Immunohistochemical Evaluation of Schlafen 11 (SLFN11) Expression in Cancer in the Search of Biomarker-Informed Treatment Targets: A Study of 127 Entities Represented by 6658 Tumors.

Schlafen 11 (SLFN11), a DNA/RNA helicase, acts as a regulator of cellular response to replicative stress and irreversibly triggers replication block and cell death. Several preclinical in vitro studies and clinical trials established that SLFN11 expression predicts outcomes in patients with advanced cancer treated with DNA-damaging chemotherapeutics and more recently with poly(ADP-ribose) polymerase inhibitors. SLFN11 expression status remains unknown in many cancer types, especially in mesenchymal tumors. This study evaluated a cohort of well characterized 3808 epithelial and 2850 mesenchymal and neuroectodermal tumors for SLFN11 expression using immunohistochemistry. Nuclear SLFN11 expression was rare in some of the most common carcinomas, for example, hepatocellular (1%), prostatic (2%), colorectal (5%), or breast (16%) cancers. In contrast, other epithelial tumors including mesotheliomas (92%), clear cell renal cell carcinomas (79%), small cell lung cancers (76%), squamous cell carcinomas of the tonsil (89%) and larynx (71%), or ovarian serous carcinomas (69%) were mostly SLFN11-positive. Compared with epithelial malignancies, SLFN11 expression was overall higher in neuroectodermal and mesenchymal tumors. Most positive entities included desmoplastic small round cell tumor (100%), Ewing sarcoma (92%), undifferentiated sarcoma (92%), solitary fibrous tumor (91%), dedifferentiated liposarcoma (89%), synovial sarcoma (86%), and malignant peripheral nerve sheath tumor (85%). Also, this study identifies tumors with potentially worse response to DNA-damaging drugs including antibody drug conjugates due to the absence of SLFN11 expression. Such entities may benefit from alternative treatments or strategies to overcome SLFN11 deficiency-related drug resistance. Our approach and results should serve as a foundation for future biomarker-associated clinical trials.

Acetalax (Oxyphenisatin Acetate, NSC 59687) and Bisacodyl Cause Oncosis in Triple-Negative Breast Cancer Cell Lines by Poisoning the Ion Exchange Membrane Protein TRPM4.

Triple-negative breast cancer (TNBC) is clinically aggressive and relatively unresponsive to current therapies. Therefore, the development of new anticancer agents is needed to satisfy clinical needs. Oxyphenisatin acetate (Acetalax), which had been used as a laxative, has recently been reported to have anticancer activity in murine models. In this study, we demonstrate that Acetalax and its diphenolic laxative structural analogue bisacodyl (Dulcolax) exhibit potent antiproliferative activity in TNBC cell lines and cause oncosis, a nonapoptotic cell death characterized by cellular and nuclear swelling and cell membrane blebbing, leading to mitochondrial dysfunction, ATP depletion, and enhanced immune and inflammatory responses. Mechanistically, we provide evidence that transient receptor potential melastatin member 4 (TRPM4) is poisoned by Acetalax and bisacodyl in MDA-MB468, BT549, and HS578T TNBC cells. MDA-MB231 and MDA-MB436 TNBC cells without endogenous TRPM4 expression as well as TRPM4-knockout TNBC cells were found to be Acetalax- and bisacodyl-resistant. Conversely, ectopic expression of TRPM4 sensitized MDA-MB231 and MDA-MB436 cells to Acetalax. TRPM4 was also lost in cells with acquired Acetalax resistance. Moreover, TRPM4 is rapidly degraded by the ubiquitin-proteasome system upon acute exposure to Acetalax and bisacodyl. Together, these results demonstrate that TRPM4 is a previously unknown target of Acetalax and bisacodyl and that TRPM4 expression in cancer cells is a predictor of Acetalax and bisacodyl efficacy and could be used for the clinical development of these drugs as anticancer agents. SIGNIFICANCE: Acetalax and bisacodyl kill cancer cells by causing oncosis following poisoning of the plasma membrane sodium transporter TRPM4 and represent a new therapeutic approach for TNBC.

The Novel ATR Inhibitor M1774 Induces Replication Protein Overexpression and Broad Synergy with DNA-targeted Anticancer Drugs.

