Acute upper airway obstruction due to cervical hematoma after cervicofacial liposuction.

Liposuction is a surgical procedure performed worldwide. Although many fatal complications of liposuction have been reported, to our knowledge, no cases of fatal liposuction complications specifically related to the face region have been reported. Here, we present a case of a woman in her 30s who developed a cervical hematoma and upper airway obstruction following facial liposuction. We present this unique case to highlight the rare occurrence of fatal complications specific to facial liposuction. The patient underwent liposuction during surgery at a cosmetic surgical clinic and awoke from anesthesia after the procedure. Two hours later, she developed a neck swelling and dyspnea. While the anesthesiologist managed her airway, she went into cardiopulmonary arrest. She was then transferred to the emergency room but died on day 7 of hospitalization. The autopsy revealed swelling of the right cheek and mandible, a subcutaneous hematoma in the same area, and laryngeal edema. A damaged facial artery branch was identified, which was consistent with the computed tomography (CT) findings on admission. CT also showed that the hematoma compressed the right internal jugular vein, suggesting that venous outflow impairment caused by the hematoma may have exacerbated the airway obstruction. This case reveals that cervical hematoma caused by facial liposuction can cause fatal upper airway obstruction and the onset of the hematoma may be gradual.

Impact of chronic kidney disease stages on surgical and functional outcomes in robot-assisted partial nephrectomy for localized renal tumors.

The influence of chronic kidney disease stage on robot-assisted partial nephrectomy outcomes remains underexplored. This study aimed to assess the impact of chronic kidney disease stage on functional and surgical outcomes of robot-assisted partial nephrectomy and identify preoperative predictors of significant postoperative 1-year renal-function loss (RFL). Clinical data of 408 patients who underwent robot-assisted partial nephrectomy at Yokohama City University Hospital between 2016 and 2023 were retrospectively reviewed. The da Vinci Surgical System was applied in all patients, and outcomes assessed included surgical parameters, postoperative estimated glomerular filtration rate, trifecta and pentafecta achievements, and complications. Significant RFL was defined as estimated glomerular filtration rate reduction ≥ 25% from baseline. Higher chronic kidney disease stages correlated with older age, hypertension, diabetes, and solitary kidneys. Postoperative estimated glomerular filtration rate decline was most pronounced in patients with chronic kidney disease stages 4-5. Although the chronic kidney disease stage did not significantly affect most surgical parameters, pentafecta achievement was higher in patients with chronic kidney disease stage 3 than in those with stages 4-5. Two patients required hemodialysis after robot-assisted partial nephrectomy. Multivariable logistic regression analysis showed that preoperative hemoglobin level and maximum tumor diameter were significant predictive factors for significant RFL. In conclusion, preoperative CKD stage did not influence on surgical outcome except for pentafecta achievement. RAPN may be feasible for patients with CKD stages 4-5 because of no rapid progression to hemodialysis induction and no procedure-related mortality. Preoperative hemoglobin levels and tumor diameter emerged as predictors of significant RFL.

Surgical proficiency in laparoscopic radical cystectomy with extracorporeal urinary diversion and its adequacy for the execution of robot-assisted radical cystectomy with intracorporeal urinary diversion.

