Enhancing nasopharyngeal carcinoma cell radiosensitivity by suppressing AKT/mTOR via CENP-N knockdown.

OBJECTIVE: Investigating the impact of centromere protein N (CENP-N) on radiosensitivity of nasopharyngeal carcinoma (NPC) cells. METHODS: Using immunohistochemistry and immunofluorescence to detect CENP-N expression in tissues from 35 patients with radiosensitive or radioresistant NPC. Assessing the effect of combined CENP-N knockdown and radiotherapy on various cellular processes by CCK-8, colony formation, flow cytometry, and Western blotting. Establishing a NPC xenograft model. When the tumor volume reached 100 mm3, a irradiation dose of 6 Gy was given, and the effects of the combined treatment were evaluated in vivo using immunofluorescence and Western blotting techniques. RESULTS: The level of CENP-N was significantly reduced in radiosensitive tissues of NPC (p < 0.05). Knockdown of CENP-N enhanced NPC radiosensitivity, resulting in sensitizing enhancement ratios (SER) of 1.44 (5-8 F) and 1.16 (CNE-2Z). The combined treatment showed significantly higher levels of proliferation suppression, apoptosis, and G2/M phase arrest (p < 0.01) compared to either CENP-N knockdown alone or radiotherapy alone. The combined treatment group showed the highest increase in Bax and γH2AX protein levels, whereas the protein Cyclin D1 exhibited the greatest decrease (p < 0.01). However, the above changes were reversed after treatment with AKT activator SC79. In vivo, the mean volume and weight of tumors in the radiotherapy group were 182 ± 54 mm3 and 0.16 ± 0.03 g. The mean tumor volume and weight in the combined treatment group were 84 ± 42 mm3 and 0.04 ± 0.01 g. CONCLUSION: Knockdown of CENP-N can enhance NPC radiosensitivity by inhibiting AKT/mTOR.

The Issue of Recurrently Positive Patients Who Recovered From COVID-19 According to the Current Discharge Criteria: Investigation of Patients from Multiple Medical Institutions in Wuhan, China.

The current discharge criteria for COVID-19 require that patients have 2 consecutive negative results for reverse transcription polymerase chain reaction (RT-PCR) detection. Here, we observed that recurrent positive RT-PCR test results in patients with 3 consecutive negative results (5.4%) were significantly decreased compared with those in patients with 2 consecutive negative results (20.6%); such patients reported positive RT-PCR test results within 1 to 12 days after meeting the discharge criteria. These results confirmed that many recovered patients could show a positive RT-PCR test result, and most of these patients could be identified by an additional RT-PCR test prior to discharge.

Radiotherapeutic treatment of a fighter pilot with nasopharyngeal carcinoma.

BACKGROUND: Radiotherapy is the standard and most effective treatment for nasopharyngeal carcinoma (NPC) in its early stages. However, its application in fighter pilots returning to flying duties with NPC has not been previously reported, presumably due to post-radiotherapeutic complications. CASE REPORT: A 36-yr-old male fighter pilot had a painless mass in the left neck for 5 mo. Pathological diagnosis demonstrated nonkeratinizing squamous cell carcinoma in the left nasopharynx which had metastasized to lymph nodes in the left side of the neck. He was diagnosed and staged with NPC (T1N2M0) before treatment with radiotherapy and adjuvant chemotherapy. The patient suffered from catarrhal otitis media and xerostomia after 3 mo of radiotherapy, but these symptoms resolved. After a total of 8 mo of radiotherapy, he was in remission with no evidence of tumor recurrence or metastasis. He had normal Eustachian tube, hearing, and vestibular function before and after hypobaric chamber testing and passed all flight-related physical examinations. Consequently, he was granted a medical waiver and returned to flying status in two-seat fighter aircraft, flying for 53 h in a 12-mo period. After passing all flight-related tests again, he was then allowed to fly in single-seat aircraft. At the time of submission of this article, he has flown for 147 h and remained on flying status for 26 mo. He will be monitored annually for long-term effects of radiotherapy and/or disease recurrence. CONCLUSIONS: Fighter pilots with NPC may be safely considered for medical waiver with appropriate monitoring after successful treatment.

