An inducible long noncoding RNA, LncZFHX2, facilitates DNA repair to mediate osteoarthritis pathology.

Cartilage homeostasis is essential for chondrocytes to maintain proper phenotype and metabolism. Because adult articular cartilage is avascular, chondrocytes must survive in low oxygen conditions, and changing oxygen tension can significantly affect metabolism and proteoglycan synthesis in these cells. However, whether long noncoding RNA participate in cartilage homeostasis under hypoxia has not been reported yet. Here, we first identified LncZFHX2 as a lncRNA upregulated under physiological hypoxia in cartilage, specifically by HIF-1α. LncZFHX2 knockdown simultaneously accelerated cellular senescence, targeted multiple components of extracellular matrix metabolism, and increased DNA damage in chondrocytes. Through a series of in vitro and in vivo experiments, we identified that LncZFHX2 performed a novel function that regulated RIF1 expression through forming a transcription complex with KLF4 and promoting chondrocyte DNA repair. Moreover, chondrocyte-conditional knockout of LncZFHX2 accelerated injury-induced cartilage degeneration in vivo. In conclusion, we identified a hypoxia-activated DNA repair pathway that maintains matrix homeostasis in osteoarthritis cartilage.

Combined endoscope and low-temperature plasma knife for bilateral nasal vestibular cyst with sinus tract formation.

BACKGROUND: Nasal vestibular cyst is a non-dental cystic mass that occurs under the skin at the base of the nasal vestibule. The primary treatment is a transnasal endoscopic excision of the cyst wall at the base of the nose to open the cyst wall at the base of the nasal cavity, namely, marsupialization. METHODS: We present a patient with bilateral nasal vestibular cysts with sinus tract formation. This patient underwent marsupialization under general anesthesia because of the presence of facial swelling and other symptoms. RESULTS: After a 4-year follow-up, our studied case show a significantly improved radiological outcome and clinical prognosis. CONCLUSIONS: Compared to unilateral lesions, bilateral nasal vestibular cysts are more likely to be underdiagnosed due to the deceptive nature of the bilateral anatomy observed from the radiological findings. With this rare clinical case reported in this study, we hope our experience in diagnosis and treatment will provide a reference for otolaryngologist surgeons managing similar patients.

m6A modification confers thermal vulnerability to HPV E7 oncotranscripts via reverse regulation of its reader protein IGF2BP1 upon heat stress.

Human papillomavirus (HPV)-induced carcinogenesis critically depends on the viral early protein 7 (E7), making E7 an attractive therapeutic target. Here, we report that the E7 messenger RNA (mRNA)-containing oncotranscript complex can be selectively targeted by heat treatment. In HPV-infected cells, viral E7 mRNA is modified by N6-methyladenosine (m6A) and stabilized by IGF2BP1, a cellular m6A reader. Heat treatment downregulates E7 mRNA and protein by destabilizing IGF2BP1 without the involvement of canonical heat-shock proteins and reverses HPV-associated carcinogenesis in vitro and in vivo. Mechanistically, heat treatment promotes IGF2BP1 aggregation only in the presence of m6A-modified E7 mRNA to form distinct heat-induced m6A E7 mRNA-IGF2BP1 granules, which are resolved by the ubiquitin-proteasome system. Collectively, our results not only show a mutual regulation between m6A RNA and its reader but also provide a heat-treatment-based therapeutic strategy for HPV-associated malignancies by specifically downregulating E7 mRNA-IGF2BP1 oncogenic complex.

Distinct Roles of m5C RNA Methyltransferase NSUN2 in Major Gynecologic Cancers.

RNA methylation has recently emerged as an important category of epigenetic modifications, which plays diverse physiopathological roles in various cancers. Recent studies have confirmed the presence of 5-methylcytosine (m5C) modification on mammalian mRNAs, mainly modified by NOP2/Sun RNA methyltransferase family member 2 (NSUN2), but little is known about the underlying functions of m5C. Gynecologic cancers are malignancies starting from women's reproductive organs. The prevalence of gynecologic cancers leads to a massive economic burden and public health concern. In this study, we investigated the potential biological functions of NSUN2 in common gynecologic cancers including cervical cancer, ovarian cancer, and endometrial cancer. Remarkably, distinct scenarios were found. The levels of NSUN2 did not show alteration in endometrial cancer, and in ovarian cancer, depletion of upregulated NSUN2 did not reduce carcinogenesis in cancer cells, suggesting that the upregulated NSUN2 might be an incidental effect. On the contrary, NSUN2 played a role in tumorigenesis of cervical cancer; depletion of upregulated NSUN2 notably inhibited migration and invasion of cancer cells, and only wild-type but not catalytically inactive NSUN2 rescued these malignant phenotypes of cancer cells. Mechanistically, NSUN2 promoted migration and invasion by leading to m5C methylation on keratin 13 (KRT13) transcripts, and methylated KRT13 transcripts would be recognized and stabilized by an m5C reader, Y-box binding protein 1 (YBX1). Collectively, these results not only displayed the nature of diversity among human malignancies, but also demonstrated a novel NSUN2-dependent m5C-YBX1-KRT13 oncogenic regulatory pathway.