INTRODUCTION: The number of facilities adopting intracorporeal urinary diversion (ICUD) using robots instead of extracorporeal urinary diversion (ECUD) is increasing. However, guidance on how to introduce robot-assisted radical cystectomy (RARC) + ICUD in each urological institute remains unclear. This study aimed to verify the feasibility of the transition from laparoscopic radical cystectomy (LRC) + ECUD to RARC + ICUD. METHODS: We retrospectively analyzed 26 consecutive patients who underwent ICUD with an ileal conduit after RARC between 2018 and 2020 (RARC + ICUD early group). We then compared these patients with 26 consecutive patients who underwent ECUD with an ileal conduit after LRC between 2012 and 2019 (LRC + ECUD late group) at Yokohama City University Hospital. RESULTS: In the RARC + ICUD early group compared with the LRC + ECUD late group, the median total operation time was 516 versus 532.5 min (P = .217); time to cystectomy, 191 versus 206.5 min (P = .234); time of urinary diversion with an ileal conduit, 198 versus 220 min (P = .016); postoperative maximum C-reactive protein levels, 6.98 versus 12.46 mg/L (P = .001); number of days to oral intake, 3 versus 5 days (P = .003); length of hospital stay, 17 versus 32 days (P < .001). The postoperative complication rates (within 90 days) were 23.1% and 42.3% in the RARC + ICUD early and LRC + ECUD late groups, respectively (P = .237). Clavien-Dindo classification ≥3 was noted in 1 and 4 patients in the RARC + ICUD early and LRC + ECUD late groups, respectively (P = .350). CONCLUSION: Regarding perioperative outcomes, the RARC + ICUD early group was not inferior to the LRC + ECUD late group. This study suggests the feasibility of a transition from LRC + ECUD to RARC + ICUD.

Enfortumab vedotin prolongs overall survival in metastatic urothelial carcinoma following pembrolizumab therapy in real-world data.

OBJECTIVE: In December 2021, enfortumab vedotin (EV), an antibody-drug conjugate directed against nectin-4, was approved in Japan as a new treatment after platinum-containing chemotherapy and PD-1/PD-L1 inhibitors. This study evaluated, using real-world data, the efficacy and safety of EV therapy in patients with metastatic urothelial carcinoma (mUC). MATERIALS AND METHODS: Fifty-five patients with mUC who discontinued pembrolizumab therapy due to disease progression between June 2018 and April 2023 at Yokohama City University Hospital were evaluated retrospectively. Of the 55 patients, 25 received EV therapy (EV group) and 30 did not (non-EV group). All patients who underwent EV therapy were diagnosed with disease progression after the approval of EV in Japan. RESULTS: The median (range) follow-up period after pembrolizumab discontinuation was 6.3 (0.7-31.1) months. There were eight (32.0%) deaths due to cancer in the EV group and 27 (90.0%) in the non-EV group. The overall survival (OS) after pembrolizumab discontinuation was not reached in the EV group versus 2.6 months in the non-EV group (p < 0.001). A multivariate analysis revealed that EV therapy (EV vs. non-EV group; hazard ratio 0.26; 95% confidence interval 0.16-0.41; p < 0.001) was an independent prognostic factor for OS. CONCLUSION: EV prolonged OS in mUC following pembrolizumab therapy in real-world data.

Impacts of Complete Endophytic Renal Tumors on Surgical, Functional, and Oncological Outcomes of Robot-Assisted Partial Nephrectomy.

Objective: Complete endophytic renal tumors (CERTs) are the most challenging for robot-assisted partial nephrectomy (RAPN). This study aimed to determine the impact of CERT on outcomes of RAPN. Methods: All RAPN cases for localized renal tumor undertaken at Yokohama City University Hospital between 2016 and 2023 were enrolled. Tumor characteristics and surgical, functional, and oncologic outcomes of RAPN were compared between CERT and non-CERT groups. Results: Consecutive 666 patients were enrolled, and 76 (11.4%) were identified as CERT (3 points of "E" score). CERT showed smaller tumor diameters (p < 0.001), more predominant hilar tumor (p = 0.029), higher "N" scores (p < 0.001) and "L" scores (p = 0.006) than non-CERT. The CERT group showed longer warm ischemia times (p < 0.001), more frequent positive surgical margins (p = 0.028), and relatively lower trifecta achievement rates (p = 0.101) than the non-CERT group. In multivariable analysis, the CERT was an independent predictor for trifecta achievement but not for pentafecta achievement. Conclusions: CERT was associated with longer warm ischemia time, positive surgical margin, and lower trifecta achievement, but not with surgical complication and pentafecta achievement in RAPN. This study suggested that CERT had limited influence on long-term renal functional preservation; however, it had strong impacts on short-term surgical outcome.

