N⁶-methyladenosine (m⁶A) modification plays a critical role in cell cycle regulation, while the mechanism of m⁶A in regulating mitosis remains underexplored. Here, we found that the total m⁶A modification level in cells increased during mitosis by the liquid chromatography-mass spectrometry/mass spectrometry and m⁶A dot blot assays. Silencing methyltransferase-like 3 (METTL3) or METTL14 results in delayed mitosis, abnormal spindle assembly, and chromosome segregation defects by the immunofluorescence. By analyzing transcriptome-wide m⁶A targets in HeLa cells, we identified polo-like kinase 1 (PLK1) as a key gene modified by m⁶A in regulating mitosis. Specifically, through immunoblotting and RNA pulldown, m⁶A modification inhibits PLK1 translation via YTH N⁶-methyladenosine RNA binding protein 1, thus mediating cell cycle homeostasis. Demethylation of PLK1 mRNA leads to significant mitotic abnormalities. These findings highlight the critical role of m⁶A in regulating mitosis and the potential of m⁶A as a therapeutic target in proliferative diseases such as cancer.
Humans ; Polo-Like Kinase 1 ; Cell Cycle Proteins/metabolism* ; Proto-Oncogene Proteins/metabolism* ; Protein Serine-Threonine Kinases/metabolism* ; Mitosis/physiology* ; HeLa Cells ; Adenosine/genetics* ; Methyltransferases/metabolism* ; RNA, Messenger/metabolism* ; RNA-Binding Proteins/metabolism*

Objective:To explore the clinical effect of expanded scalp flaps in repconstructing the wounds after resection of frontal and facial nevus and scar.Methods:From May 2014 to May 2019, 28 patients (5 cases of nevus and 11 cases of scar in the frontal part and 2 cases of nevus, 9 cases of scar and 1 case of verrucous nevus in facial part) were repaired with expanded scalp flaps. According to the size of the lesion, the expander was selected and placed under the galea aponeurotica. After tissue expansion, the wound was reconstructed by random designed or pedicled skin flaps. The pedicled skin flaps took the branch of superficial temporal artery as the pedicle. The pedicle was cut off after 3 weeks. Hair removal by laser was performed 3 to 6 times 2 weeks after removing the suture.Results:In all the 28 cases, expansion in the first stage was sufficient, after skin flap transfer in the second stage, all survived without infection or local necrosis. After the pedicle division, 2 cases had small area of distal blood flow disorder, and the wound was healed after skin grafting The follow-up time ranged from 3 to 31 months. After hair removal by laser, the color and texture matched well with the normal skin in the adjacent area. No contracture and pigmentation occurred, and the effect was satisfactory.Conclusions:The scalp is a good donor site for expansion with sufficient tissue and few secondary deformities. The expanded scalp flap has good blood supply for repairing frontal and facial lesions, after hair removal by laser, the effect is good, and it is worth popularizing and applying.

Objective:To explore the clinical effect of expanded scalp flaps in repconstructing the wounds after resection of frontal and facial nevus and scar.Methods:From May 2014 to May 2019, 28 patients (5 cases of nevus and 11 cases of scar in the frontal part and 2 cases of nevus, 9 cases of scar and 1 case of verrucous nevus in facial part) were repaired with expanded scalp flaps. According to the size of the lesion, the expander was selected and placed under the galea aponeurotica. After tissue expansion, the wound was reconstructed by random designed or pedicled skin flaps. The pedicled skin flaps took the branch of superficial temporal artery as the pedicle. The pedicle was cut off after 3 weeks. Hair removal by laser was performed 3 to 6 times 2 weeks after removing the suture.Results:In all the 28 cases, expansion in the first stage was sufficient, after skin flap transfer in the second stage, all survived without infection or local necrosis. After the pedicle division, 2 cases had small area of distal blood flow disorder, and the wound was healed after skin grafting The follow-up time ranged from 3 to 31 months. After hair removal by laser, the color and texture matched well with the normal skin in the adjacent area. No contracture and pigmentation occurred, and the effect was satisfactory.Conclusions:The scalp is a good donor site for expansion with sufficient tissue and few secondary deformities. The expanded scalp flap has good blood supply for repairing frontal and facial lesions, after hair removal by laser, the effect is good, and it is worth popularizing and applying.