Modulation of Phase Separation by RNA: A Glimpse on N6-Methyladenosine Modification.

Phase separation is the driving force behind formation of various biomolecular condensates (BioMCs), which sub-compartmentalize certain cellular components in a membraneless manner to orchestrate numerous biological processes. Many BioMCs are composed of proteins and RNAs. While the features and functions of proteins are well studied, less attention was paid to the other essential component RNAs. Here, we describe how RNA contributes to the biogenesis, dissolution, and properties of BioMCs as a multivalence providing scaffold for proteins/RNA to undergo phase separation. Specifically, we focus on N6-methyladenosine (m6A), the most widely distributed dynamic post-transcriptional modification, which would change the charge, conformation, and RNA-binding protein (RBP) anchoring of modified RNA. m6A RNA-modulated phase separation is a new perspective to illustrate m6A-mediated various biological processes. We summarize m6A main functions as "beacon" to recruit reader proteins and "structural switcher" to alter RNA-protein and RNA-RNA interactions to modulate phase separation and regulate the related biological processes.

MiR-19-3p Induces Tumor Cell Apoptosis via Targeting FAS in Rectal Cancer Cells.

MicroRNAs are reported as a vital important factor in cancer cell initiation and progression processes. MicroRNA-19-3p has drawn the attention of many researchers in recent years because of its wide expression and its key role in serious kinds of tumor cells. However, the detailed mechanism of microRNA-19a-3p in these tumors is still poorly understood. So, in the present study, we aimed to explore the biological function and potential molecular mechanism of microRNA-19a-3p in different cancer cells. We first detect the relative level of miR-19a-3p in cancer cell lines and tumor tissues compared to normal cells and tissues. Results indicated the messenger RNA expression of microRNA-19a-3p existing in an aberrant low level in cancer cells and tissues. The overexpression of microRNA-19a-3p significantly reduced the cell proliferation, migration, and invasion ability in HCT116 cells. In addition to this, increased microRNA-19a-3p could induce cell apoptosis via promoting reactive oxygen species (ROS) accumulation, whereas inhibition of microRNA-19a-3p exhibited an opposite effect. Moreover, we predicated the target genes and the binding sites of microRNA-19a-3p and confirmed FAS as the targeting of microRNA-19a-3p through luciferase activity assay. Taken together, these results indicated that microRNA-19a-3p overexpression inhibited HCT116 cell proliferation, migration and invasion, induced cell apoptosis, and ROS accumulation via FAS targeting effect. It was conceivable that microRNA-19a-3p might serve as a potential molecular target for breast and liver cancer treatment.

Prognostic Factors for Primary Localized Gastrointestinal Stromal Tumors After Radical Resection: Shandong Gastrointestinal Surgery Study Group, Study 1201.

BACKGROUND: Most previous risk-prediction models for gastrointestinal stromal tumors (GISTs) were based on Western populations. In the current study, we collected data from 23 hospitals in Shandong Province, China, and used the data to examine prognostic factors in Chinese patients and establish a new recurrence-free survival (RFS) prediction model. METHODS: Records were analyzed for 5285 GIST patients. Independent prognostic factors were identified using Cox models. Receiver operating characteristic curve analysis was used to compare a novel RFS prediction model with current risk-prediction models. RESULTS: Overall, 4216 patients met the inclusion criteria and 3363 completed follow-up. One-, 3-, and 5-year RFS was 94.6% (95% confidence interval [CI] 93.8-95.4), 85.9% (95% CI 84.7-87.1), and 78.8% (95% CI 77.0-80.6), respectively. Sex, tumor location, size, mitotic count, and rupture were independent prognostic factors. A new prognostic index (PI) was developed: PI = 0.000 (if female) + 0.270 (if male) + 0.000 (if gastric GIST) + 0.350 (if non-gastric GIST) + 0.000 (if no tumor rupture) + 1.259 (if tumor rupture) + 0.000 (tumor mitotic count < 6 per 50 high-power fields [HPFs]) + 1.442 (tumor mitotic count between 6 and 10 per 50 HPFs) + 2.026 (tumor mitotic count > 10 per 50 HPFs) + 0.096 × tumor size (cm). Model-predicted 1-, 3-, and 5-year RFS was S(12, X) = 0.9926exp(PI), S(36, X) = 0.9739exp(PI) and S(60, X) = 0.9471exp(PI), respectively. CONCLUSIONS: Sex, tumor location, size, mitotic count, and rupture were independently prognostic for GIST recurrence. Our RFS prediction model is effective for Chinese GIST patients.