Comparison of perioperative outcomes and complications between intracorporeal, extracorporeal, and hybrid ileal conduit urinary diversion during robot-assisted radical cystectomy: a comparative propensity score-matched analysis from nationwide multi-institutional study in Japan.

BACKGROUND: To investigate the impact of different urinary diversion (UD) techniques on the peri- and postoperative complications of robot-assisted radical cystectomy (RARC) with ileal conduit. METHODS: We retrospectively analyzed 373 patients undergoing RARC with ileal conduit at 11 institutions in Japan between April 2018 and December 2021. Propensity score weighting was performed to adjust for confounding factors such as age, sex, body mass index, performance status, American Society of Anesthesiologists score, previous abdominal surgery, neoadjuvant chemotherapy, and preoperative high T stage (≥ cT3) and high N stage (≥ cN1). Perioperative complications were then compared among three groups: extracorporeal, intracorporeal, and hybrid urinary diversion (ECUD, ICUD, and HUD, respectively). RESULTS: A total of 150, 68, and 155 patients received ECUD, HUD, and ICUD, respectively. Bowel reconstruction time and UD time were significantly shorter in the ECUD group (p < 0.001), and console time was significantly longer and blood loss was significantly higher in the ICUD group (p < 0.001). For postoperative complications (Clavien-Dindo Classification grade ≥ 3), surgical site infection (p = 0.004), pelvic abscess (p = 0.013), anastomotic urine leak (p = 0.007), and pelvic organ prolapse (p = 0.011) significantly occurred in the ECUD group. For all grades, ileus was more common in the HUD group, whereas anastomotic stricture was more common in the ECUD group compared with the other groups (p < 0.05). CONCLUSIONS: Severe complications did not increase after HUD and ICUD compared with ECUD; however, console time tended to be longer and blood loss was slightly higher during RARC.

Alcohol and toxicological factors influencing fatal falls from height in the Greater Tokyo Area: a retrospective study.

Falls from height pose a significant public health concern in urban regions, including the highly urbanized Greater Tokyo Area. The Japanese population is characterized by high rates of suicide and psychoactive drug usage, underscoring the importance of investigating these attributes in falls from height. This study aimed to retrospectively analyze the alcohol and toxicological aspects influencing falls from height in the Greater Tokyo Area between 2014 and 2022 and compare the findings with existing reports on other populations. In total, 75 cases of falls from height and 159 cases of natural deaths were included. Consistent with previous findings, Fisher's exact test revealed a predominance of males (66.67%, 50/75) and young adults (57.33%, 43/75) in falls from height. Multivariate logistic regression analysis identified antidepressant usage as the most significant risk factor within the target population, while younger individuals under alcohol influence constituted another high-risk group. Notably, contradictory to other populations, female individuals involved in fatal falls in the Greater Tokyo Area exhibited a higher frequency of alcohol consumption than males (48.00%, 12/25 vs. 26.00%, 13/50), and most of them were associated with suicide (83.33%, 10/12). These findings elucidate the population characteristics that pose a high risk for fatal falls from height in Japan and can serve as a reference for other Asian populations residing in similar megacities.

Increased fatty acid synthesis and disturbed lipid metabolism in Neuro2a cells after repeated cocaine exposure: A preliminary study.

Chronic use of cocaine prompts neurodegeneration and neuroinflammation. Lipids play pivotal roles in neuronal function and pathology. Although evidence correlates cocaine use with the alteration of lipid metabolism in blood and brain, the precise mechanism remains to be elucidated. In this study, we explore the effect of cocaine on neuronal fatty acid profiles in vitro. Neuro2a cells following seven days of repeated exposure to cocaine (0, 600, 800, 1000 µM) showed apoptosis-irrelevant cell death, dysregulated autophagy, activation of atypical endoplasmic reticulum stress response, increased saturated and unsaturated fatty acid synthesis, and disrupted lipid metabolism. These preliminary findings indicated the association between lipid metabolism and cocaine-induced neurotoxicity, which should be beneficial for understanding the neurotoxicity of cocaine.