Objective:To explore the clinical effect of pre-expanded deltopectoral flap in the repair of faciocervical lesion and defect.Methods:From July 2004 to August 2018, 355 patients with faciocervical lesion and defect were admitted to the First Affiliated Hospital of Air Force Medical University, including 200 males and 155 females aged 4 to 48 years with major conditions including thermal burn scars, and type Ⅲ and Ⅳ facial-cervical deformities. During the stage Ⅰ skin soft tissue expander implantation surgery, according to the size and location of lesion and defect, expanders with appropriate volume were placed to expand the deltopectoral area. During the stage Ⅱ flap pedicled transposition surgery, after the expander was expanded to the desired volume, the impairment tissue was removed, the flap was designed according to the size of the defect (the unilateral defect area was 7 cm×5 cm to 17 cm×16 cm) and pedicled transposition was carried out. The incision in the chest donor area was directly sutured and closed. After the flap survived, stage Ⅲ flap delay and pedicle division surgery was carried out. The area of one single flap was 8 cm×5 cm to 20 cm×18 cm. The numbers of flaps and expanders, rated volume and expansion of expander, the intervals between surgeries in each stage, flap survival, postoperative complications in surgeries in each stage, and follow-up were recorded and analyzed.Results:A total of 460 pre-expanded deltopectoral flaps were used, including 250 unilateral flaps and 105 bilateral flaps. Totally 460 expanders were used in this group of patients. The rated volume was mostly 500 mL (163 expanders) and 600 mL (142 expanders). The expansion multiple of the expander was (1.14±0.19) times of the rated volume. The flap expansion time of the patients was (96±30) d, the pedicle time was (32±8) d, and the delay time was (7.5±1.6) d. The postoperative complications of patients mainly included infection (29 patients), expander exposure (18 patients), and hematoma (10 patients). During the follow-up of 6 to 120 months, the elasticity, texture, and color of the flaps of patients were similar to the surrounding tissue of the recipient area, and the face and neck were symmetrical, not bloated.Conclusions:The deltopectoral flap obtained by overexpansion has a larger area and a thinner thickness, and the elasticity, texture, and color are similar to the surrounding tissue of the recipient area. After transfer, a stable appearance of the face and neck can be obtained. The main complications are infection and expander exposure, most of which occurred after stage Ⅰ skin soft tissue expander implantation surgery.

Objective: To explore the clinical effects of expanded forehead flaps in repairing midfacial defects. Methods: From January 2003 to December 2018, 19 patients with midfacial defects were admitted to our unit, including 8 males and 11 females, aged 7 to 52 years. One cylindrical expander with rated capacity ranged from 100 to 170 mL was placed in the forehead of patients in the first stage of expansion, and the total water injection volume was about 2 times of the rated capacity of the expander during 1 to 2 months. The area of midfacial defects was 4 cm×2 cm to 9 cm×5 cm after resection in the second stage surgery. Expanded forehead flaps with vascular pedicle of supratrochlear vessels or frontal branch of superficial temporal vessels were used to repair the midfacial defects, with flap size ranging from 5 cm×2 cm to 16 cm×6 cm. The donor sites were closed by direct suturing. Three weeks later, the pedicle was divided. The complications, blood supply after flap transfer and pedicle division, and the treatment effects during follow-up were observed. Results: Among the patients, flaps of 11 patients had vascular pedicle of supratrochlear vessels; flaps of 8 patients had vascular pedicle of frontal branch of superficial temporal vessels. All the flaps survived with no complications and good blood supply after flap transfer and pedicle division. During the follow-up of 6 to 12 months after the third stage surgery of pedicle division of 12 patients, no lower eyelid ectropion occurred, the appearance of the flaps was similar to the surrounding tissue with no swelling. Conclusions The application of expanded forehead flaps can not only repair the defects but also effectively avoid the complication of lower eyelid ectropion, which is a promising method in repairing midfacial defects.

Objective: To investigate the functional recovery and cosmetic effects of pre-expanded pedicled deltopectoral flap. Methods: From January 2008 to December 2018, 42 patients with 56 pre-expanded pedicled deltopectoral flaps from Xijing Hospital of Air Force Military Medical University were followed up at least 6 months. 18 of them were male, the remaining were female. And the average age was (24.7±7.3) years. Then the indicators were tested and evaluated. Tubes with different temperatures were used for temperature sensation test. The flaps were stabbed using a 27 G blunt needle to test algesthesia. Tactile threshold was measured by Semmes-Weinstein monofilament. Two-point discrimination was measured by Disk-Criminator. Elasticity of skin flaps was measured by CK-MC®960. Colors of skin flaps were analyzed by ANTERA®3D system, including L^*a^*b^*, melanin and hemoglobin content. And the postoperative scars were evaluated by the Patient and Observer Scar Assessment Scale (POSAS). The flap retraction rate [(flap area immediately after operation-flap area at the follow-up time)/flap area immediately after operation]was calculated. The satisfaction of patients, doctors and third parties was investigated as well. Statistical analysis of data was performed with SPSS 23.0, satisfaction rate was expressed as percentages. Scar scores were compared by Wilcoxon rank sum test. The values of elasticity, color L^*a^*b^*, melanin and hemoglobin between skin flaps and normal skin were analyzed by paired t test. The difference was statistically significant at P<0.05. Results: The scores of pain, heat and cold sensation were (4.61±0.78), (3.48±0.90) and (4.39±0.81), the tactile threshold was (0.26±0.23) g/mm², and the distance of two-point discrimination was (10.09±4.79) mm. There was no significant difference in elasticity, color b^*and melanin content between skin flap and normal skin of face and neck (P>0.05). The color of flap L^*, a^*and hemoglobin content of flaps were significantly different from those of normal skin from face and neck (P<0.05). The result of self-assessment of patients (POSAS) showed that there were significant differences (P<0.05) in pain, itch and stiffness between facial and chest donor scar. The result of observer evaluation (POSAS) showed that the scar score for all items around facial flap was better than that of chest donor area, the difference was statistically significant (P<0.05), and the retraction rate of flaps was (10.44 ±3.36)%. The satisfaction rates of doctors, patients and the third party were 92.86% (39/42), 71.43% (30/42) and 61.90% (26/42), respectively. Conclusions Excellent functional recovery and reliable cosmetic effect were observed in the facial-cervical scar repair with pre-expanded pedicled deltopectoral flap. Transfer of pre-expanded pedicled deltopectoral flap is an effective method for the treatment of facial-cervical scars.