Regulatory mechanisms and clinical perspectives of circRNA in digestive system neoplasms.

A new star, circular RNA (circRNA), is a class of noncoding RNA with a stable cyclic structure. Exonic circRNA mainly exists in the eukaryotic cytoplasm. Intronic circRNAs (ciRNA) and exonic circRNAs with introns (EIciRNA) are found in the nucleus. Recent evidences showed the functional diversity of circRNAs, which could be microRNA (miRNA) sponges, interact with protein or translate into small peptide. Due to the change of human eating habits, digestive cancer remains one of the most common cancers worldwide and it is prone to metastasis. Increasing studies have found a number of circRNAs using RNA sequencing technology and displayed double roles of circRNA in digestive cancer. In this review, we surveyed the biogenesis and regulation of circRNAs, discussed circRNA functions and clinical applications (especially circRNAs in exosome) in digestive cancers, which implied that circRNAs could be as potential biomarkers in diagnosis and treatment of digestive cancers in the future.

[Analysis of gastric gastrointestinal stromal tumors in Shandong Province: a midterm report of multicenter GISSG1201 study].

OBJECTIVE: To summarize the treatment status of gastric gastrointestinal stromal tumor (GIST) in Shandong province,by analyzing the clinicopathological features and prognostic factors. METHODS: Clinicopathological and follow-up data of 1 165 patients with gastric GIST between January 2000 and December 2013 from 23 tertiary referral hospitals in Shandong Province were collected to establish a database. The risk stratification of all cases was performed according to the National Institutes of Health(NIH) criteria proposed in 2008. Kaplan-Meier method was used to calculate the survival rate. Log-rank test and Cox regression model were used for univariate and multivariate prognostic analyses. RESULTS: Among 1 165 cases of gastric GIST, 557 were male and 608 were female. The median age of onset was 60 (range 15-89) years. Primary tumors were located in the gastric fundus and cardia in 623 cases(53.5%), gastric body in 346 cases(29.7%), gastric antrum in 196 cases(16.8%). All the cases underwent resection of tumors, including endoscopic resection (n=106), local resection (n=589), subtotal gastrectomy(n=399), and total gastrectomy(n=72). Based on the NIH risk stratification, there were 256 cases (22.0%) at very low risk, 435 (37.3%) at low risk, 251 cases (21.5%) at intermediate risk, and 223 cases (19.1%) at high risk. A total of 1 116 cases(95.8%) were followed up and the median follow-up period was 40 (range, 1-60) months. During the period, 337 patients relapsed and the median time to recurrence was 34 (range 1-60) months. The 1-, 3-, and 5-year survival rates were 98.6%, 86.1% and 73.4%, respectively. The 5-year survival rates of patients at very low, low, intermediate, and high risk were 93.1%, 85.8%, 63.0% and 42.3% respectively, with a statistically significant difference (P=0.000). Multivariate analysis showed that primary tumor site (RR=0.580, 95%CI:0.402-0.835), tumor size (RR=0.450, 95%CI:0.266-0.760), intraoperative tumor rupture(RR=0.557, 95%CI:0.336-0.924), risk classification (RR=0.309, 95%CI:0.164-0.580) and the use of imatinib after surgery (RR=1.993, 95%CI:1.350-2.922) were independent prognostic factors. CONCLUSIONS: The choice of surgical procedure for gastric GIST patients should be based on tumor size. All the routine procedures including endoscopic resection, local excision, subtotal gastrectomy and total gastrectomy can obtain satisfactory curative outcomes. NIH classification has a high value for the prediction of prognosis. Primary tumor site, tumor size, intraoperative tumor rupture, risk stratification and postoperative use of imatinib are independent prognostic factors in gastric GIST patients.

Numerical simulation of the role of the utriculo-endolymphatic valve in the rotation-sensing capabilities of semicircular canals.