Ectopic myogenesis and fibrosis accompany adipogenesis during thymic involution induced by repeated cocaine administration.

We have shown previously that daily cocaine administration for 7-14 days in rats resulted in the acceleration of thymic involution, which is, alike to age-related thymic involution, accompanied by ectopic adipogenesis. Here we show that the thymic involution caused by repeated cocaine administration is accompanied by not only adipogenesis but also ectopic myogenesis and fibrosis. In accordance with fibrosis, we observed an increase of N-cadherin, a marker of mesenchymal cells, as well as a decrease of E-cadherin, an epithelial cell marker, in the thymus in response to cocaine administration, suggesting the occurrence of epithelial-to-mesenchymal transition (EMT). Levels of fibronectin was also increased in the thymus of cocaine group compared to control group. In addition, increases in the levels of the transcription factors for myogenic differentiation, myogenin, MYF5, and MYF6, were observed in the thymus administered cocaine for 14 days. These results indicate that the thymic involution induced by cocaine administration involves not only adipogenesis and fibrosis but also ectopic myogenesis, which is scarcely observed and rather pathological process during thymic involution.

Case report: Fatal ischemic stroke induced by unruptured traumatic intracranial vertebral artery dissection.

Intracranial vertebral artery dissection (IVAD) is rare and potentially fatal due to the risk of secondary subarachnoid hemorrhage once ruptured. Unruptured traumatic IVAD is even rarer and can result in ischemic stroke, yet mostly benign when timely diagnosed. Herein, we present an uncommon case of a patient who underwent a fatal ischemic stroke induced by unruptured traumatic IVAD. The patient was symptomatic soon after being physically assaulted but left untreated until acute deterioration for multiple brain infarctions occurred, secondary to IVAD-induced cerebellar stroke. Fifteen days later, he died, regardless of an urgently performed thrombectomy. Multiple serial histologic examinations revealed an unruptured dissection of the intracranial vertebral artery with a slit-like tear of the intimal and medial layers, considered to be the culprit lesion. The 15-day prolonged onset of stroke was rare in traumatic IVADs. Furthermore, the slit-like tear of the intimal layer in our case may support the initial intimal laceration hypothesis for VAD pathogenesis. Since limited pathohistological information is available regarding ischemic IVAD, we believe this rare case will be beneficial in understanding the pathophysiology of ischemic IVAD.

Administration of Enfortumab Vedotin after Immune-Checkpoint Inhibitor and the Prognosis in Japanese Metastatic Urothelial Carcinoma: A Large Database Study on Enfortumab Vedotin in Metastatic Urothelial Carcinoma.

BACKGROUND: Enfortumab vedotin shows promise as a targeted therapy for advanced urothelial carcinoma, particularly in patients who have previously received platinum-based chemotherapy and an immune-checkpoint inhibitor. The EV-301 phase III trial demonstrated significantly improved overall survival and response rates compared to standard chemotherapy. However, more data, especially from larger real-world studies, are needed to further assess its effectiveness in Japanese patients. METHODS: A total of 6007 urothelial cancer patients inducted with pembrolizumab as a second-line treatment were analyzed. Among them, 563 patients received enfortumab vedotin after pembrolizumab, while 443 patients received docetaxel or paclitaxel after pembrolizumab, and all were included in the study for efficacy as a life prolonging agent. RESULTS: The enfortumab vedotin group showed a longer overall survival than the paclitaxel/docetaxel group (p = 0.013, HR: 0.71). In multivariate analysis, enfortumab vedotin induction was the independent risk factor for overall survival (p = 0.013, HR: 0.70). There were no significant differences in cancer-specific survival. CONCLUSIONS: Enfortumab vedotin prolonged the overall survival for Japanese advanced or metastatic urothelial carcinoma patients compared to paclitaxel or docetaxel after pembrolizumab treatment.

