Abstract 817: microRNA-26a-5p is a prognostic factor that regulates cancer stemness

Background: Cancer stem cells (CSCs) identified in lung cancer exhibit resistance to chemotherapy, radiotherapy, and targeted therapy. Therefore, a technology to control of CSCs is needed to overcome such resistance to cancer therapy. Various evidences about the association between epithelial-mesenchymal transition related transcriptomic alteration and acquisition of CSC phenotype have been proposed recently. In our previous research, down-regulated miR-26a-5p is closely related to mesenchymal-like lung cancer cell lines. These findings suggest that miR-26a-5p might be involved in lung cancer stemness.

Methods: RNA polymerase III subunit G (POLR3G) was selected as a candidate target of miR-26a-5p related to cancer stemness. its quantitative relationship was investigated by polymerase chain reaction, western blot after transfection of miR-26a-5p. luciferase assay were done for investigating the direct regulation of miR-26a-5p on POLR3G expression. After transfection of miR-26a-5p, colony formation assay and sphere formation assay were performed to evaluate the effect on cancer stemness. By treating cancer cell by miR-26a-5p and paclitaxel, cell viability was checked by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and Muse cell analyzer. Expression level of each gene and its impact on survival were revealed by the cancer genome atlas pancancer database.

Results: miR-26a-5p regulated the expression of POLR3G directly. Overexpression of miR-26a-5p induced down regulation of POLR3G and a marked reduction of colony formation and sphere formation. Co-treatment of miR-26a-5p with paclitaxel decreased cell growth, suggesting that miR-26a-5p might play a role as a chemotherapy sensitizer. In the cancer genome atlas data, down-regulated miR-26a-5p and up-regulated POLR3G were shown compared to adjacent normal tissue. High miR-26a-5p and low POLR3G expression were also related to higher survival rate of patients with lung adenocarcinoma.

Conclusions: Overexpression of miR-26a-5p can suppress lung cancer stemness and make cancer cell become sensitive to chemotherapy. This finding provides a novel insight into a potential lung cancer treatment by regulating stemness.

Citation Format: Daeun Kang, Chang Ryul Park, Minhyeok Lee, Su Yel Lee, Se Jin Park, Wan Jin Hwang, Gwan Woo Ku, Seong Lan Yu, In Beom Jeong, Sun Jung Kwon, Jaeku Kang, Eung Bae Lee, Ji Woong Son. microRNA-26a-5p is a prognostic factor that regulates cancer stemness [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 817.

Safety and feasibility of hybrid tracheostomy

Background

Percutaneous dilatational tracheostomy (PDT) is widely used in intensive care units, but this conventional method has some disadvantages, such as requirement of a lot of equipment and experts at the site. Especially, in situations where the patient is isolated due to an infectious disease, difficulties in using the equipment may occur, and the number of exposed persons may increase. In this paper, we introduce hybrid tracheostomy that combines the advantages of surgical tracheostomy and PDT and describe our experiences.

Methods

Data from 55 patients who received hybrid tracheostomy without bronchoscopy from January 2020 to February 2021 were collected and reviewed retrospectively. Hybrid tracheostomy was performed at the bedside by a single thoracic surgeon. The hybrid tracheostomy method was as follows: after the skin was incised and the trachea was exposed, only the extent of the endotracheal tube that could not be removed was withdrawn, and then tracheostomy was performed by the Seldinger method using a PDT kit.

Results

The average age was 66.5 years, and the proportion of men was 69.1%. Among the patients, 21.8% were taking antiplatelet drugs and 14.5% were taking anticoagulants. The average duration of the procedure was 13.3 minutes. There was no major bleeding, and there was one case of paratracheal placement of the tracheostomy tube.

Conclusions

In most patients, the procedure can be safely performed without any major complications. However, patients with a short neck, a neck burn or patients who have received radiation therapy to the neck should be treated with conventional methods.

Effects of dexamethasone on catheter-related bladder discomfort and emergence agitation: A prospective, randomized, and controlled trial

Background

Catheter-related bladder discomfort (CRBD) is common in patients with a urinary catheter and is a risk factor for emergence agitation (EA). The mainstay of CRBD management is anticholinergics. Dexamethasone inhibits acetylcholine release. This study aimed to evaluate the effects of dexamethasone on postoperative CRBD and EA.

Methods

In this prospective study, 90 patients undergoing urological surgery requiring urinary catheterization were allocated randomly to one of two groups (each n = 45). Before induction of anesthesia, the dexamethasone group received 10 mg (2 ml) of dexamethasone intravenously, while the control group received 2 ml of saline in the same manner. The incidence and severity of CRBD were assessed 0, 1, 2, and 6 h after the patient arrived in the post-anesthesia care unit (PACU) as the primary outcomes. The incidence and severity of EA were also compared during emergence and recovery from anesthesia as secondary outcomes.