The utriculo-endolymphatic valve (UEV) has an uncertain function, but its opening and closure have been predicted to maintain a constant endolymphatic pressure within the semicircular canals (SCCs) and the utricle of the inner ear. Here, the study׳s aim was to examine the role of the UEV in regulating the capabilities of the 3 SCCs in sensing angular acceleration by using the finite element method. The results of the developed model showed endolymphatic flow and cupula displacement patterns in good agreement with previous experiments. Moreover, the open valve was predicted to permit endolymph exchange between the 2 parts of the membranous labyrinth during head rotation and, in comparison to the closed valve, to result in a reinforced endolymph flow in the utricle and an enhanced or weakened cupula deflection. Further, the model predicted an increase in the size of the orifice would result in greater endolymph exchange and thereby to a greater impact on cupula deflection. The model findings suggest the UEV plays a crucial role in the preservation of inner ear sensory function.

A biomechanical model of the inner ear: numerical simulation of the caloric test.

Whether two vertical semicircular canals can receive thermal stimuli remains controversial. This study examined the caloric response in the three semicircular canals to the clinical hot caloric test using the finite element method. The results of the developed model showed the horizontal canal (HC) cupula maximally deflected to the utricle side by approximately 3 µm during the hot supine test. The anterior canal cupula began to receive the caloric stimuli about 20 s after the HC cupula, and it maximally deflected to the canal side by 0.55 µm. The posterior canal cupula did not receive caloric stimuli until approximately 40 s after the HC cupula, and it maximally deflected to the canal side by 0.34 µm. Although the endolymph flow and the cupular deformation change with respect to the head position during the test, the supine test ensures the maximal caloric response in the HC, but no substantial improvement for the responses of the two vertical canals was observed. In conclusion, while the usual supine test is the optimum test for evaluating the functions of the inner ear, more irrigation time is needed in order to effectively clinically examine the vertical canals.

[Effect of septoplasty or in combination with out fracture of the inferior turbinate on the airflow field and nasal airway].

OBJECTIVE: To explore the effect of septoplasty or in combination with out fracture of the inferior turbinate in patients with nasal septum deviation on the airflow field and the nasal airway structure. METHODS: Six patients with nasal septum deviation underwent spiral CT imaging scans before surgery and during the follow-up. The 3D finite element meshes of the nasal airway were developed from the above CT scans. Given three preconditions, the nasal airflow fields were described by the Navier-Stokes and continuity equations at the inspiratory flow rate of 12 L/min. The whole airflow patterns were obtained and then compared with the airflow filed and airway structure changes before and after surgery. SPSS 12.0 software was used to analyze the data. RESULTS: Before surgery, area of the common airway and the middle and ventral medial regions in the concave side were (1.61 ± 0.18), (0.40 ± 0.10), (0.40 ± 0.14) cm(2) respectively, and those of convex side were (1.30 ± 0.18), (0.33 ± 0.05), (0.36 ± 0.10) cm(2) respectively. The differences between both sides were of no statistical significance (Z value was 1.782, 1.363, 0.526 respectively, all P > 0.05). Airflow of the above airways were (361 ± 68), (131 ± 25), (100 ± 28) ml respectively in concave side and (178 ± 33), (59 ± 26), (59 ± 18) ml respectively in convex side, which differences were significant statistically (Z value were 2.207, 2.201, 2.201 respectively, all P < 0.05). The inferior turbinate in concave side [(0.93 ± 0.10) cm] was statistically (Z = 2.214, P < 0.05) bigger than that in convex side [(0.58 ± 0.12) cm] before surgery. The airflow fields were in disorder in both ill-airways. After surgery, area of the common airway was (2.55 ± 0.44) cm(2) in concave side and (2.20 ± 0.72) cm(2) in convex side respectively, and area of the middle and ventral medial regions in the convex side were (0.58 ± 0.13), (0.81 ± 0.26) cm(2) respectively, which differences were of significance statistically when comparing to areas before surgery (Z value were 2.201, 2.201, 2.201, 2.201, P < 0.05). The airflow passed through nasal airway orderly in both sides. But the thickness of inferior turbinate was (0.73 ± 0.08) cm in concave side after surgery, which difference was significant statistically in comparison to that before surgery (Z = 2.264, P < 0.05). Consequently, nasal resistance decreased from (0.41 ± 0.03) kPa×L(-1)×s(-1) to (0.16 ± 0.01) kPa×L(-1)×s(-1) after surgery, the difference was significantly (Z = -2.207, P = 0.027). CONCLUSION: Septoplasty or in combination with out fracture of the inferior turbinate, followed by the self-adaptation consecutively, could improve the airway and breathing capacity of the nose.

[Analysis of the character of self-adaptation of nasal structure in patients with nasal septum deviation].

