[The role and mechanism of lncRNA C9ORF139 targeting miR-24-3P/TAOK1 in regulating the proliferation of acute myeloid leukemia cells]

Objective: To investigate the role and mechanism of long non-coding RNA (lncRNA) C9ORF139 targeting micro RNA(miR)-24-3P/TAOK1 in regulating the proliferation of acute myeloid leukemia (AML) cells. Methods: AML cells HL-60 and THP-1 were purchased from the Chinese Academy of Sciences and divided into 4 groups:group A was negative control group (siNC group), group B was interference C9ORF139 group (siC9ORF139 group), group C was siC9ORF139+miR-24-3p inhibitor group, and group D was miR-24-3P+TAOK1 overexpression group (oe-TAOK1 group). Real-time fluorescence quantitative reverse transcription PCR was used to detect the expression levels of AML cell lines of HL-60 and THP-1 in four groups. Cell Counting Kit-8 assay was performed to measure cell proliferation. Flow cytometry was applied to analyze cell apoptosis. Transwell test was applied to detect cell migration and invasion ability. Western blot was used to detect p-serine/threonine kinase (p-raf) and p-mitogen activation proteinkinase (p-MEK), p-extracellular regulatory protein kinase (p-ERK) expression. The luciferase reporter gene plasmid was constructed to verify the binding ability of C9ORF139,miR-24-3P and TAOK1.Nude mice were inoculated with subcutaneous tumor cells of HL-60 (group A) and HL-60 (group B). Results: After the C9ORF139 gene was knocked down and cultured for 120 h, The cell proliferation ability (0.62±0.02, 0.82±0.02), migration ability (0.22±0.03, 0.05±0.01), invasion ability (0.20±0.02, 0.13±0.03) of group B were all lower than that of group A (1.30±0.02, 1.83±0.07; 0.99±0.02, 0.99±0.02; 1.00±0.01, 1.00±0.01) (all P<0.05). When co-transfected with miR-24-3 inhibitor, cell proliferation ability, migration ability and invasion ability were all higher in group B (all P<0.05). When co-transfected with miR-24-3P and oe-TAOK1 plasmid, cell proliferation ability, migration ability and invasion ability were all higher than group B (all P<0.05).When the C9ORF139 gene in the cells was knocked down, the apoptosis level of group B (28.56±8.07, 17.74±1.91) were higher than those of group A (0.31±0.27, 2.49±0.33)(all P<0.05); when co-transfected with miR-24-3P inhibitor, the apoptosis level (2.34±0.09, 3.06±0.06) were lower than those in group B (all P<0.05); when co-transfected with miR-24-3P and oe-TAOK1 in the plasmid group, the apoptosis level (2.16±1.29, 4.80±0.37) were also lower than those of group B (all P<0.05). In HL-60 and THP-1 cells, when C9ORF139 was not mutated, the luciferase activity of miR-24-3P group was lower than that of the miR-NC group (P<0.05). When the binding site with miR-24-3p in C9ORF139 sequence was mutated, the luciferase activity in miR-24-3p group was equivalent to that in miR-NC group (P>0.05).When TAOK1 was not mutated; the luciferase activity of miR-24-3P group was lower than that of group A (P<0.05). When the binding site with miR-24-3p in TAOK1 sequence was mutated, the luciferase activity in miR-24-3p group was equivalent to that in miR-NC group (P>0.05).When the C9ORF139 gene in HL-60 cells was knocked down and cultured for 72 h, the phosphorylation expression levels of Raf, MEK and ERK molecules in group B were significantly lower than those in group A (all P<0.05). By day 14, the tumor volume in the group A was greater than the tumor cell volume in the group B [(284.49±57.61) vs (125.70±18.64) mm³, P=0.017]. The tumor weight of HL-60 in group A was heavier than that of group B [(847.80±159.36) vs (408.40±113.16) mg, P=0.001]. Conclusions: LncRNA C9ORF139 regulates TAOK1 by sponging miR-24-3P to promote the proliferation, invasion and migration of acute myeloid leukemiacell.In vivo experiments have confirmed that the expression of C9ORF139 can promote the growth of subcutaneous tumors in AML nude mice.

613 The Floating Hip: A Distinct Injury Pattern? A Descriptive Study and Case-Control Analysis

Aim

A “Floating Hip” injury describes a simultaneous ipsilateral fracture of the femur and pelvis. We performed a descriptive study of the injury patterns, management, and outcomes of floating hip patients, and compared these patients to those with similar pelvic fractures without femoral involvement.

Method

This was a retrospective case-series review with secondary case-control analysis. Medical records of patients presenting with a floating hip injury to our tertiary orthopaedics department between 2015 and 2020 were reviewed. The control group comprised of patients with pelvic fractures but without associated femoral fractures, matched by age, sex, pelvic fracture classification, and mechanism of injury.

