Construction of CTC-ALK gene fusion detection system based on the multi-site magnetic separation in lung cancer and its clinical verification

Detected in a variety of solid tumors, including lung cancer, the EML4-ALK fusion gene plays an important role in promoting the occurrence and development of cancer. The existing detection methods for EML4-ALK fusion gene are all targeted at surgical or post-sampling tumor tissues, which cannot achieve early detection and real-time monitoring; therefore, a minimally invasive ALK gene fusion detection system is explored and constructed. Vimentin, EpCAM, and EGFR antibodies were grafted, respectively, to prepare multi-site immunoliposome magnetic beads, so as to capture CTC in blood for RT-PCR detection, and then the feasibility of this method was verified by detecting the positive rate of the EML4-ALK fusion gene and clinical information in combination with WB and IHC. The prepared multi-site immunoliposome magnetic beads showed high specificity and stability, and the average proliferation rate and capture rate of cells were 95% and 85%, respectively. In clinical blood samples, the CTC level of the grade I (G1) patients before the operation was lower than grade 2 (G2), and that of grade II (G2) was significantly lower than grade III (G3), but the difference was not significant after the operation. The RT-PCR results of CTC and the RT-PCR, WB, and IHC results of tissues were highly consistent in the fusion gene detection, and the positive rate of ALK gene fusion in 60 lung cancer patients was 31.67% and 28.33% before and after the operation, mostly EML4-ALK (V3) gene fusion. The CTC-ALK gene fusion detection system constructed successfully could avoid the problem of difficult sampling and post-sampling complications, and truly achieve the minimally invasive biopsy, so it was of important clinical significance for the diagnosis and efficacy evaluation of lung.

[Clinical utility of real-time fluorescent PCR for combined detection of anaplastic lymphoma kinase and c-ros oncogene 1 receptor tyrosine kinase in non-small cell lung cancer]

Objective: To investigate the clinical application value of combined detection of ALK fusion gene and c-ros oncogene 1 receptor tyrosine kinase (ROS1) fusion gene in non-small cell lung cancer (NSCLC) using real-time fluorescent PCR. Methods: A kit for combined detection of ALK fusion gene and ROS1 fusion gene based on fluorescent PCR was used to simultaneously detect the two fusion genes in 302 cases of NSCLC specimens. The results were validated through Sanger sequencing. The consistency of the two detection methods was analyzed. Results: All 302 cases of NSCLC specimens were successfully analyzed through fluorescent PCR (302/302). 12 cases (4.0%) were found to contain ALK fusion gene, including 3 cases with ALK-M1, 3 with ALK-M2, 3 with ALK-M3, 1 with ALK-M4, and 2 with ALK-M6 fusion gene.12 cases (4.0%) were found to contain ROS1 fusion gene, including 1 case with ROS1-M7, 8 cases with ROS1-M8, 1 case with ROS1-M12, 1 case with ROS1-M14, and 1 case with double-positive ROS1-M3 and ROS1-M8 fusion genes. The total detection rate of ALK fusion gene and ROS1 fusion gene was 7.9% (24/302) and 278 cases showed to be negative for ALK fusion gene and ROS1 fusion gene. The successful detection rates for Sanger DNA sequencing were also 100%. The positive, negative and total coincidence rates obtained by real-time fluorescent PCR and by Sanger DNA sequencing were all 100%. Conclusions: The results of Sanger DNA sequencing demonstrate that the real-time fluorescent PCR assay is equally effective in detecting ALK and ROS1 fusion genes in NSCLC tissues. Furthermore, real-time fluorescent PCR assay can be used to detect trace ALK and ROS1 fusion gene simultaneously in tiny samples, and can save time and avoid repeated sampling. It is worthy of recommendation as a rapid and reliable detection technique.

[Endometrial polyps. A clinico-pathologic analysis]

A clinico-pathologic analysis of 92 cases of endometrial polyps was carried out and the endometrium adjacent to the polyps was studied in 69 cases. Most endometrial polyps occurred between 30-60 years of age, often accompanied by abnormal uterine bleeding. Immature endometrial polyp was the most common pathologic type (65.0%), usually associated to some extent with hyperplastic changes. Cystic glandular hyperplasia was observed in nearly half of the polyps obtained from postmenopausal patients. Different histologic pictures were found in the adjacent endometrial tissues, of which 59.4% showed normal changes.