Clinical Efficacy and Safety of Low-Dose Pemafibrate in Patients With Severe Renal Impairment: A Retrospective Study.

BACKGROUND: The management of hypertriglyceridemia in patients with chronic kidney disease (CKD) is important. Pemafibrate, a novel selective peroxisome proliferator-activated receptor-alpha modulator with less toxic effects on liver and kidney function than those of other fibrates, has recently been approved for the treatment of patients with an estimated glomerular filtration rate (eGFR) lower than 30 mL/min/1.73 m2. However, the efficacy and safety of pemafibrate in patients with severe renal impairment have not yet been established. METHODS: This single-center, retrospective observational study included 12 outpatients with CKD and hypertriglyceridemia, who were newly started on low-dose pemafibrate (0.1 mg/day) treatment between December 2021 and May 2023 and whose eGFRs were less than 30 mL/min/1.73 m2 at baseline. Blood samples were collected before and at 12 weeks after pemafibrate treatment. RESULTS: After 12 weeks of treatment, the serum triglyceride level was significantly decreased, whereas the high-density lipoprotein cholesterol level was significantly increased. The serum alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transpeptidase, and uric acid levels were also significantly decreased, without worsening of the eGFR and serum creatinine levels. In the subgroup analysis, there were no significant differences in the changes in clinical parameters regardless of statin use and CKD stage at baseline. CONCLUSIONS: Low-dose pemafibrate administration in patients with severe renal impairment resulted in significant improvements in triglyceride, high-density lipoprotein cholesterol, and serum uric acid levels, and liver function, without adverse events.

Effects of switching from agalsidase-α to agalsidase-ß on biomarkers, renal and cardiac parameters, and disease severity in fabry disease forming neutralizing antidrug antibodies: a case report.

Fabry disease is an X-linked hereditary disorder caused by deficient α-galactosidase A (GLA) activity. Patients with Fabry disease are often treated with enzyme replacement therapy (ERT). However, ERT often induces the formation of neutralizing antidrug antibodies (ADAs), which may impair the therapeutic efficacy. Here, we report the case of a 32-year-old man with Fabry disease and resultant neutralizing ADAs who was treated by switching from agalsidase-α to agalsidase-ß. We monitored biomarkers, such as plasma globotriaosylsphingosine (lyso-Gb3), urinary globotriaosylceramide (Gb3), urinary mulberry bodies, renal and cardiac parameters, and disease severity during the treatment period. Although plasma lyso-Gb3 and urinary Gb3 levels quickly decreased within two months after the initiation of ERT with agalsidase-α, they gradually increased thereafter. The urinary mulberry bodies continued to appear. Both the ADA titer and serum mediated GLA inhibition rates started to increase after two months. Moreover, 3.5 years after ERT, the vacuolated podocyte area in the renal biopsy decreased slightly from 23.1 to 18.9%. However, plasma lyso-Gb3 levels increased, and urinary Gb3, mulberry body levels, and ADA titers remained high. Therefore, we switched to agalsidase-ß which reduced, but did not normalize, plasma lyso-Gb3 levels and stabilized renal and cardiac parameters. Disease severity was attenuated. However, urinary Gb3 and mulberry body levels did not decrease noticeably in the presence of high ADA titers. The kidneys take up a small amount of the administered recombinant enzyme, and the clearance of Gb3 that has accumulated in the kidney may be limited despite the switching from agalsidase-α to agalsidase-ß.

X-linked Alport Syndrome with Type IV Collagen α5 Chain Staining Revealing Normal Expression in the Glomerular Basement Membrane and Negative on Bowman's Capsule and Distal Tubular Basement Membrane: A Case Report.