CENPN suppresses autophagy and increases paclitaxel resistance in nasopharyngeal carcinoma cells by inhibiting the CREB-VAMP8 signaling axis.

Chemotherapeutic resistance is one of the most common reasons for poor prognosis of patients with nasopharyngeal carcinoma (NPC). We found that CENPN can promote the growth, proliferation and apoptosis resistance of NPC cells, but its relationship with chemotherapeutic resistance in NPC is unclear. Here we verified that the CENPN expression level in NPC patients was positively correlated with the degree of paclitaxel (PTX) resistance and a poor prognosis through analysis of clinical cases. VAMP8 expression was significantly increased after knockdown of CENPN by transcriptome sequencing. We found in cell experiments that CENPN inhibited macroautophagy/autophagy and VAMP8 expression and significantly increased PTX resistance. Overexpression of CENPN reduced the inhibitory effects of PTX on survival, cell proliferation, cell cycle progression and apoptosis resistance in NPC cells by inhibiting autophagy. In turn, knockdown of CENPN can affect the phenotype of NPC cells by increasing autophagy to achieve PTX sensitization. Sequential knockdown of CENPN and VAMP8 reversed the PTX-sensitizing effect of CENPN knockdown alone. Experiments in nude mice confirmed that knockdown of CENPN can increase VAMP8 expression, enhance autophagy and increase the sensitivity of NPC cells to PTX. Mechanistic studies showed that CENPN inhibited the translocation of p-CREB into the nucleus of NPC cells, resulting in the decreased binding of p-CREB to the VAMP8 promoter, thereby inhibiting the transcription of VAMP8. These results demonstrate that CENPN may be a marker for predicting chemotherapeutic efficacy and a potential target for inducing chemosensitization to agents such as PTX.Abbreviations: 3-MA: 3-methyladenine; ATG5: autophagy related 5; CENPN: centromere protein N; CQ: chloroquine; CREB: cAMP responsive element binding protein; ChIP: chromatin immunoprecipitation assay; IC50: half-maximal inhibitory concentration; LAMP2A: lysosomal associated membrane protein 2A; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; NPC: nasopharyngeal carcinoma; NPG: nasopharyngitis; oeCENPN: overexpressed CENPN; PTX: paclitaxel; RAPA: rapamycin; RNA-seq: transcriptome sequencing; shCENPN: small hairpin RNA expression vector targeting the human CENPN gene; shCENPN-shVAMP8: sequential knockdown targeting the human CENPN gene and VAMP8 gene; shVAMP8: small hairpin RNA expression vector targeting the human VAMP8 gene; TEM: transmission electron microscopy; TIR: tumor inhibitory rate; VAMP8: vesicle associated membrane protein 8.

Flumatinib plus venetoclax as an effective therapy for Philadelphia chromosome-positive acute myeloid leukemia: A case report.

Philadelphia chromosome-positive acute myeloid leukemia (Ph + AML) is a rare type of AML with a low survival rate and poor prognosis. We first report a Ph + AML patient who remained in long-term remission after the combination of flumatinib and venetoclax, which could provide corresponding treatment ideas for clinical practice.

Combination of Venetoclax and Midostaurin Efficiently Suppressed Relapsed t(8;21)Acute Myeloid Leukemia With Mutant KIT After Failure of Venetoclax Plus Azacitidine Treatment.

Acute myeloid leukemia (AML) with t(8;21) is categorized as favorable-risk AML, but KIT mutations show a significantly poor prognostic impact in such patients. Persistent vulnerability to relapse is a major challenge in the treatment of this subtype of patients. Venetoclax is a BCL-2 selective inhibitor. The venetoclax+HMA strategy is also a notable salvage regimen that achieves good clinical outcomes in the treatment of relapsed or refractory (R/R) AML. However, in our clinical practice, we found that disease progressed rapidly even after venetoclax+azacitidine (AZA) therapy in two relapsed t(8;21) AML patients with KIT mutations. We report for the first time the therapeutic potential of venetoclax+midostaurin as a new combination therapy for relapsed t(8;21) AMLs with KIT mutations showing resistance to venetoclax+AZA therapy. Our ex vivo study also showed that midostaurin alone could inhibit proliferation and induce apoptosis of Kasumi-1 cells (e.g. Midostaurin induced G2 phase cell arrest, down-regulated p-KIT and BCL-2, while Bax protein levels were up-regulated) and observed a synergistic anti effect when the two drugs were combined. Our study shows that the venetoclax+midostaurin regimen may be a promising treatment option for R/R t(8;21) AML with KIT mutations.