Ataxia telangiectasia and Rad3-related (ATR) checkpoint kinase inhibitors are in clinical trials. Here we explored the molecular pharmacology and therapeutic combination strategies of the oral ATR inhibitor M1774 (Tuvusertib) with DNA-damaging agents (DDA). As single agent, M1774 suppressed cancer cell viability at nanomolar concentrations, showing greater activity than ceralasertib and berzosertib, but less potency than gartisertib and elimusertib in the small cell lung cancer H146, H82, and DMS114 cell lines. M1774 also efficiently blocked the activation of the ATR-CHK1 checkpoint pathway caused by replication stress induced by TOP1 inhibitors. Combination with non-toxic dose of M1774 enhanced TOP1 inhibitor-induced cancer cell death by enabling unscheduled replication upon replicative damage, thereby increasing genome instability. Tandem mass tag-based quantitative proteomics uncovered that M1774, in the presence of DDA, forces the expression of proteins activating replication (CDC45) and G2-M progression (PLK1 and CCNB1). In particular, the fork protection complex proteins (TIMELESS and TIPIN) were enriched. Low dose of M1774 was found highly synergistic with a broad spectrum of clinical DDAs including TOP1 inhibitors (SN-38/irinotecan, topotecan, exatecan, and exatecan), the TOP2 inhibitor etoposide, cisplatin, the RNA polymerase II inhibitor lurbinectedin, and the PARP inhibitor talazoparib in various models including cancer cell lines, patient-derived organoids, and mouse xenograft models. Furthermore, we demonstrate that M1774 reverses chemoresistance to anticancer DDAs in cancer cells lacking SLFN11 expression, suggesting that SLFN11 can be utilized for patient selection in upcoming clinical trials.

Protocadherin B9 Is Associated with Human Esophageal Squamous Cell Carcinoma Progression.

INTRODUCTION: Esophageal cancer is the sixth leading cause of cancer-related death worldwide. However, molecular targeted therapy and novel therapeutic targets are needed for esophageal squamous cell cancer (ESCC). In a previous study, we reported that protocadherin (PCDH) B9 plays an important role in several cancers. Therefore, in this study, we examined the clinical significance of PCDHB9 expression in ESCC. METHODS: PCDHB9 expression was examined using immunohistochemistry in 128 cases and using quantitative reverse transcription-polymerase chain reaction in 16 cases of ESCC. PCDHB9 function in ESCC cells was examined using RNA interference. RESULTS: High PCDHB9 expression was identified in 5 of 16 (31.3%). In total, 51 (40%) ESCC cases showed strong PCDHB9 expression, whereas nonneoplastic mucosa rarely showed its expression. High PCDHB9 expression was significantly associated with T classification, N grade, and stage in ESCC. In ESCC cell lines, PCDHB9 knockdown affected cell growth, migration, and adhesion. Further, the expression of integrin (ITG) A3, ITGA4, ITGA5, ITGB1, ITGB6, vimentin, snail family transcriptional repressor 1, and cadherin 2 (NCAD) was significantly reduced and cadherin 1 was significantly increased in PCDHB9 knockdown ESCC cells. CONCLUSION: These results suggest that PCDHB9 plays a tumor-promoting role and is a potential biomarker and therapeutic target in ESCC.

Essential Roles of TDO2 in Gastric Cancer: TDO2 Is Associated with Cancer Progression, Patient Survival, PD-L1 Expression, and Cancer Stem Cells.

INTRODUCTION: Tryptophan metabolism has been shown to be involved in tumor development. Two main tryptophan-degrading enzymes, tryptophan 2,3-dioxygenase (TDO2) and indoleamine 2,3-dioxygenase 1 (IDO1), may potently promote cancer cell survival and distant metastasis in diverse types of cancer, such as lung and breast cancer. IDO1 overexpression is an independent prognosticator in gastric cancer (GC). This work aimed to uncover the expression of TDO2 and its clinicopathologic significance in GC. METHODS: TDO2 expression was evaluated in public data of The Cancer Genome Atlas cohort STAD and in two different GC cohorts. Correlation between TDO2 and immune cell infiltrates as well as PD-L1 tumor staining was investigated. The biofunction of TDO2 was examined with MTT, colony formation, and spheroid formation assays by RNA interference. RESULTS: TDO2 expression was correlated with both progressive disease and clinical outcome, and its expression was an independent predictor of prognosis in GC. TDO2 expression was correlated with infiltration of immune cells and tumor expression of PD-L1. Inhibition of TDO2 expression suppressed cell proliferation, colony formation, and cell invasion of GC cells. Additionally, suppression of TDO2 expression inhibited spheroid body-formation and viability of GC organoids. CONCLUSION: Our data show that TDO2 might be a crucial marker for predicting prognosis and targeted therapy in GC.