X-linked Alport syndrome is a hereditary progressive renal disease resulting from the disruption of collagen α3α4α5 (IV) heterotrimerization caused by pathogenic variants in the COL4A5 gene. This study aimed to report a male case of X-linked Alport syndrome with a mild phenotype accompanied by an atypical expression pattern of type IV collagen α5 [α5 (IV)] chain in glomerulus. A 38-year-old male presented with proteinuria (2.3 g/day) and hematuria. He has been detected urinary protein and occult blood since childhood. A renal biopsy was performed at the age of 29 years; however, a diagnosis of Alport syndrome was not considered. A renal biopsy 9 years later revealed diffuse thinning and lamellation of the glomerular basement membrane. Α staining for α5 (IV) revealed a normal expression pattern in the glomerular basement membrane and a complete negative expression in Bowman's capsule and distal tubular basement membrane. Using next-generation sequencing, we detected a COL4A5 missense variant within exon 35 (NM_000495.5: c.3088G>A, p. G1030S). The possibility of X-linked Alport syndrome should be considered when negative expression of α5 (IV) staining on Bowman's capsule was observed.

Successful treatment of nephrotic syndrome due to pregnancy-related crescentic IgA nephropathy: a case report.

BACKGROUND: Crescentic immunoglobulin A (IgA) nephropathy, defined as > 50% of the glomeruli with crescents, often has a poor renal prognosis. Because of the high prevalence of pre-eclampsia in the second trimester of pregnancy, we often fail to investigate the new onset of glomerulonephritis and the aggravation of subclinical nephropathies. We report a case of nephrotic syndrome suggestive of crescentic IgA nephropathy possibly triggered by pregnancy. CASE PRESENTATION: A 33-year-old multipara was referred for persistent proteinuria, hematuria, and hypoalbuminemia two months postpartum. The patient was diagnosed with proteinuria for the first time at 36 weeks of gestation. The patient was normotensive during pregnancy. Renal biopsy revealed crescentic IgA nephropathy, with cellular crescents in 80% of the glomeruli and no global sclerosis. After treatment with pulse steroids followed by high-dose oral glucocorticoids and tonsillectomy, a gradual improvement was seen in proteinuria, hematuria, and hypoalbuminemia. CONCLUSION: Although the precise mechanism remains unclear, pregnancy possibly triggered the new onset of crescentic IgA nephropathy or the aggravation of subclinical IgA nephropathy.

Successful treatment with ivabradine in a ß-blocker-refractory patient with acute decompensated heart failure with reduced ejection fraction.

Ivabradine is an established treatment for chronic heart failure with reduced ejection fraction (HFrEF); however, it is not used for acute heart failure treatment. Negative inotropic effects (NIE) often limit the up-titration of ß-blockers. Contrarily, ivabradine has no NIE, and enables ß-blockers usage for treating patients with acute decompensated HFrEF.

Successful Treatment of Nephrotic Syndrome Due to Collapsing Focal Segmental Glomerulosclerosis Accompanied by Acute Interstitial Nephritis.

A 39-year-old woman was hospitalized for nephrotic syndrome. Laboratory test results showed increased serum creatinine levels and urinary excretions of beta-2-microglobulin, and N-acetyl-beta-D-glucosaminidase. A renal biopsy revealed collapsing focal segmental glomerulosclerosis (FSGS) and acute interstitial nephritis. Despite treatment with pulse steroid followed by oral high-dose glucocorticoids and cyclosporines, heavy proteinuria persisted. After low-density lipoprotein apheresis (LDL-A) therapy was initiated, her proteinuria gradually decreased, leading to complete remission. A repeat renal biopsy after treatment revealed no collapsing glomeruli. Immediate LDL-A should be performed to treat cases of collapsing FSGS poorly responding to other treatments.

Determining desire to live among patients with advanced hepatobiliary-pancreatic cancer for whom curative treatment is not indicated.

This study aimed to evaluate the desire to live among patients with advanced hepatobiliary-pancreatic cancer who were excluded from radical treatment and to examine the ideal nursing support for them. We recruited 18 patients in a department specializing in the treatment of hepatobiliary-pancreatic cancer at a university hospital in the metropolitan area of Japan. We included those with advanced hepatobiliary-pancreatic cancer who received a treatment other than definitive treatment. We conducted semi-structured interviews, and the responses were analyzed qualitatively and descriptively. Events experienced by patients with advanced hepatobiliary-pancreatic cancer and out of indication for radical treatment were divided into five major phases, while desire to live was divided into 11 categories. Two of these categories were represented by the word "death". The desire to live was present in all phases, and the expressions of these desires were diverse. Patients suppressed expressing their desire to live because they understood that their situation was challenging. In addition, there was a tendency to avoid expressing their desire to live to medical staff and their families. We found that nurses need to establish a medical relationship in which patients can express their desire to live and become connected to nursing support.