Predictive factors for pentafecta achievement in robot-assisted partial nephrectomy for intermediate highly complex RENAL tumors (RENAL score ≥ 7).

OBJECTIVES: To investigate the predictive factors for pentafecta achievement of robot-assisted partial nephrectomy (RAPN) for intermediate highly complex renal tumors (RENAL score ≥ 7). METHODS: We retrospectively analyzed the data of 247 patients with renal tumors with a RENAL score ≥ 7 who underwent RAPN. Baseline characteristics and perioperative outcomes were compared between the pentafecta achieved group and the unachieved group. A multivariable logistic regression model was used to identify the predictive factors for pentafecta achievement for cT1 renal tumors with a RENAL score ≥ 7. RESULTS: Of the 247 patients, 75 (30.3%) patients were in the achieved group and 172 (69.7%) patients were in the unachieved group. The median warm ischemia time and total operation time were 18 min versus 23 min (p < 0.001) and 179 min versus 201 min (p < 0.001) in the achieved and unachieved groups, respectively. In the unachieved group, six patients (3.4%) had major perioperative complications (Clavien-Dindo classification system ≥3). The median preservation rates of estimated GFR at the 1-year postoperative period were 96.5% versus 83.0% (p < 0.001) in the achieved and unachieved groups. Multivariable logistic regression models revealed that age and tumor size were independent predictive factors for pentafecta achievement for cT1 renal tumors with a RENAL score ≥ 7. There were no significant differences in cancer-free survival between the two groups (p = 0.456). CONCLUSION: Age and tumor size were independent predictive factors for pentafecta achievement, although there was no difference in oncological outcomes between the pentafecta achieved group and the unachieved group in RAPN for cT1 renal tumors with a RENAL score ≥ 7.

Revisiting the canonical definition of heat hematoma: A rare case of postmortem subdural heat hematoma.

Heat hematoma is generally recognized as a postmortem heat-induced artifact in extradural spaces found in burned bodies. Conversely, subdural hematoma in charred bodies is more indicative of antemortem trauma. Here, we present a rare case of a subdural heat hematoma in forensic practice. The subdural hematoma was found in a charred body that was determined to be dead before the fire without findings of antemortem head injury. Furthermore, the detailed determination and formation mechanism of this subdural heat hematoma are discussed. With this rare case, we propose a reconsideration of the canonical definition of heat hematoma. This report envisions benefitting forensic pathologists facing similar cases.

Cocaine induces vascular smooth muscle cells proliferation via DRP1-mediated mitochondrial fission and PI3K/HIF-1α signaling.

Long-term cocaine abuse is associated with cardiovascular and pulmonary vascular complications. The vascular toxicity of cocaine can lead to vascular remodeling characterized by excessive proliferation of vascular smooth muscle cells. Though hypoxia-inducible factor (HIF) signaling and mitochondrial fission have been suggested to play essential roles in the pathogenesis of hypoxia-induced vascular remodeling, pathogenetic mechanism for cocaine-related vascular remodeling remains to be elucidated. In this study, we explore the effect of cocaine on the proliferation of vascular smooth muscle cells by in vitro experiments. The findings indicated that the cocaine-induced vascular smooth muscle cell hyperproliferation is achieved by enhancing DRP1-mediated mitochondrial fission and activating PI3K/HIF-1α signaling. Current findings suggested that mitochondrial fission would play a pivotal role in cocaine-related vascular remodeling and would be helpful in understanding the vascular toxicity of cocaine.

Excessive N-acetylcysteine exaggerates glutathione redox homeostasis and apoptosis during acetaminophen exposure in Huh-7 human hepatoma cells.