Sarcomatoid variant of urothelial carcinoma of renal pelvis with direct invasion of the pancreas and descending colon.

Introduction: Sarcomatoid variant of urothelial carcinoma infiltrates the perimeter and occurs occasionally. However, there are only few case reports. Case presentation: A left renal tumor was incidentally detected in a 75-year-old woman and protruded outside the kidney, infiltrating the pancreatic tail and spleen. Tumor invasion was observed in the adjacent organs; therefore, the left kidney, pancreatic tail, spleen, and, descending colon were resected. Histopathological examination revealed a sarcomatoid variant of invasive urothelial carcinoma. She received two cycles of gemcitabine and carboplatin combination chemotherapy but succumbed to the disease after 5 months. Conclusion: Sarcomatoid variant of urothelial carcinoma is rare, with aggressive malignancy. The diagnosis was difficult and required surgery. This is the first case of a sarcomatoid variant of urothelial carcinoma with direct invasion into the pancreas and descending colon.

Protocadherin B9 Is Associated with Tumorigenesis and Cancer Progression in Colorectal Cancer.

BACKGROUND: Genes encoding transmembrane proteins expressed specifically in cancer cells may be ideal therapeutic targets or biomarkers for diagnosis. METHODS: In the present study, we investigated the expression and function of PCDHB9, which encodes transmembrane protein protocadherin B9 in colorectal cancer (CRC). RESULTS: Immunohistochemical analysis showed that 39 (26%) of 148 CRC cases were positive for protocadherin B9. Expression of protocadherin B9 correlated with lymphatic invasion, venous invasion, and T classification and was weakly detected in adenomas by immunohistochemistry. Although PCDHB9 knockdown did not change cell growth and invasion activity in CRC cell lines, cell adhesion to fibronectin was significantly reduced by PCDHB9 knockdown. Expressions of ITGA3, ITGA4, ITGA5, ITGB1, and ITGB6 were significantly reduced by PCDHB9 knockdown. In addition, the number of spheres was significantly decreased by PCDHB9 knockdown. CONCLUSION: These results suggest that protocadherin B9 might be associated with colorectal tumorigenesis and cancer progression in CRC.

Lymphangitis carcinomatosa from gallbladder cancer.

A 61-year-old woman was admitted to our hospital with productive cough and fever. Computed tomography images revealed ground glass opacities in both lung fields, and a space-occupying lesion in the gallbladder. Transbronchial lung biopsy revealed a poorly differentiated adenocarcinoma with invasion of the lymph ducts; accordingly, a diagnosis of lymphangitis carcinomatosa was made. We could not administer chemotherapy due to poor performance status, and the patient died of respiratory failure 30 days after admission. Owing to pathological autopsy findings of poorly differentiated adenocarcinoma in the gallbladder, we diagnosed this as a rare case of gallbladder cancer presenting with lymphangitis carcinomatosa.

Overexpression of aldolase, fructose-bisphosphate C and its association with spheroid formation in colorectal cancer.

Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide. The spheroid colony formation assay is a useful method to identify cancer stem cells (CSCs). Using the DLD-1 and WiDr CRC cell lines, we performed microarray analyses of spheroid body-forming and parental cells and demonstrated that aldolase, fructose-bisphosphate C (ALDOC) was overexpressed in the spheroid body-forming cells of both lines. Cells transfected with small interfering RNA against ALDOC demonstrated lower proliferation, migration, and invasion compared with negative control cells. Both the number and size of spheres produced by the CRC cells were significantly reduced by ALDOC knockdown. Additionally, inhibition of ALDOC reduced lactate production. Immunohistochemistry was used to analyze ALDOC protein expression in tissues from 135 CRC patients and revealed that 66 (49%) cases were positive for ALDOC. The ALDOC-positive cases were associated with higher T and M grades and, as determined by Kaplan-Meier analysis, a poorer prognosis. Univariate and multivariate analyses indicated that ALDOC expression was an independent prognostic factor for CRC patients. Furthermore, ALDOC expression was associated with CD44 expression. These results suggest that ALDOC contributes to CRC progression and plays an important role in CSCs derived from CRC.

A chronic encapsulated expanding hematoma that developed 15 years after gamma knife surgery for a cerebral arteriovenous malformation: A case report and review of the literature.