OBJECTIVE: To analyze the different characters of nasal airflow-field between 10 patients with nasal septum deviation and 20 healthy Chinese people by the method of three-dimensional reconstruction of these people's nasal cavity and numerical simulation of the flow field in these nasal cavity models. The character of airflow-field was considered by analyzing the relationship between the structure and function of the human nose. METHODS: Based on the data obtained from the CT images, 10 patients with nasal septum deviation and 20 healthy Chinese people's nasal cavity models were reconstructed by the method of surface rendering. The flow field in these three-dimensional models was simulated with finite element method. The different characters of nasal airflow-field was analysed between two groups of people. RESULTS: The airflow distribution in the nasal cavity model could be acquired from the simulation results of the velocity. The airflow for patients with nasal septum deviation mainly passed through the broad nasal cavity, especially in the middle part of meatus of nose. In the healthy people group, the airflow mainly passed through the main side of the nasal cavity, especially in the middle and inferior part of the meatus of nose. The pressure value at any point in the nasal cavity model could be obtained from the results of the pressure plot. In the patients with nasal septum deviation, the pressure mainly dropped in the part of the nasal septum deviation, accounting approximately 71.36% of the total pressure drop. In the group of healthy people, the pressure dropped mainly in the limen nasi, accounting approximately 58.78% of the total pressure drop. The nasal airway resistance of the patients with nasal septum deviation was larger than that in the group of healthy people. CONCLUSIONS: The three-dimensional nasal airway can reflect the characters of the human nasal airway. It can be used to analyze the change of the aerodynamic in nasal cavity caused by the abnormal anatomy of the nose. This experiment can proof that human nose has the function of self-adaptation, it can build a foundation for the construction of the model of self-adaptation of the human nose.

[The 3-D reconstruction of the nasal airway to model and analyze the airflow].

OBJECTIVE: To investigate the nasal airflow-field in relation with the structure and function of the human nose. METHOD: The 3-D finite-element mesh is developed from Spiral- CT imaging scans of the 25 healthy volunteers' noses. Given three preconditions, the nasal air-flow is described by the Navier-Stokes and continuity equations at the inspiratory flow rate of 10 min, then the whole airflow patterns are obtained for further analysis. RESULT: (1) In 5 cases, the airflow passes mainly through the middle medial region in both sides in the nasal airway. In remaining 20 cases, the airflow passes mainly through the middle and ventral medial regions in one side in the nasal cavity while little air passes through middle medial regions in another the other side through which little air passes. (2) The differences of velocity in the nasal valve, middle and ventral medial regions of the nasal airway between mainly side and non maingnot-mainly side are of statistical significance, while those in the olfactory split, middle and inferior meatuses in both sides are of no statistical significance. (3) In the mainly side, the most rapid air speed occurred in the nasal valve , the second rapid velocity in the middle medial region and the third in the ventral medial regions, the slowest velocity in the olfactory split, middle and inferior meatuses. In notion- mainly side, the velocity in all regions is slow without statistical significance. CONCLUSION: (1) At the inspiratory flow rate of 10 L/min, the middle and ventral medial regions act as the main airways in nasal cavity. (2) The airflow in nasal cavity can be directed effectively and reasonably by nasal valve, inferior turbinate, middle turbinate in turn, which may be consistent with the nasal cycle functionally.

[Structure of nasal cavity and characters of airflow].

OBJECTIVE: To study the airflow in nasal cavity by reconstructing 20 volunteers' nasal cavity models and numerical simulation of the flow field in these nasal cavity models. METHODS: Based on the data from the CT images, 20 volunteers' nasal cavity models were reconstructed by the method of surface rendering. The flow field in these three-dimensional models were simulated with finite element method. Some of these volunteers were tested by means of acoustic rhinometry and the test results recorded. Comparisons were performed for the curves from acoustic rhinometry and the results of numerical simulations. The simulation results were explained with the fluid network theory. RESULTS: The airflow distribution in the nasal cavity model could be acquired from the simulation results of the velocity plot. Main airflow would pass through the common nasal meatus in which flux accounted for 50% - 77% of overall flux. The pressure value at any point in the nasal cavity model could be obtained from the results of the pressure plot. The nasal airway resistance in the region of limen nasi accounted for 50% - 65% of overall nasal airway resistance. Comparing the test results with the simulation results the relation could be understood between the change of the cross-section area of nasal cavities and the plot of numerical simulation results of velocity and pressure in airflow field in the nasal cavity models. CONCLUSIONS: Comparing the simulated results of the 20 volunteers' nasal cavity model it can be concluded that the distribution of airflow in nasal cavities is not stationary. The differences among everybody's nasal cavity structure lead to the different airflow distribution in the nasal cavities.