Splenic abscess diagnosed following relapsing sterile peritonitis in a peritoneal dialysis patient: A case report with literature review.

Peritoneal dialysis (PD)-related peritonitis is sometimes complicated with other infections; however, few cases of splenic abscess have been reported. We present the case of a 64-year-old PD patient with complicated splenic abscesses diagnosed following relapsing sterile peritonitis. After PD induction, he presented with turbid peritoneal fluid and was diagnosed with PD-related peritonitis. A plain abdominal computed tomography (CT) did not reveal any intra-abdominal focus of infection. After empiric intravenous antibiotics, the peritoneal dialysate was initially cleared, with a decrease in dialysate white blood cells (WBC) to 20/µL. However, WBC and C-reactive protein (CRP) levels remained elevated. A contrast-enhanced abdominal CT showed two areas of low-density fluid with no enhancement in a mildly enlarged spleen, making it difficult to distinguish abscesses from cysts. Due to relapsing sterile peritonitis, we performed an abdominal ultrasonography, and suspected splenic abscesses due to rapid increase in size. Repeated imaging tests were useful in establishing a diagnosis of splenic abscesses. Considering the persistent elevation of WBC and CRP levels, imaging findings, and episodes of relapsing peritonitis, we comprehensively formed the diagnosis, and performed a splenectomy as a rescue therapy. We should consider the possibility of other infectious foci with persistent inflammation after resolving PD-related peritonitis.

Parathyroidectomy for tertiary hyperparathyroidism after second kidney transplantation: a case report.

Successful kidney transplantation usually resolves secondary hyperparathyroidism (SHPT). However, some patients fail to normalize, and their condition is often referred to as tertiary hyperparathyroidism (THPT). Surgical consensus on the timing of post-transplant parathyroidectomy (PTX) for THPT has not been reached. Herein, we report a case of a 58-year-old post-transplant woman, considering the concrete timing of PTX for both SHPT and THPT. She initiated hemodialysis with end-stage renal disease at the age of 24, and underwent first kidney transplantation at the age of 28. When peritoneal dialysis (PD) was induced due to the worsening kidney function at the age of 50, the serum intact parathyroid hormone (iPTH) level remarkably increased (2332 pg/mL). Although cinacalcet was administered, the patient's iPTH levels were not sufficiently suppressed for seven years. Diagnostic images including ultrasound, computed tomography, and 99mTc-methoxyisobutylisonitrile scintigraphy indicated THPT as the reason for prolonged post-transplant hypercalcemia. Therefore, PTX was performed 14 months after the second transplantation. Histology showed nodular hyperplasia of all parathyroid glands, indicating autonomous secretion of parathyroid hormone. In general, patients with more severe THPT are recognized with more severe SHPT prior to transplantation during the dialysis period. We should consider a referral for surgery based on the individual risk factors. We recommend to perform parathyroidectomy earlier, before the kidney transplantation in the clinical suspicion of severe SHPT.

Pulmonary sarcoidosis as a cause of intermittent fever of unknown origin in a hemodialysis patient with renal cell carcinoma: A case report and literature review.

Hemodialysis patients have weakened immune systems and can exhibit fever due to various causes. Herein, we describe the case of a 61-year-old hemodialysis patient who exhibited intermittent low-grade fever after a pacemaker had been implanted 2 months before due to sick sinus syndrome. She had a medical history of subcutaneous sarcoidosis and uveitis. Active pulmonary sarcoidosis was diagnosed based on elevated soluble interleukin-2 receptor, elevated lysozyme level, and gallium-67 scintigraphy uptake in hilar and mediastinal lymph nodes. She was also diagnosed with renal cell carcinoma via contrast computed tomography. However, because her C-reactive protein level remained normal, the possibility of neoplastic fever was considered low. After the initiation of prednisolone administration, her fever gradually disappeared. Her serum soluble interleukin-2 receptor and lysozyme level improved in parallel with the enlargement of the mediastinal lymph node and gallium-67 scintigraphy uptake.

