Parotid CT imaging reporting and data system: A preliminary study / 北京大学学报(医学版)

OBJECTIVE@#To establish a Parotid Imaging Reporting and Data System (PI-RADS) for CT diagnosis of the parotid gland neoplasms and to investigate the clinical applicable value and feasibility of PI-RADS.@*METHODS@#Patients who had been diagnosed with primary parotid gland neoplasms and had received surgical treatments in Peking University School and Hospital of Stomatology during the period of January 2013 to December 2016 were included in this study. The diagnoses were confirmed by the postoperative pathological examinations in all the patients. The CT imaging data of all patients were retrospectively reviewed and analyzed by two readers in consensus. Imaging characteristics related to the parotid neoplasms were extracted and quantified. Based on comprehensive analysis of the imaging characteristics, the probabilities of the benign and malignant neoplasms were evaluated and classified into six grades, PI-RADS 1-6 (PI-RADS 1: normal parotid gland; PI-RADS 2: confidently benign lesions; PI-RADS 3: probably benign lesions without confirmed evidence of malignancy; PI-RADS 4: suspected malignancy without sufficient evidence of malignancy; PI-RADS 5: confidently malignant lesions; PI-RADS 6: lesions with confirmed pathological evidence of malignancy).@*RESULTS@#A total of 897 patients with 1 003 parotid lesions were included. The lesions included 905 benign and 98 malignant lesions. The proportions of the malignancies in PI-RADS 2, PI-RADS 3, PI-RADS 4 and PI-RADS 5 according to the two readers in consensus were 0.4%, 5.7%, 35.5% and 96.7% respectively. The overall Cohen's Kappa test showed medium consistency between the two independent researchers (κ=0.614, P<0.001, 95%CI: 0.569-0.695). Pearson Chi-square test showed that the proportions of malignancies increased with the diagnostic PI-RADS grades (Cochran-Armitage trend test, Z=-15.579, P<0.001). The results of Pearson Chi-square tests showed significant differences between the grades [PI-RADS 2 and 3 (χ²=12.048, P=0.001); PI-RADS 3 and 4 (χ²=75.231, P<0.001); PI-RADS 4 and 5 (χ²=32.266, P<0.001)].@*CONCLUSION@#PI-RADS can be used to evaluate the risk of malignancy and will be helpful to improve the imaging diagnosis and clinical treatment of parotid gland neoplasms.

BRAF gene mutations in ameloblastic fibromas / 北京大学学报(医学版)

OBJECTIVE@#To investigate the BRAF gene mutations in ameloblastic fibroma (AF), and to further analyze the relationship between the BRAF mutation and clinical characteristics so as to provide new reference to the study of AF's molecular pathology.@*METHODS@#Sixteen cases diagnosed as AF at the Department of Oral Pathology, Peking University School of Stomatology between January 1990 and December 2017 were collected. Genomic DNA was extracted from formalin-fixed, paraffin embedded tissues using the QIAamp DNA Mini Kit (Qiagen, Germany) according to the manufacturer's instructions. Polymerase chain reaction (PCR) and direct sequencings were used to detect the BRAF gene mutations. The clinicopathological data, such as the age, location of the lesion, symptoms and treatments were retrospectively analyzed.@*RESULTS@#The sixteen cases of AF involved nine women and seven men aged 2-67 years. Three lesions occurred in the maxilla and thirteen in the mandible. The most common presenting symptom of AF was a painless slowly enlarging mass with swelling. Ten patients received conservative treatment and the other six patients received radical surgery. Three cases relapsed during the study period. BRAF gene mutation was found in sixteen of all the sixteen samples analyzed (100%). The BRAF mutation was a point mutation with a thymine-adenine transversion at nucleotide 1 799 of 15 exons, resulting in a change at residue 600 that substituted glutamine for valine. This mutation was the strongest activator of the downstream RAS/RAF/MEK/ERK-MAPK signaling pathway. This helped to bring about a gain-of-function mutation due to a V600E substitution. Many studies identified that BRAF regulated survival, apoptosis, and proliferation of cells by inducing MAPK pathways activation. For the existing cases, none of the age, sex, location, recurrence and treatments had a statistically significant correlation with BRAF mutation.@*CONCLUSION@#Our findings demonstrated high prevalence of BRAF V600E mutation in AF. The pathogenic role remains to be clarified．.

Identification of the involvement of LOXL4 in generation of keratocystic odontogenic tumors by RNA-Seq analysis / 国际口腔科学杂志·英文版

Keratocystic odontogenic tumors (KCOT) are benign, locally aggressive intraosseous tumors of odontogenic origin. KCOT have a higher stromal microvessel density (MVD) than dentigerous cysts (DC) and normal oral mucosa. To identify genes in the stroma of KCOT involved in tumor development and progression, RNA sequencing (RNA-Seq) was performed using samples from KCOT and primary stromal fibroblasts isolated from gingival tissues. Seven candidate genes that possess a function potentially related to KCOT progression were selected and their expression levels were confirmed by quantitative PCR, immunohistochemistry and enzyme-linked immunosorbent assay. Expression of lysyl oxidase-like 4 (LOXL4), the only candidate gene that encodes a secreted protein, was enhanced at both the mRNA and protein levels in KCOT stromal tissues and primary KCOT stromal fibroblasts compared to control tissues and primary fibroblasts (P<0.05). In vitro, high expression of LOXL4 could enhance proliferation and migration of the human umbilical vein endothelial cells (HUVECs). There was a significant, positive correlation between LOXL4 protein expression and MVD in stroma of KCOT and control tissues (r=0.882). These data suggest that abnormal expression of LOXL4 of KCOT may enhance angiogenesis in KCOT, which may help to promote the locally aggressive biological behavior of KCOT.

