METTL27 is a prognostic biomarker of colon cancer and associated with immune invasion / 南方医科大学学报

OBJECTIVE@#To investigate the expression and gene function of methyltransferase-like protein 27 (METTL27) in colon cancer, its association with immune infiltration and its prognostic significance.@*METHODS@#We analyzed the expression levels of METTL27 in 33 cancers using R language and identified METTL27 as a differential gene in colon cancer. The related signaling pathways of METTL27 were analyzed by gene functional annotation and enrichment. SsGSEA algorithm was used to analyze immune infiltration, and logistic analysis was used to evaluate the correlation between METTL27 expression and clinicopathological features of the patients. Kaplan-meier analysis, univariate and multivariate Cox regression analysis were performed to construct a nomogram for evaluating the correlation between METTL27 expression and clinical prognosis. The expression level of METTL27 was further verified in colorectal cancer cell lines and 16 clinical specimens of colorectal cancer tissues using qPCR and Western blotting.@*RESULTS@#METTL27 was highly expressed in 21 cancers, and its expression was significantly higher in colon cancer than in adjacent tissues (P < 0.001). METTL27-related genes were identified by differential analysis, and functional annotation revealed that METTL27 was significantly enriched in transmembrane transport and lipid metabolism, and 5 related signaling pathways were identified by GSEA. METTL27 expression was negatively correlated with different T helper cells and central memory T cells (P < 0.001). The patients with a high METTL27 mRNA expression had a poor survival outcome. Cox regression analysis showed that METTL27 expression was an independent prognostic factor of the overall survival. The expression level of METTL27 was significantly higher in the colorectal cancer cell line than in normal cells (P < 0.05).@*CONCLUSION@#METTL27 is overexpressed in colon cancer and is associated with a poor prognosis of the patients. A high expression of METTL27 showed is associated less T cell immune infiltration, suggesting the potential of METTL27 as a prognostic marker of colon cancer.

Clinical significance of CRKL protein phosphorylation level in the treatment of chronic myeloid leukemia with imatinib / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the adaptor protein CRKL phosphorylation level (p-CRKL) and its significance in chronic myeloid leukemia (CML) treated with imatinib.</p><p><b>METHODS</b>ABL kinase domain was amplified by nested RT-PCR, domain point mutations analysis by direct sequencing, BCR-ABL mRNA level by real time-PCR, and p-CRKL level by flow cytometry in 52 bone marrow samples from 35 CML patients, and the relationship of p-CRKL level with ABL kinase domain mutation and with BCR-ABL mRNA level was analyzed.</p><p><b>RESULTS</b>In the 15 imatinib-resistant patients, ABL domain point mutations were detected in 6 with 4 types of nucleotide substitutions: T315I (n = 3), Y253H (n = 1), E255K and F317L. The incidence of mutations in disease chronic phase (CP), accelerated phase (AP) and blast phase (BP) was 25.00%, 40.00% and 30.00%, respectively. The BCR-ABL mRNA level in newly diagnosed CML was higher than that in imatinib-responded patients (P = 0.01); and so did in imatinib-resistant patients than in imatinib-effective patients (P = 0.03). The level of BCR-ABL mRNA was not significantly different between newly diagnosed CML and imatinib-resistant patients. p-CRKL%, MFI showed a high degree of phosphorylation in newly diagnosed CML and imatinib-resistant patients (P = 5.130; P = 3.178). The level of p-CRKL % and MFI in newly diagnosed group was higher than that in imatinib responded group (P = 0.000; P = 0.01) and also higher in imatinib-effective group than in imatinib-resistant group (P = 0.000; P = 0.02). There was a positive correlation between the level of BCR-ABL expression and p-CRKL% (and the MFI of p-CRKL) (P < 0.05).</p><p><b>CONCLUSION</b>It seems that p-CRKL detection might be helpful in predicting imatinib treatment outcomes.</p>

Expression of DNA-dependent protein kinase catalytic subunit in adult acute leukemia and its significance / 中国实验血液学杂志

This study was aimed to explore the expression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) in adult acute leukemia and its correlation with clinical characteristics, karyotype and prognosis. Indirect immunofluorescent cytometry was used to detect the expression of DNA-PKcs in bone marrow mononuclear cells of 105 patients with acute leukemia before chemotherapy and 41 of them after 2 cycles of chemotherapy. Cytogenetic data were obtained from 26 of them by R band karyotypic analysis. The results showed that the expression of DNA-PKcs was correlated with higher WBC count level in peripheral blood (p < 0.05), but was not obviously associated with median age, gender, percentage of bone marrow blasts, clinical classification, median hemoglobin level and median platelet count (p > 0.05). The middle and strong positive expression of DNA-Pkcs in non-remission group was significantly higher than that in remission group (p < 0.05). The positive rate of DNA-PKcs in abnormal chromosome group was significantly higher than that in chromosome normal group (p < 0.05). It is concluded that the DNA-PKcs expression level is closely related with the increased WBC count, and the expression of DNA-PKcs is correlated also with karyotype and clinical prognosis in adult acute leukemia.

Detection of ABL kinase domain point mutations in chronic myeloid leukemia patients receiving imatinib treatment / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the frequency and clinical significance of ABL tyrosine kinase point mutations in chronic myeloid leukemia (CML) patients receiving imatinib treatment.</p><p><b>METHODS</b>Nested reverse transcriptase-polymerase chain reaction (RT-PCR) was performed on 40 bone marrow samples from 23 patients to amplify the ABL kinase domain, followed by direct sequencing and sequence homologous analysis.</p><p><b>RESULTS</b>In the 23 patients analyzed, the ABL domain point mutations was detected in 7 patients who presented with 5 types of nucleotide changes, namely T315I(n=3), Y253H, E255K, F317L and G321W. The incidence of mutations in chronic phase (CP), accelerated phase (AP) and blast phase (BP) was 25.00%, 40.00% and 30.00%, respectively. For 6 of the 7 patients with mutations who were resistant to imatinib before sequencing, the daily drug dose had been increased to 600-800 mg daily for poor response to 400 mg/day imatinib. During the follow-up for 3-6 months, only the patient with F317L achieved major cytogenetic response (MCR), and the patient with Y253H and 1 of the 3 with T315I progressed to BP. The newly diagnosed patient with G321W IN cp achieved a complete hematologic remission and had a significant decrease of the proportion of BCR-ABL-positive cells.</p><p><b>CONCLUSIONS</b>ABL kinase point mutation is an important mechanism of imatinib resistance. The type of mutations is associated with the level of resistance to imatinib, and detection of ABL kinase point mutations by direct sequencing may help estimate the prognosis and plan for therapeutic strategy adjustment.</p>