Alogliptin-Induced Minimal Change Nephrotic Syndrome and Interstitial Nephritis.

Alogliptin is one of the dipeptidyl peptidase-4 inhibitors used to treat patients with type 2 diabetes. Little is known about the nephrotoxicity associated with alogliptin, such as nephrotic syndrome or interstitial nephritis. We report a biopsy-proven rare case of minimal change nephrotic syndrome and interstitial nephritis induced by alogliptin. A 68-year-old man who had been prescribed alogliptin was hospitalized for nephrotic syndrome. On admission, serum creatinine level was elevated with increased urinary ß2-microglobulin and N-acetyl-ß-d-glucosaminidase excretion. Kidney biopsy revealed minor glomerular abnormalities and interstitial nephritis, and gallium-67 scintigraphy showed uptake in both kidneys. A drug lymphocyte stimulation test for alogliptin was positive. With discontinuation of alogliptin treatment alone, serum creatinine level normalized in parallel with urine ß2-microglobulin and N-acetyl-ß-d-glucosaminidase levels. In addition, complete remission of nephrotic syndrome was observed. Drug-induced dual pathology has not been previously reported with alogliptin. In summary, clinicians should keep in mind that alogliptin can induce minimal change nephrotic syndrome and interstitial nephritis.

Intraperitoneal neutrophils activated by KRAS-induced ovarian cancer exert antitumor effects by modulating adaptive immunity.

Increased neutrophil counts are a hallmark of a poor prognosis for cancer. We previously reported that KRAS promoted tumorigenesis and increased neutrophil counts in a mouse peritoneal cancer model. In the current study, we evaluated the role of increased neutrophils in cancer progression, as well as their influence on the intraperitoneal microenvironment. A mouse peritoneal cancer model was established using the KRAS-transduced mouse ovarian cancer cell line, ID8-KRAS. Neutrophil function was assessed by neutrophil depletion in ID8-KRAS mice. Neutrophil depletion markedly accelerated tumor formation; this was accompanied by an increase in interleukin-6 concentrations in ascites. Neutrophil depletion significantly decreased the amount of local and systemic CD8+ T cells, while increasing the amount of local CD4+ T cells, accompanied by an increased amount of monocytic myeloid-derived suppressor cells (M-MDSCs) and regulatory T cells (Tregs) (P<0.05). The roles of peritoneal neutrophils (PENs) in CD8+ T cell activation were assessed in vitro. PENs of ID8-KRAS mice had a strong potential to enhance T cell proliferation with a higher expression of the T cell costimulatory molecules OX40 ligand (OX40L) and 4-1BB ligand (4-1BBL), as compared with peripheral blood neutrophils (PBNs). These findings suggest that neutrophils recruited into the KRAS-induced tumor microenvironment (TME) have antitumor properties with the potential to modulate the numbers of M-MDSCs and Tregs and activate CD8+ T cells through T cell costimulatory molecules.

A case of primary extranodal natural killer/T-cell lymphoma in the orbit and intraocular tissues with cerebrospinal fluid involvement.