We report a case of gamma knife surgery (GKS)-induced chronic encapsulated expanding hematoma with extensive literature review. A 17-year-old young man underwent GKS after embolization for arteriovenous malformation (AVM) in the right frontal lobe and the AVM completely disappeared. He developed a generalized convulsion 15 years after GKS. MRI showed a small oedematous change at the AVM site. His epileptic seizure was controlled with anticonvulsant. His epilepsy recurred after three years, and MRI revealed an intracerebral hematoma with extensive surrounding edema at the same lesion. He underwent cerebral angiography and a recurrence of AVM was prevented. The hematoma was surgically removed, and intraoperative finding confirmed an old hematoma with a capsule and capillary hyperplasia, without developing cavernous angioma. The final diagnosis was a secondary chronic encapsulated expanding hematoma after GKS. This is the first report to show the early-stage imaging findings of this late effect after GKS.

Schlafen family member 11 indicates favorable prognosis of patients with head and neck cancer following platinum-based chemoradiotherapy.

Recently, Schlafen family member 11 (SLFN11) has been reported to increase the sensitivity of cancer cells to DNA-damaging agents, including platinum derivatives; thus, SLFN11 may be a predictive biomarker for platinum-based chemoradiotherapy (CRT). In this study, we examined whether SLFN11 expression was associated with the therapeutic outcome of platinum-based CRT in head and neck squamous cell carcinoma (HNSCC). We performed immunohistochemical analyses for SLFN11 expression in 161 HNSCC tissues from patients who had been administered cisplatin-based CRT and examined the correlation between SLFN11 expression and progression-free survival (PFS). Additionally, SLFN11 expression was examined in 10 paired samples obtained before and after CRT in patients with local failure. Furthermore, in vitro experiments were performed using several HNSCC cell lines and isogenic SLFN11-knockout cells to assess the association between SLFN11 expression and drug sensitivity. PFS was found to be significantly better in the SLFN11-positive group than in the SLFN11-negative group among the 161 patients (5-year PFS: 78.8% vs. 52.8%, respectively, p < 0.001). Similar results were observed for the PFS at each primary site. The percentage of SLFN11 positivity was lower in tumor samples from patients with local failure after CRT than that in the corresponding primary tumors before CRT in 8 of 10 cases. Results of the in vitro assay demonstrated that SLFN11-knockout cells exhibited reduced sensitivity to DNA-damaging agents but not to the non-DNA-damaging agent docetaxel. Our findings suggest that SLFN11 may serve as a potential biomarker for predicting the response of HNSCC patients to platinum-based CRT.

Cytological and histological findings of upper tract mucinous urothelial carcinoma with clear cell component: A case report and review of literature.

Mucinous urothelial carcinoma (UC) is a rare variant and only 18 cases of mucinous UC have been reported. In this article, we report a case of mucinous UC focusing on both cytological and histological findings. A 92-year-old female was referred to our hospital because of gross hematuria. Clinical computed tomography scan showed 2.2-cm papillary lesion in the lower part of the left ureter. Urine cytology was performed, and cytopathological findings showed that there were a few atypical cells with pale to clear cytoplasm, and a low amount of mucin in the background was identified by periodic acid-schiff (PAS) and alcian blue (AB) staining. Laparoscopic radical nephrectomy of left renal pelvis and ureter was performed. The gross examination revealed that a white-gray, papillary-sessile tumor was found in the lower part of the left ureter. Histologically, conventional high grade UC cells were seen in some areas, and tumor cells in other areas showed abundant clear cytoplasm with extracellular and intracytoplasmic mucin. Immunohistochemical analysis revealed that tumor cells were positive for CK7, CK20, p63, GATA3, MUC1, MUC2, and MUC5AC and negative for MUC6 and CDX2. Histopathological diagnosis was mucinous UC with clear cell component, and the pathological stage was pT1N0M0. The patient has remained well and disease-free for 3 months after the operation. Familiarity and recognizing the characteristic pathological findings of mucinous UC are important because it represents a malignant neoplasm.

Concordance of the histological diagnosis of type 1 autoimmune pancreatitis and its distinction from pancreatic ductal adenocarcinoma with endoscopic ultrasound-guided fine needle biopsy specimens: an interobserver agreement study.

