RT-PCR detection of tyrosinase, gp100, MART1/Melan-A, and TRP-2 gene transcripts in peripheral blood of melanoma patients

AIM

To detect the expression of genes encoding tyrosinase, gp100, MART-1/Melan A, and tyrosinase-related protein-2 (TRP-2) in peripheral blood of melanoma patients by reverse transcription-polymerase chain reaction (RT-PCR).

METHODS

Nineteen peripheral blood samples were obtained from 17 melanoma patients. When tested, 15 of them presented with clinically detectable metastatic disease. Samples of peripheral blood (7 mL) were collected from each patient into vacutainer cell preparation tubes. Mononuclear cells were isolated, total cellular RNA extracted, and then used as a template for reverse transcription to complementary DNA (cDNA). The cDNA was thereafter assayed by PCR for the expression of melanocyte-associated transcripts of tyrosinase, gp100, MART1/Melan-A, and TRP-2 genes.

RESULTS

Gp100 gene expression was detected in 13 out of 19 samples. In 4 of them, TRP-2 gene expression was also detectable. Expression of tyrosinase and Melan-A/MART-1 genes could not be observed. Interestingly, gp100 and TRP-2 gene transcripts were detected in patients having recurrent and/or metastatic disease at the time of testing.

CONCLUSION

The results we obtained support the use of RT-PCR assay for indirect detection of melanoma cells in peripheral blood of melanoma patients. As the transcripts for the tyrosinase gene and MART-1/Melan A gene were not detected, additional optimization experiments of RT-PCR assay are required.

[Radiotherapy of lung cancer]

The paper is aimed at approaching radiation therapy methods to physicians of other specialties and pointing to the potential of radiation therapy in the management of lung cancer patients. With the reference to its incidence and mortality rates, lung cancer ranks among the most frequent human malignant tumors. Therapy procedures for lung cancer depend upon tumor histology type, stage of disease and patient general condition. The said parameters therefore determine the application of surgery, radiation therapy and/or chemotherapy. In general, treatment results are usually rather poor, primarily due to lung cancer being the most frequently detected only as locally advanced or metastatic disease. Alike surgery, radiotherapy is a local form of treatment aimed at achieving local tumor control. This curative or palliative form of treatment is either applied alone or in combination with other treatment modalities. Irradiation is usually delivered by high energy photon beams from a telecobalt device or linear accelerator. The success of radiation therapy complies with the irradiation dose managed to be applied to tumor or tumor bed, which depends on patients general condition and site, size and spread of tumor. Radiotherapy with curative intent is applied in stage I, II and III non-small cell lung cancer patients with surgery being primarily applied in those with stage I and II. The efficacy of surgical treatment is to be improved by a combined-modality treatment. In stage III patients, who are more frequent than others, radical radiotherapy alone or in combination with chemotherapy is applied. Results of clinical trials report patients of relatively good general condition benefiting from combined-modality therapy. Palliative radiotherapy is to be applied in patients with stage IV non-small cell lung cancer. On the other hand, in patients with small cell lung cancer chemotherapy is the primary modality treatment. When the disease is limited to the lungs, the aim of radiotherapy is to optimize local control of the primary tumor.

The comparison of isodose plans: radiotherapy techniques in the treatment of thyroid ophtalmopathy

Thyroid ophthalmopathy is listed among benign disorders as the fourth indication for radiotherapy. Radiation reduces symptoms and signs of the disease in 46-93% of patients. Except for the lenses, the orbital content is resistant to the usual radiation dose of 20 Gy in 10 fractions. A number of radiotherapeutic techniques which avoid the lenses have been suggested. The testing of different techniques was performed on the same patient by using a computerized simulation of lateral alternating and crossed photon beams from a 6 MV and 18 MV linear accelerator or cobalt device. The radiation from a 6 MV linear accelerator using lateral beams angled at 5 degrees posteriori gave the best results. By this technique both lenses receive below 10% of the prescribed dose with a safety zone of 20% of the field size. Isodose distribution in clinical target volume is within the range of 10%. The described technique is recommended as it enables a successful avoidance of both lenses with a satisfactory homogeneity of dose distribution in the clinical target volume.

[Comparative study of the effectiveness of thermocoagulation, sclerotherapy and a combination of sclerotherapy and thermocoagulation in the treatment of acute peptic ulcer hemorrhage]

During the 3 years of the trial (June, 1988--December, 1990), 128 patients underwent urgent diagnostic endoscopy and hemostasis for acute peptic-ulcer bleeding. In the first group consisting of 57 patients, hemostasis was carried out by thermocoagulation (heat probe), in the second one (54 patients) by injection sclerotherapy and in the third group, hemorrhage was controlled by a combination of heater probe and sclerotherapy. The first and second groups did not differ significantly in age, sex, hemoglobin values, size, location of an ulcer, and kind of bleeding lesions classified according to Forrest. The efficacy of thermocoagulation and injection sclerotherapy in the treatment of acute peptic-ulcer bleeding was compared. In the group of patients treated with the heater probe, the initial hemostasis was achieved in 56 (98%) patients, while rebleeding occurred in 6 (10.7%) patients. In the sclerotherapy group, the initial hemostasis was accomplished in 51 (94.4%) patients, while 8 (15.6%) patients experienced rebleeding. There was no statistically significant difference in ultimate hemostasis between the patients treated with heater probe (94.7%) and the sclerotherapy patients (88.8%). The incipient results of the treatment of bleeding peptic ulcers obtained by a combination of sclerotherapy and heater probe were extremely good, but the final conclusion will be brought after the research on a larger group of patients. The only patient that died during the treatment belonged to the sclerotherapy group.