PURPOSE: To report a rare case of primary orbital natural killer (NK)/T-cell lymphoma without nasal lesions but with cerebrospinal fluid involvement. OBSERVATIONS: A 73-year-old woman was referred to the uveitis clinic with suspected unilateral acute uveitis in her right eye and a right orbital tumor. Epstein-Barr virus DNA was detected in the aqueous humor in her right eye, and orbital biopsy revealed the presence of extranodal NK/T-cell lymphoma (ENKTL), nasal type. Positron emission tomography showed significant 18F-fluorodeoxyglucose uptake in the right orbit, with no other signs of systemic involvement. Cerebrospinal fluid analysis demonstrated lymphoma cell infiltration. She was diagnosed with stage IV ENKTL and treated with orbital radiotherapy and systemic chemotherapy, with subsequent remission. However, the lymphoma relapsed in her left vitreous at 10 months after therapy, suggesting metastasis of lymphoma cells to the contralateral eye via the vitreous and cerebrospinal fluid. CONCLUSIONS AND IMPORTANCE: A few cases of ocular-tissue ENKTL have been reported, mostly involving invasion or dissemination of primary nasal lesions; in contrast, primary orbital and intraocular ENKTL has rarely been reported. To the best of our knowledge, this is the first report of a primary orbital ENKTL metastasizing to the vitreous of the contralateral eye. Although ENKTL is rare in the orbit and intraocular tissues, it should be considered as a possible differential diagnosis in patients with orbital tumors or intraocular inflammation resistant to steroid therapy because ENKTL has a very poor prognosis in the advanced stage.

Blood Vessel Invasion Is a Strong Predictor of Postoperative Recurrence in Endometrial Cancer.

OBJECTIVES: Although lymphovascular space invasion is a prognostic factor for the recurrence of resectable endometrial cancer, the differential impacts of lymphatic vessel invasion (LVI) and blood vessel invasion (BVI) on the recurrence of endometrial cancer are poorly described. We investigated the prognostic significance of LVI and BVI on the recurrence of endometrial cancer and their association with patterns of recurrence. METHODS: We retrospectively reviewed 376 patients with stage I to III endometrial cancer who underwent surgery with curative intent at our institution between 2007 and 2015. The associations of the presence of lymphovascular space invasion or LVI and BVI with recurrence-free survival and patterns of recurrence were evaluated. RESULTS: Lymphovascular space invasion positivity was an independent prognostic factor for recurrence-free survival (hazards ratio [HR], 3.070; 95% confidence interval [CI], 1.404-6.824; P = 0.0048). However, when categorized by LVI versus BVI, the latter was a strong independent prognostic factor (HR, 2.697; CI, 1.288-5.798; P = 0.0081), whereas the former was not (HR, 1.740; CI, 0.795-3.721; P = 0.1637). Hematogenous metastasis was the most prevalent form of recurrence in endometrial cancer (24 [50%] of all 48 recurrent cases). Notably, 17 (19.5%) of 87 patients with BVI developed hematogenous metastases, compared with 7 (2.4%) of 289 without BVI (χ test, P < 0.0001). CONCLUSIONS: Blood vessel invasion rather than LVI was a strong predictor of postoperative recurrence in stage I to III endometrial cancer, probably due to its predisposition to hematogenous metastases.

Therapeutic significance of targeting survivin in cervical cancer and possibility of combination therapy with TRAIL.

Loss of p53 function due to human papillomavirus (HPV) infection induces resistance to apoptosis in cervical cancer cells. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which induces apoptosis in a p53-independent manner, may provide an alternative strategy for treating cervical cancer. Survivin, an antiapoptotic protein that is highly expressed in cancer cells, regulates apoptosis and the cell cycle. Here, we investigated the therapeutic potential of targeting survivin, while focusing on the TRAIL-induced apoptosis pathway. The viability and cell cycle of HPV16-positive CaSki and SiHa cells were assessed after survivin knockdown by small interfering RNA (si-survivin). E-cadherin expression was also assessed after si-survivin treatment, using western blotting. SiHa (a TRAIL-resistant cell line) was used for further studies. The small molecule YM155 and resveratrol (RVT; a polyphenol with the potential to suppress survivin expression) were used as survivin inhibitors. The effects of si-survivin and survivin inhibitors on TRAIL- or cisplatin (CDDP)-induced apoptosis were analyzed by annexin-V staining. si-survivin treatment decreased cell viability and led to G2/M arrest, accompanied by morphological changes and E-cadherin upregulation in both CaSki and SiHa cells. si-survivin and YM155 synergistically sensitized TRAIL-resistant SiHa cells to TRAIL-induced apoptosis (p < 0.05). However, si-survivin and YM155 only slightly increased CDDP-induced apoptosis. RVT markedly enhanced TRAIL-induced apoptosis by suppressing survivin expression. Targeting of survivin expression might be an ideal strategy for cervical cancer treatment as it would decrease viable cell number and enhance apoptosis sensitivity. Further, combination therapy with TRAIL, rather than CDDP, may be compatible with the proposed survivin-targeting strategy.