Results

The incidences of CRBD in the control group and dexamethasone group at 0, 1, 2, and 6 h postoperatively were 28.9% and 15.6%, 55.6% and 55.6%, 57.8% and 46.7%, and 53.3% and 51.1%, respectively. The incidence and severity of CRBD assessed at 0, 1, 2, and 6 h postoperatively did not show intergroup differences. The incidence and severity of EA in the operating room and PACU also showed no difference between the groups.

Conclusions

Dexamethasone (10 mg) administered before induction of anesthesia did not further reduce the incidence or severity of CRBD or EA in patients undergoing urological surgery.

LncRNA LINC00240 suppresses invasion and migration in non-small cell lung cancer by sponging miR-7-5p

Background

lncRNAs have important roles in regulating cancer biology. Accumulating evidence has established a link between the dysregulation of lncRNAs and microRNA in cancer progression. In previous studies, miR-7-5p has been found to be significantly down-regulated in mesenchymal-like lung cancer cell lines and directly regulated EGFR. In this work, we investigated the lncRNA partner of miR-7-5p in the progression of lung cancer.

Methods

We investigated the expression of miR-7-5p and the lncRNA after transfection with an miR-7-5p mimics using a microarray. The microarray results were validated using quantitative real time-polymerase Chain Reaction (qRT-PCR). The regulatory effects of lncRNA on miR-7-5p and its target were evaluated by changes in the expression of miR-7-5p after transfection with siRNAs for lncRNA and the synthesis of full-length lncRNA. The effect of miR-7-5p on lncRNA and the miRNA target was evaluated after transfection with miRNA mimic and inhibitor. The role of lncRNA in cancer progression was determined using invasion and migration assays. The level of lncRNA and EGFR in lung cancer and normal lung tissue was analyzed using TCGA data.

Results

We found that LINC00240 was downregulated in lung cancer cell line after miR-7-5p transfection with an miR-7-5p mimic. Further investigations revealed that the knockdown of LINC00240 induced the overexpression of miR-7-5p. The overexpression of miR-7-5p diminished cancer invasion and migration. The EGFR expression was down regulated after siRNA treatment for LINC00240. Silencing LINC00240 suppressed the invasion and migration of lung cancer cells, whereas LINC00240 overexpression exerted the opposite effect. The lower expression of LINC00240 in squamous lung cancer was analyzed using TCGA data.

Conclusions

Taken together, LINC00240 acted as a sponge for miR-7-5p and induced the overexpression of EGFR. LINC00240 may represent a potential target for the treatment of lung cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07755-8.

Thoracic Scoliosis in Patients with Primary Spontaneous Pneumothorax

Background

Primary spontaneous pneumothorax (PSP) affects patients without clinically apparent lung disorder found in tall and thin young male. Scoliosis refers to curves exceeding 10° Cobb angle observed through chest X-ray and affects 2% to 4% of adolescents. Both conditions are commonly encountered in primary health care setting. The aim of this study is to access the correlation of thoracic scoliosis and PSP in adolescent.

Methods

A retrospective analysis was conducted for patients diagnosed for PSP in Konyang University Hospital between January 2010 and March 2017. Chest X-rays of 222 patients and 155 normal control (NC) cases were reviewed to measure the Cobb angle. Greater than 10° of Cobb angle is diagnosed as scoliosis.

Results

Scoliosis in patient with PSP has higher incidence than that of NC group (p<0.001). Median value of Cobb angle is 12.9° in PSP group and 14.7° in NC group. Directional relationship between scoliosis and pneumothorax in PSP group is also observed; 40.5% cases are ipsilateral and 59.5% are contralateral.

Conclusion

PSP patients tend to have thoracic scoliosis more commonly compared with normal healthy adolescent. Scoliosis may contribute to heterogeneity of alveolar pressure which exacerbates subpleural bleb formation that can cause pneumothorax. The causal relationship is unclear and further studies are needed in the future.

Unusual Pseudoaneurysm of the Dorsalis Pedis Artery after an Iatrogenic Injury

Aneurysm and pseudoaneurysm of the dorsalis pedis artery (DPA) are rare vascular entities. Pseudoaneurysms of the DPA are commonly due to blunt trauma, sharp penetrating injury, fracture, or iatrogenic injury. Herein, we report the case of a patient with a rare iatrogenic pseudoaneurysm that occurred after blood sampling. The diagnosis was suspected based on palpitation of a pulsatile mass on the dorsal foot and confirmed by color Doppler ultrasound and computed tomography angiography. Surgical treatment was successfully performed by reconstruction with an autologous venous graft. The patient recovered well, with no ischemic complications.