Identification of a mutation in exon 4 of apolipoprotein E gene in a family affected with lipoprotein glomerulopathy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify potential mutation of apolipoprotein E (apoE) gene in a male patient affected with lipoprotein glomerulopathy (LPG), his mother and his sister.</p><p><b>METHODS</b>The patient and his mother both had histologically confirmed LPG. His sister and his father were asymptomatic. Genomic DNA was extracted from peripheral blood samples. PCR products of the coding region of exons 3 and 4 of the apoE gene were cloned into a pTA2 vector and sequenced. Genetic variations of the apoE gene were detected using PCR and restriction fragment length polymorphism (RFLP).</p><p><b>RESULTS</b>An apoE gene mutation was identified in the patient's family. Sequence analysis confirmed a 9-bp deletion in the exon 4 of apoE gene from nt 484 to 492. The 9-bp deletion resulted in loss of 3 amino acids at positions 143-145. The sister of the propositus carried the same mutation, though she had neither proteinuria nor elevated plasma apoE. Sequence analysis of exon 3 showed no abnormality. No abnormalities were found in the father's apoE gene sequence. Analysis of genetic variations of the apoE gene by PCR and RFLP confirmed a 57 bp fragment consistent with the 9-bp deletion in exon 4. The father had a normal ε 3 ε 3 genotype.</p><p><b>CONCLUSION</b>The 9 bp deletion of apoE may be associated with the pathogenesis of LPG.</p>

Identification of known and novel PTCH mutations in both syndromic and non-syndromic keratocystic odontogenic tumors / 国际口腔科学杂志·英文版

<p><b>AIM</b>To clarify the role of PTCH in patients with NBCCS-related and non-sydromic keratocystic odontogenic tumors.</p><p><b>METHODOLOGY</b>Mutation analysis was undertaken in 8 sporadic and 4 NBCCS-associated KCOTs.</p><p><b>RESULTS</b>Four novel and two known mutations were identified in 2 sporadic and 3 syndromic cases, two of which being germline mutations (c.2179delT, c.2824delC) and 4 somatic mutations (c.3162dupG, c.1362-1374dup, c.1012 C>T, c.403C>T).</p><p><b>CONCLUSION</b>Our findings suggest that defects of PTCH are associated with the pathogenesis of syndromic as well as a subset of non-syndromic KCOTs.</p>

Koumine-induced apoptosis of human colonic adenocarcinoma cells: the cell biological mechanism / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the cell biological mechanism of koumine-induced apoptosis of human colonic adenocarcinoma cells.</p><p><b>METHODS</b>The effects of LoVo cell koumine on the membrane potential, mitochondrial membrane potential, concentration of cytosolic free calcium, reactive oxygen species (ROS) and gap junctional intercellular communication was observed by laser scanning confocal microscopy.</p><p><b>RESULTS AND CONCLUSION</b>Koumine lowered the membrane potential and mitochondrial membrane potential of LoVo cells and decreased the concentration of free cytosolic calcium, which was increased to a level higher than the basal one after addition of EDTA. Koumine also increased the reactive oxygen species and enhanced the gap junctional intercellular communication of LoVo cells. These findings may explain the possible mechanisms of koumine-induced LoVo cell apoptosis.</p>

Functional changes of dendritic cells after infection by recombinant retrovirus carrying human telomerase reverse transcriptase gene fragment / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the functional changes of dendritic cells (DCs) after infection by recombinant retrovirus carrying human telomerase reverse transcriptase (hTERT) gene fragment.</p><p><b>METHODS</b>Interleukin-12 (IL-12) levels in DC culture supernatant was determined by enzyme-linked immunosorbent assay (ELISA). The abilities of DCs infected with recombinant retrovirus carrying hTERT gene (hTERT-DCs) and non-infected DCs (N-DCs) to stimulate allogeneic lymphocyte proliferation were evaluated with mixed leukocytes reaction (MLR), and the surface markers of DCs including CD80, CD83, CD86 and HLA-DR were detected by flow cytometry. Cytotoxic T lymphocyte (CTL) assay was performed with CytoTox 96 non-radioactive cytoxicity assay.</p><p><b>RESULTS</b>Compared with N-DCs, hTERT-DCs showed no significant changes in IL-12 secretion and capacity to stimulate allogeneic lymphocytes reaction, but had significantly lower CD83 expression. Specific CTLs induced by hTERT-DCs resulted in higher cytotoxicity against telomerase-positive target cells than that against the negative target cells.</p><p><b>CONCLUSION</b>Infection with the recombinant retrovirus carrying hTERT fragment may jeopardize the maturation of DCs, which, however, still retain their capacity to activate and stimulate lymphocyte proliferation and to prime autologous T lymphocytes to generate specific CTL against hTERT.</p>