Acetaminophen (APAP) hepatotoxicity is one of the biggest drawbacks of this relatively safe and widely used drug. In addition to its hepatotoxicity, APAP also cause comparable levels of toxicity on human hepatoma cells. Here we show activation of the intrinsic caspase-9/3 pathway of apoptosis followed by gasdermin E (GSDME) cleavage and subsequent ballooning in APAP (10 mM, 72 h)-treated Huh-7 human hepatocarcinoma cells. N-acetylcysteine (NAC), an antioxidant currently used as an antidote for APAP overdose, does not alleviate APAP toxicity in Huh-7 cells; NAC overdose (10 mM) rather aggravates APAP toxicity. NAC overdose not only aggravates cell death, but also decreases the cellular GSH/GSSG ratio, an indicator of redox homeostasis of glutathione. These results show for the first time that APAP-induced apoptosis in hepatoma cells is followed by secondary necrosis via the caspase-3/GSDME pathway. NAC overdose (10 mM) not only worsens the glutathione redox status, but also accelerates this pathway.

Case Report: Molecular autopsy underlie COVID-19-associated sudden, unexplained child mortality.

Herein, we report a child with COVID-19 and seemingly no underlying disease, who died suddenly. The autopsy revealed severe anemia and thrombocytopenia, splenomegaly, hypercytokinemia, and a rare ectopic congenital coronary origin. Immunohistochemical analysis demonstrated that the patient had acute lymphoblastic leukemia of the B-cell precursor phenotype (BCP-ALL). The complex cardiac and hematological abnormalities suggested the presence of an underlying disease; therefore, we performed whole-exome sequencing (WES). WES revealed a leucine-zipper-like transcription regulator 1 (LZTR1) variant, indicating Noonan syndrome (NS). Therefore, we concluded that the patient had underlying NS along with coronary artery malformation and that COVID-19 infection may have triggered the sudden cardiac death due to increased cardiac load caused by high fever and dehydration. In addition, multiple organ failure due to hypercytokinemia probably contributed to the patient's death. This case would be of interest to pathologists and pediatricians because of the limited number of NS patients with LZTR1 variants; the complex combination of an LZTR1 variant, BCP-ALL, and COVID-19; and a rare pattern of the anomalous origin of the coronary artery. Thus, we highlight the significance of molecular autopsy and the application of WES with conventional diagnostic methods.

[A Case of Long-Term Survival Following Multidisciplinary Therapy for Small Intestinal Metastasis of Bladder Cancer].

The patient was a 70-year-old man who underwent transurethral resection of a bladder tumor. The pathological diagnosis was urothelial carcinoma (UC) with sarcomatoid variant, ≧pT2. After neoadjuvant chemotherapy using gemcitabine and cisplatin (GC), radical cystectomy was performed. The histopathological diagnosis was no tumor remnant (ypT0ypN0). Seven months later, the patient underwent an emergency partial ileectomy for ileal occlusion, after sudden complaints of vomiting and abdominal pain and fullness. Postoperatively, two cycles of adjuvant GC chemotherapy were administered. Approximately 10 months after ileal metastasis, a mesenteric tumor appeared. After seven cycles of methotrexate/epirubicin/nedaplatin and 32 cycles of pembrolizumab therapy, the mesentery was resected. The pathological diagnosis was UC with sarcomatoid variant. No recurrence was noted for 2 years after resection of the mesentery.

Aristolochic acid induces an inflammatory response with prostaglandin E2 production and apoptosis in NRK-52E proximal tubular cells.

