Concordant point mutation of ETS-related gene (ERG) in tumor tissues from a synchronous multiple primary lung cancer: A case report / 北京大学学报(医学版)

The rearrangement of the gene encoding the transcription factor ETS-related gene (ERG) is thought to play a key role in the development of prostate cancer. However, the studies on the ERG mutations have been rarely reported in non-small cell lung carcinoma (NSCLC). Here, we reported genetic features regarding a case of a 68-year-old male patient who presented the primary synchronous multiple tumor lesions in the separated lungs. The patient was hospitalized due to the presence of tumor lesions at the right and left lungs revealed by a chest computerized tomography (CT) scan. After conducting lobectomies at the both lungs, the tumor nodules were all removed, and the histological analysis suggested adenocarcinoma at the both tumor lesions. The patient was diagnosed with synchronous multiple primary lung cancer (SMPLC) based on Martini-Melamed criteria and American College of Chest Physicians practice guidelines. An exome analysis of 315 genes in the two tumor lesions and a non-tumor lesion was conducted by using Illumina Nextseq500 platform from each tumor region to decipher a potential evolutional progress of SMPLC. Single or pair-end reads were first mapped to a human genome reference and filtered based on the mapping quality score. The read depth was ≥ 1 000× and the depth of coverage was 95%. The data revealed a discordant epidermal growth factor receptor (EGFR) from the separate lungs; additionally, a high frequency of point mutation on exon 9 H310P of the ERG gene was detected at the both sites of the tumor lesions. This case showed that a potential role of the molecular features analysis from each tumor lesion might contribute to the understanding of the evolutional development of SMPLC. This study suggests that the same environment may contribute certain gene(s) mutations in the same sites in the early stages of polyclonal tumor origins; meanwhile the extensive studies on these genes may help us understand the evolution and progress of tumor clones.

Prevalence and clinical application of TMPRSS2-ERG fusion in Asian prostate cancer patients: a large-sample study in Chinese people and a systematic review / 亚洲男科学杂志(英文版)

Fusion between the transmembrane protease serine 2 and v-ets erythroblastosis virus E26 oncogene homolog (TMPRSS2-ERG fusion) is a common genetic alteration in prostate cancer among Western populations and has been suggested as playing a role in tumorigenesis and progression of prostate cancer. However, the prevalence of TMPRSS2-ERG fusion differs among different ethnic groups, and contradictory results have been reported in Asian patients. We aim to evaluate the prevalence and significance of TMPRSS2-ERG fusion as a molecular subtyping and prognosis indicator of prostate cancer in Asians. We identified the fusion status in 669 samples from prostate biopsy and radical prostatectomy by fluorescence in situ hybridization and/or immunohistochemistry in China. We examined the association of TMPRSS2-ERG fusion with clinicopathological characteristics and biochemical recurrence by Chi-square test and Kaplan-Meier analysis. Finally, a systematic review was performed to investigate the positive rate of the fusion in Asian prostate cancer patients. McNemar's test was employed to compare the positive rates of TMPRSS2-ERG fusion detected using different methods. The positive rates of TMPRSS2-ERG fusion were 16% in our samples and 27% in Asian patients. In our samples, 9.4% and 19.3% of cases were recognized as fusion positive by fluorescence in situ hybridization and immunohistochemistry, respectively. No significant association between the fusion and clinical parameters was observed. TMPRSS2-ERG fusion is not a frequent genomic alteration among Asian prostate cancer patients and has limited significance in clinical practices in China. Besides ethnic difference, detection methods potentially influence the results showing a positive rate of TMPRSS2-ERG fusion.

Prevalence of ERG expression and PTEN loss in a Brazilian prostate cancer cohort

PTEN is the most commonly inactivated tumor suppressor gene in primary prostate cancer (PCa) and its loss is associated with poor clinical outcomes. ERG rearrangement is a genomic alteration frequently found in PCa and its prognostic significance has yielded mixed results. Although the association of PTEN and ERG biomarkers has potential impact on clinical outcomes, studies examining the two genes simultaneously are scarce in Brazilian populations. In this study, we retrospectively examined the relationship between ERG expression and PTEN loss in 119 surgically treated prostate cancer patients from Northeastern Brazil through immunohistochemical analysis. ERG expression was found in 41.0% (48/117) of cases and the loss of PTEN detected in 38.1% (40/105) of samples. ERG-positive cases were significantly associated with lower prostate weight; ERG negatively correlated with Gleason score above 6. The lack of associations for PTEN loss alone in this cohort is counter to the literature, which shows that PTEN loss is usually associated with more aggressive disease. The overlapping of the two biomarkers revealed that samples with positive ERG expression without PTEN loss were associated with lower Gleason and lower Grade group. This study contributes with the discussion about the development of the molecular profiling of prostate cancer. The further development of similar studies could help in stratifying specific risk groups, leading to a more personalized therapeutic decision for prostate cancer treatment.

