76 vs. 4.96 +/- 9.99: mean +/- SEM) and the mortality due to bleeding (14.0% vs. 36.5%) were higher in the non-sclerotherapy group than in the sclerotherapy group. Only those in Child's class C who received sclerotherapy had a significantly better survival rate than the non-sclerotherapy group (p less than 0.05). Although formal comparisons were not made because of the retrospective nature of this study, endoscopic injection sclerotherapy is effective and appears to be superior to conventional medical treatments.

Expression of thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection.

We evaluated the expression of thymidylate synthase (TS) in locally advanced gastric cancer patients treated with adjuvant chemotherapy after curative resection and investigated the association between TS expression and clinicopathologic characteristics including prognosis of the patients. TS expression was evaluated by immunohistochemical staining using TS106 monoclonal antibody in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil (5-FU) and doxorubicin-based adjuvant chemotherapy after curative resection. 65 patients (63%) had primary tumours with high TS expression (> or = 25% of tumour cells positive), and 38 patients (37%) demonstrated low TS expression (< 25% of tumour cells positive or no staining). High TS expression was associated with male gender (P = 0.002), poorly differentiated histology (P = 0.015), and mixed type in Lauren's classification (P = 0.027). There were no statistically significant differences in 4-year disease-free survival (60.0% vs. 57.2%, P = 0.548) and overall survival (59.6% vs. 59.3%, P = 0.792) between high-TS group and low-TS group. In conclusion, although high TS expression was associated with poorly differentiated histology and mixed type in Lauren's classification, it did not predict poor disease-free and overall survival in gastric cancer patients treated with 5-FU and doxorubicin-based adjuvant chemotherapy after curative resection. Further prospective studies including the evaluation of other biological markers associated with the resistance to 5-FU and doxorubicin are necessary.