Aristolochic acid nephropathy (AAN) is a type of drug-induced nephropathy in which ingestion of aristolochic acid (AA) causes acute kidney injury, with progressive renal fibrosis and upper urothelial carcinoma. Although the pathological features of AAN have been reported to involve significant cell degeneration and loss in the proximal tubules, the details of the toxic mechanism in the acute phase of the disease remain unclear. This study investigates the cell death pathway and intracellular metabolic kinetics of AA exposure in rat NRK-52E proximal tubular cells. AA exposure induces dose- and time-dependent apoptotic cell death in NRK-52E cells. We examined the inflammatory response to further investigate the mechanism of AA-induced toxicity. AA exposure increased the gene expression of inflammatory cytokines IL-6 and TNF-α, suggesting that AA exposure induces inflammation. Furthermore, analysis of lipid mediators by LC-MS revealed increases in intra- and extra-cellular arachidonic acid and prostaglandin E2 (PGE2). To investigate the relationship between the AA-induced increase in PGE2 production and cell death, celecoxib, an inhibitor of cyclooxygenase-2 (COX-2), which is involved in the production of PGE2, was administered, and a marked inhibition of AA-induced cell death was observed. These results suggest that exposure to AA induces concentration- and time-dependent apoptosis in NRK-52E cells, which is attributed to inflammatory responses mediated by COX-2 and PGE2.

The proportion of false-positives in positive Seratec® prostate-specific antigen SemiQuant test results in postmortem screening for seminal fluid.

Prostate-specific antigen (PSA) tests are used in forensics to conduct rapid screening for semen in vaginal swab samples from alleged victims of sexual abuse. Although PSA membrane tests have been applied to autopsy specimens, no study has evaluated predictors of false-positive test results in relation to factors such as age, cause of death, postmortem interval, drugs, and alcohol. This study describes the results obtained with the Seratec® PSA SemiQuant Kit test in 283 deceased women, with or without a history of sexual assault. Overall, 18.4% (52/283) of the vaginal swab samples tested positive for PSA. However, 63.5% (33/52) of the PSA-positive vaginal swab samples had no sperm detected. The proportion of false-positives in positive PSA results was 94.4% in those aged over 60 years. Multivariate logistic regression for PSA-positive samples showed that the proportion of false-positives in positive PSA results increased with the age of the deceased. However, the cause of death, postmortem interval, and presence of drugs or alcohol in the blood or urine of the deceased did not affect the PSA determination. These results show that PSA membrane tests are relatively unreliable and can be misleading, especially when derived from vaginal swab samples of older women, obtained at autopsy. In forensic cases, positive PSA screening test results may have an impact on subsequent legal actions and criminal charges brought against the accused. These findings are important for both forensic pathologists and the police to ensure accurate screening of older women in cases of suspected sex crimes.

Induction of filamin-C and its involvement in the regulation of cellular senescence and apoptosis in Huh-7 hepatoma cells during arsenic trioxide exposure.

Arsenic trioxide (ATO) is one of the most toxic inorganic arsenic compounds. In this study, we examined the effects of long-term (7 days) exposure to low dose (5 µM) ATO on a human hepatocellular carcinoma cell line, Huh-7. Along with apoptosis accompanied by secondary necrosis though GSDME cleavage, we observed enlarged and flattened cells adhering to the culture dish and surviving even after exposure to ATO. An increase in cyclin-dependent kinase inhibitor p21 levels as well as positive staining for senescence-associated ß-galactosidase activity were observed in ATO-treated cells, indicating cellular senescence. Screening for both ATO-inducible proteins by MALDI-TOF-MS analysis and ATO-inducible genes by DNA microarray analysis showed a marked increase in filamin-C (FLNC), an actin cross-linking protein. Interestingly, the increase in FLNC was observed in both dead and surviving cells, suggesting that the upregulation of FLNC by ATO occurs in both apoptotic and senescent cells. Small interference RNA-mediated knock down of FLNC resulted in not only a reduction of senescence-associated enlarged morphology of the cells, but also an exacerbation of cell death. Taken together, these results suggest a regulatory role of FLNC in the execution of senescence as well as apoptosis during ATO exposure.