Prognostic significance of mutually exclusive expression of ERG and SPINK1 in endocrine-treated prostatic cancer / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the expression and prognostic significance of ERG and SPINK1 expression in endocrine-treated prostatic cancer.</p><p><b>METHODS</b>Prostatic needle biopsies from 118 prostatic cancer patients primarily treated with endocrine therapy were reviewed. Immunohistochemical study for ERG and SPINK1 protein was carried out.</p><p><b>RESULTS</b>Co-expression of ERG and SPINK1 was not observed. The frequency of ERG protein expression in the 118 biopsies studied was 9.3% (11/118). The positive expression correlated with T stage (P=0.04) but not with patient age at diagnosis, prostatic specific antigen level, Gleason's score, M stage, tumor area and progression-free survival. Positive expression of SPINK1 was demonstrated in 11.0% (13/118) of the biopsies. SPINK1-positive cases carried a significantly shorter progression-free survival, as compared with SPINK1-negative cases (P=0.022). The expression was not associated with any other clinicopathologic variables. The following expression pattern showed statistically significant correlation with the clinical progress (P=0.029): ERG+/SPINK1- (11/118, 9.3%), ERG-/SPINK1+ (13/118, 11.0%) and ERG-/SPINK1- (94/118, 79.7%).</p><p><b>CONCLUSIONS</b>ERG and SPINK1 proteins are mutually exclusive.SPINK1 expression is associated with more aggressive clinical behavior and can serve as a prognostic biomarker in prostatic cancer.</p>

Mutation analysis of potassium channel genes KCNQ1 and KCNH2 in patients with long QT syndrome / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To determine mutations of two common potassium channel subunit genes KCNQ1, KCNH2 causing long QT syndrome (LQTS) in the Chinese.</p><p><b>METHODS</b>Thirty-one Chinese LQTS pedigrees were characterized for mutations in the two LQTS genes, KCNQ1 and KCNH2, by sequencing.</p><p><b>RESULTS</b>Two novel KCNQ1 mutations, S277L in the S5 domain and G306V in the channel pore, and two novel KCNH2 mutations, L413P in the transmembrane domain S1 and L559H in the transmembrane domain S5 were identified. The triggering factors for cardiac events developed in these mutation carriers included physical exercise and excitation. Mutation L413P in KCNH2 was associated with the notched T wave on ECGs. Mutation L559H in KCNH2 was associated with the typical bifid T wave on ECGs. Mutation S277L in KCNQ1 was associated with a high-amplitude T wave and G306V was associated with a low-amplitude T wave. Two likely polymorphisms, IVS11 + 18C > T in KCNQ1 and L520V in KCNH2 were also identified in two LQTS patients.</p><p><b>CONCLUSIONS</b>The mutation rates for both KCNQ1 (6.4%) and KCNH2 (6.4%) are lower in the Chinese population than those from North America or Europe.</p>

Protein kinase A-mediated phosphorylation of HERG potassium channels in a human cell line / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the molecular mechanism of human ether-a-go-go-related gene (HERG) potassium channels regulated by protein kinase A (PKA) in a human cell line.</p><p><b>METHODS</b>HERG channels were stably expressed in human embryonic kidney (HEK) 293 cells, and currents were measured with the patch clamp technique. The direct phosphorylation of HERG channel proteins expressed heterologously in Xenopus laevis oocytes was examined by (32)P labeling and immunoprecipitation with an anti-HERG antibody.</p><p><b>RESULTS</b>Elevation of the intracellular cAMP-concentration by incubation with the adenylate cyclase activator, forskolin (10 micromol/L), and the broad range phosphodiesterase inhibitor, IBMX (100 micromol/L), caused a HERG tail current reduction of 83.2%. In addition, direct application of the membrane permeable cAMP analog, 8-Br-cAMP (500 micromol/L), reduced the tail current amplitude by 29.3%. Intracellular application of the catalytic subunit of protein kinase A (200 U/ml) led to a tail current decrease by 56.9% and shifted the activation curve by 15.4 mV towards more positive potentials. HERG WT proteins showed two phosphorylated bands, an upper band with a molecular mass of approximately 155 kDa and a lower band with a molecular mass of approximately 135 kDa, indicating that both the core- and the fully glycosylated forms of the protein were phosphorylated.</p><p><b>CONCLUSIONS</b>PKA-mediated phosphorylation of HERG channels causes current reduction in a human cell line. The coupling between the repolarizing cardiac HERG potassium current and the protein kinase A system could contribute to arrhythmogenesis under pathophysiological conditions.</p>