Detachment from the primary site and suspension in ascites as the initial step in metabolic reprogramming and metastasis to the omentum in ovarian cancer.

Cancer cell metabolism is currently considered to be context dependent, and metabolic reprogramming is being widely investigated. It is known that ovarian cancer often metastasizes to the omentum. Given that the omentum itself contains a high concentration of adipocytes, ovarian cancer is thought to be a good model for research into metabolic reprogramming (particularly the shift to lipid metabolism). The present study investigated the switch to lipid metabolism in the metabolic reprogramming of ovarian cancer cells. The present study first considered the possibility of epigenetic involvement. Using an open database (GSE 85293 and GSE2109), the methylation status and gene expression patterns of the primary tumor site (ovary) and the metastatic tumor site (omentum) were compared. However, no evidence was obtained regarding the involvement of epigenetics (at least in terms of DNA methylation). The influence of suspension in ascites on metabolism was then considered, and a suspension culture was used as an in vitro model. It was demonstrated that ovarian cancer cells that are detached from the primary site and suspended in ascites have enhanced lipid metabolism. Additionally, it was demonstrated that these cells express high levels of the cancer stem cell (CSC) marker cluster of differentiation 44 and c-kit in a balanced manner as they approach the omentum. Accordingly, these cells activate the mammalian target of rapamycin pathway, which is thought to be advantageous for cancer cell metastasis. In conclusion, the present study proposed one explanation for why ovarian cancer cells are likely to disseminate to the peritoneal cavity, and in particular to the omentum.

Regeneration of cervical reserve cell-like cells from human induced pluripotent stem cells (iPSCs): A new approach to finding targets for cervical cancer stem cell treatment.

Cervical reserve cells are epithelial progenitor cells that are pathologically evident as the origin of cervical cancer. Thus, investigating the characteristics of cervical reserve cells could yield insight into the features of cervical cancer stem cells (CSCs). In this study, we established a method for the regeneration of cervical reserve cell-like properties from human induced pluripotent stem cells (iPSCs) and named these cells induced reserve cell-like cells (iRCs). Approximately 70% of iRCs were positive for the reserve cell markers p63, CK5 and CK8. iRCs also expressed the SC junction markers CK7, AGR2, CD63, MMP7 and GDA. While iRCs expressed neither ERα nor ERß, they expressed CA125. These data indicated that iRCs possessed characteristics of cervical epithelial progenitor cells. iRCs secreted higher levels of several inflammatory cytokines such as macrophage migration inhibitory factor (MIF), soluble intercellular adhesion molecule 1 (sICAM-1) and C-X-C motif ligand 10 (CXCL-10) compared with normal cervical epithelial cells. iRCs also expressed human leukocyte antigen-G (HLA-G), which is an important cell-surface antigen for immune tolerance and carcinogenesis. Together with the fact that cervical CSCs can originate from reserve cells, our data suggested that iRCs were potent immune modulators that might favor cervical cancer cell survival. In conclusion, by generating reserve cell-like properties from iPSCs, we provide a new approach that may yield new insight into cervical cancer stem cells and help find new oncogenic targets.

Intracellular signaling entropy can be a biomarker for predicting the development of cervical intraepithelial neoplasia.