The characteristics and evolution of pulmonary fibrosis in COVID-19 patients as assessed by AI-assisted chest HRCT.

The characteristics and evolution of pulmonary fibrosis in patients with coronavirus disease 2019 (COVID-19) have not been adequately studied. AI-assisted chest high-resolution computed tomography (HRCT) was used to investigate the proportion of COVID-19 patients with pulmonary fibrosis, the relationship between the degree of fibrosis and the clinical classification of COVID-19, the characteristics of and risk factors for pulmonary fibrosis, and the evolution of pulmonary fibrosis after discharge. The incidence of pulmonary fibrosis in patients with severe or critical COVID-19 was significantly higher than that in patients with moderate COVID-19. There were significant differences in the degree of pulmonary inflammation and the extent of the affected area among patients with mild, moderate and severe pulmonary fibrosis. The IL-6 level in the acute stage and albumin level were independent risk factors for pulmonary fibrosis. Ground-glass opacities, linear opacities, interlobular septal thickening, reticulation, honeycombing, bronchiectasis and the extent of the affected area were significantly improved 30, 60 and 90 days after discharge compared with at discharge. The more severe the clinical classification of COVID-19, the more severe the residual pulmonary fibrosis was; however, in most patients, pulmonary fibrosis was improved or even resolved within 90 days after discharge.

A Combined Histone Deacetylases Targeting Strategy to Overcome Venetoclax Plus Azacitidine Regimen Resistance in Acute Myeloid Leukaemia: Three Case Reports.

The management of patients with relapsed or refractory (R/R) acute myeloid leukaemia (AML) remains a challenge with few reliably effective treatments. Chidamide, a new selective HDAC inhibitor, has demonstrated some effectiveness in AML patients. Herein, we reported three patients with R/R AML who were unresponsive to venetoclax plus azacitidine (VA) but were successfully treated with VA when chidamide was added to the regimen. MCL1 is one of the anti-apoptotic proteins. Chidamide targets the MCL1 protein, which may permit venetoclax resistance when upregulated. We determined MCL1 protein expression in different AML cell lines, and chidamide could downregulate MCL1 expression in venetoclax resistance AML cells. In general, our experience showed that the chidamide/VA combination could improve the condition of R/R AML patients who are resistant to VA. Formally evaluating this regimen in R/R AML patients may be meaningful.

Factors affecting recurrent positive RT-PCR results in clinically cured COVID-19 patients: a multicenter study.

The aim of this study was to evaluate factors affecting the recurrence of positive RT-PCR results. By performing a retrospective analysis, we evaluated the clinical data of recurrent positive coronavirus disease 2019 (COVID-19) patients in multiple medical institutions in Wuhan. We recruited COVID-19 patients who were hospitalized from January 1 to March 10, 2020, in three tertiary hospitals in Wuhan, met the discharge criteria and received at least one additional nucleic acid test before leaving the hospital. According to the RT-PCR results, patients were split into a recurrent positive group (RPos group) and a nonrecurrent positive group (non-RPos group). Clinical characteristics, therapeutic schedules and antibody titers were compared between the two groups. AI-assisted chest high-resolution computed tomography (HRCT) technology was applied to investigate pulmonary inflammatory exudation and compare the extent of lung areas with different densities. This study involved 122 COVID-19 patients. There were no significant differences in age, sex, preexisting diseases, clinical symptoms, clinical classification, course of disease, therapeutic schedules or serum-specific antibodies between the two groups. A higher proportion of patients who showed pulmonary inflammatory exudation on HRCT scans were recurrent positive at the time of discharge than other patients (81.6% vs 13.7%, P < 0.01). In addition, the degree of pulmonary fibrosis was higher in the RPos group than in the non-RPos group (P < 0.05). Subpleural exudation at the peripheral edge of the lung and extensive pulmonary fibrosis at the time of discharge represent risk factors for the recurrence of COVID-19.