Results

46 Floating Hip cases were identified (34 males), of average age 39 (15-86) years. 20 had acetabular fractures, 21 had pelvic ring fractures and 5 had both fractures, concomitant with ipsilateral femoral fractures. The most common site of femoral fracture was mid-shaft (21.7%), followed by distal (19.6%). 69.6% of P/A fractures were managed surgically, with ORIF (43%) the most common option. 4 (12.50%) patients suffered complications, including 2 infections and 1 DVT. Compared to controls, Floating Hip patients were more likely to require surgical management (67.6% vs 47.8%, p = 0.03), and had higher rates of surgical complications (12.5% vs 4.6%), though not statistically significant (p = 0.3).

Conclusions

Our study describes the patterns, management, and outcomes of Floating Hip injuries, and observes differences in the management and complications compared to similar pelvic fractures without femoral involvement. These findings suggest Floating Hip cases may warrant consideration as a distinct injury pattern.

Association of body mass index with immune recovery, virological failure and cardiovascular disease risk among people living with HIV

OBJECTIVES

We conducted a longitudinal cohort analysis to evaluate the association of pre-treatment body mass index (BMI) with CD4 recovery, virological failure (VF) and cardiovascular risk disease (CVD) markers among people living with HIV (PLHIV).

METHODS

Participants who were enrolled between January 2003 and March 2019 in a regional Asia HIV cohort with weight and height measurements prior to antiretroviral therapy (ART) initiation were included. Factors associated with mean CD4 increase were analysed using repeated-measures linear regression. Time to first VF after 6 months on ART and time to first development of CVD risk markers were analysed using Cox regression models. Sensitivity analyses were done adjusting for Asian BMI thresholds.

RESULTS

Of 4993 PLHIV (66% male), 62% had pre-treatment BMI in the normal range (18.5-25.0 kg/m² ), while 26%, 10% and 2% were underweight (< 18.5 kg/m² ), overweight (25-30 kg/m2) and obese (> 30 kg/m² ), respectively. Both higher baseline and time-updated BMI were associated with larger CD4 gains compared with normal BMI. After adjusting for Asian BMI thresholds, higher baseline BMIs of 23-27.5 and > 27.5 kg/m² were associated with larger CD4 increases of 15.6 cells/µL [95% confidence interval (CI): 2.9-28.3] and 28.8 cells/µL (95% CI: 6.6-50.9), respectively, compared with normal BMI (18.5-23 kg/m² ). PLHIV with BMIs of 25-30 and > 30 kg/m² were 1.27 times (95% CI: 1.10-1.47) and 1.61 times (95% CI: 1.13-2.24) more likely to develop CVD risk factors. No relationship between pre-treatment BMI and VF was observed.

CONCLUSIONS

High pre-treatment BMI was associated with better immune reconstitution and CVD risk factor development in an Asian PLHIV cohort.

Expression Pattern of Tumor Necrosis Factor-α-Induced Protein 8-Like 2 in Acute Rejection of Cardiac Allograft

BACKGROUND

Tumor necrosis factor-α-induced protein-8 like-2 (TIPE2) is a negative regulator of innate immunity and cellular immunity, yet the expression pattern of TIPE2 in acute rejection of cardiac allograft remain enigmatic.

METHODS

We developed cardiac transplantation models and divided into 3 groups: a naive group, a syngeneic group, and an allogeneic group. Then, we detected the messenger RNA and protein of TIPE2 in cardiac allografts. Real-time polymerase chain reaction showed expression of CD4 and CD8 in the donor heart, and immunofluorescence assay revealed the association between T cells and TIPE2.

RESULTS

In our study, we first found that the expression of TIPE2 in cardiac allografts is upregulated compared with the syngeneic control, and increases in a time-dependent manner. The immunocytochemistry of heart grafts revealed a strong expression of TIPE2 in the inflammatory cells, but not in the cardiomyocytes. Finally, we proved that CD4⁺ and CD8⁺ T cells infiltrated cardiac allografts abundantly, which express ample TIPE2.

CONCLUSIONS

The upregulated expression of TIPE2 in cardiac allografts, mainly came from T cells, which infiltrated the donor heart. This finding indicates that there may be an association between TIPE2 and acute cardiac allograft rejection.

Academy of medicine, Singapore-Ministry of Health clinical practice guidelines: management of food allergy

The Academy of Medicine, Singapore (AMS) and the Ministry of Health (MOH) publish clinical practice guidelines to provide doctors and patients in Singapore with evidence-based guidance on managing important medical conditions. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the AMS-MOH clinical practice guidelines on the Management of Food Allergy, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Academy of Medicine website: http://www.ams.edu.sg/guidelines.asp#foodallergy. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

[Effect of microinjection of GABA into the caudate nucleus on electrical discharges of nociceptive neurons in caudate nucleus of rat]

The characteristics of glass microelectrode recorded electrical activity of nociceptive neurons in the caudate nucleus elicited by microinjection of GABA and blockage by picrotoxin (PIC) were studied in 53 Wistar rats. The results showed that GABA (25, 50, 100 micrograms/2 microliters every 2 min) inhibited the activity of pain excitation neurons (PEN), as shown by decreased frequency and increased latency, but enhanced the activity of pian, inhibition neurons (PIN), as shown by shortened duration and increased discharge frequency. Both activities are highly dose-dependent and could be blocked by PIC (i.p. 250 micrograms, 1 ml/1 min).