While the mortality rates for cervical cancer have been drastically reduced after the introduction of the Pap smear test, it still is one of the leading causes of death in women worldwide. Additionally, studies that appropriately evaluate the risk of developing cervical lesions are needed. Therefore, we investigated whether intracellular signaling entropy, which is measured with microarray data, could be useful for predicting the risks of developing cervical lesions. We used three datasets, GSE63514 (histology), GSE27678 (cytology) and GSE75132 (cytology, a prospective study). From the data in GSE63514, the entropy rate was significantly increased with disease progression (normal < cervical intraepithelial neoplasia, CIN < cancer) (Kruskal-Wallis test, p < 0.0001). From the data in GSE27678, similar results (normal < low-grade squamous intraepithelial lesions, LSILs < high-grade squamous intraepithelial lesions, HSILs ≤ cancer) were obtained (Kruskal-Wallis test, p < 0.001). From the data in GSE75132, the entropy rate tended to be higher in the HPV-persistent groups than the HPV-negative group. The group that was destined to progress to CIN 3 or higher had a tendency to have a higher entropy rate than the HPV16-positive without progression group. In conclusion, signaling entropy was suggested to be different for different lesion statuses and could be a useful biomarker for predicting the development of cervical intraepithelial neoplasia.

Targeting glutamine metabolism and the focal adhesion kinase additively inhibits the mammalian target of the rapamycin pathway in spheroid cancer stem-like properties of ovarian clear cell carcinoma in vitro.

Ovarian cancer is one of the leading causes of death in the world, which is linked to its resistance to chemotherapy. Strategies to overcome chemoresistance have been keenly investigated. Culturing cancer cells in suspension, which results in formation of spheroids, is a more accurate reflection of clinical cancer behavior in vitro than conventional adherent cultures. By performing RNA-seq analysis, we found that the focal adhesion pathway was essential in spheroids. The phosphorylation of focal adhesion kinase (FAK) was increased in spheroids compared to adherent cells, and inhibition of FAK in spheroids resulted in inhibition of the downstream mammalian target of the rapamycin (mTOR) pathway in ovarian clear cell carcinomas. This result also suggested that only using a FAK inhibitor might have limitations because the phosphorylation level of FAK could not be reduced to the level in adherent cells, and it appeared that some combination therapies might be necessary. We previously reported that glutamine and glutamate concentrations were higher in spheroids than adherent cells, and we investigated a synergistic effect targeting glutamine metabolism with FAK inhibition on the mTOR pathway. The combination of AOA, a pan-transaminase inhibitor, and PF 573228, a FAK inhibitor, additively inhibited the mTOR pathway in spheroids from ovarian clear cell carcinomas. Our in vitro study proposed a rationale for the positive and negative effects of using FAK inhibitors in ovarian clear cell carcinomas and suggested that targeting glutamine metabolism could overcome the limitation of FAK inhibitors by additively inhibiting the mTOR pathway.

Low uptake of fluorodeoxyglucose in positron emission tomography/computed tomography in ovarian clear cell carcinoma may reflect glutaminolysis of its cancer stem cell-like properties.

The characteristics of ovarian cancers that showed low activation of glycolysis were investigated. Using medical records of patients with ovarian cancers who had undergone fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) prior to their primary surgery at the University of Tokyo Hospital between 2010 and 2015, we identified cases with a low uptake of FDG in PET/CT. We considered the maximum standardized uptake value (SUVmax) as the degree of glucose uptake. We investigated the properties which may account for the low activation of glycolysis in vitro. The expression level of alanine, serine, cysteine-preferring transporter 2 (ASCT2, a glutamine influx transporter), system L-type amino acid transporter 1 (LAT1, a glutamine efflux transporter) and glucose transporter 1 (GLUT1, a glucose influx transporter) were investigated by western blotting. The phosphorylation level of AMP-activated protein kinase (AMPK), which is one of the metabolic sensors, was also investigated. Most of the cases with a low uptake SUVmax were limited to patients with ovarian clear cell carcinoma (CCC). We obtained cancer stem cell (CSC)-like properties from CCC cell lines, and compared the expression levels of transporters between non-CSCs and CSCs. Whereas the expression level of ASCT2 was nearly unchanged between non-CSCs and CSCs, the expression levels of LAT1 and GLUT1 were decreased in CSCs compared to non-CSCs. The phosphorylation level of AMPK was reduced in CSCs compared to non-CSCs. In conclusion, we suggested that ovarian CCC showed low activation of glycolysis, and this may reflect glutaminolysis of its CSC-like properties.