The histological diagnosis of type 1 autoimmune pancreatitis (AIP) based on the findings obtained by an endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) is feasible, but the diagnostic consistency of this method has not been confirmed. We determined the interobserver agreement among 20 pathologists regarding the diagnosis of type 1 AIP, including the distinction from pancreatic ductal adenocarcinoma (PDAC) using large tissue samples obtained by EUS-FNB. After guidance for diagnosing AIP with biopsy tissues was provided, a round 2 was performed. The median sensitivity and specificity for diagnosing PDAC vs. non-neoplastic diseases were 95.2% and 100%, respectively. In groups of specialists (n = 7) and the generalists (n = 13), Fleiss' к-values increased from 0.886 to 0.958 and from 0.750 to 0.816 in round 2. The concordance was fair or moderate for obliterative phlebitis and storiform fibrosis but slight for ductal lesion of type 1 AIP. Discordant results were due to ambiguous findings and biopsy tissue limitations. Among the specialists, the ratio of cases with perfect agreement regarding the presence of storiform fibrosis increased in round 2, but agreement regarding obliterative phlebitis or ductal lesions was not improved. Although the histological definite diagnosis of type 1 AIP was achieved by most observers in > 60% of the cases, the confidence levels varied. Because some ambiguities exist, the histological diagnostic levels based on the diagnostic criteria of type 1 AIP should not be taken for granted. Guidance is effective for improving accurate PDAC diagnoses (notably by recognizing acinar-ductal metaplasia) and for evaluating storiform fibrosis.

Prognostic impact of Schlafen 11 in bladder cancer patients treated with platinum-based chemotherapy.

The utility of Schlafen 11 (SLFN11) expression as a predictive biomarker for platinum-based chemotherapy has been established for cancers from different histologies. However, the therapeutic relevance of SLFN11 in bladder cancer (BC) is unknown. Here, we examined the clinicopathologic significance of SLFN11 expression across 120 BC cases by immunohistochemistry. We divided the cases into two cohorts, one including 50 patients who received adjuvant or neoadjuvant platinum-based chemotherapy, and the other including 70 BC patients treated by surgical resection without chemotherapy. In the cohort of 50 BC cases treated with platinum-based chemotherapy, the SLFN11-positive group (n = 25) showed significantly better overall survival than the SLFN11-negative group (n = 25, P = .012). Schlafen 11 expression correlated significantly with the expression of luminal subtype marker GATA3. Multivariate analyses identified SLFN11 expression as an independent prognostic predictor (odds ratio, 0.32; 95% confidence interval, 0.11-0.91; P = .033). Conversely, in the cohort of 70 BC cases not receiving platinum-based chemotherapy, the SLFN11-positive group (n = 29) showed significantly worse overall survival than the SLFN11-negative group (n = 41, P = .034). In vitro analyses using multiple BC cell lines confirmed that SLFN11 KO rendered cells resistant to cisplatin. The epigenetic modifying drugs 5-azacytidine and entinostat restored SLFN11 expression and resensitized cells to cisplatin and carboplatin in SLFN11-negative BC cell lines. We conclude that SLFN11 is a predictive biomarker for BC patients who undergo platinum-based chemotherapy and that the combination of epigenetic modifiers could rescue refractory BC patients to platinum derivatives by reactivating SLFN11 expression.

CD44 Is Involved in Sunitinib Resistance and Poor Progression-free Survival After Sunitinib Treatment of Renal Cell Carcinoma.

BACKGROUND/AIM: Sunitinib continues to be administered as a first-line therapeutic agent in metastatic renal cell carcinoma (mRCC). This study aimed to examine the role of CD44 in sunitinib resistance and as a predictive marker in mRCC. MATERIALS AND METHODS: We analyzed the effect of CD44 knockdown on sunitinib resistance in RCC cell lines using WST-1 assays. CD44 expression in mRCC patients treated with first-line sunitinib was determined by immunohistochemistry. We validated the findings of this study by in silico analysis. RESULTS: CD44 knockdown increased sensitivity to sunitinib. Immunohistochemical analysis revealed that 19 (34.5%) of 55 mRCC cases were positive for CD44. CD44-positive cases were associated with poor progression-free survival (PFS) after first-line sunitinib treatment. In the JAVELIN 101 study, high CD44 expression was significantly associated with poor PFS after sunitinib but not after avelumab + axitinib therapy. CONCLUSION: CD44 is involved in sunitinib resistance and may be a promising marker for sunitinib treatment in mRCC.

Rotational Medicine Ball Throw Velocity Relates to NCAA Division III College Baseball Player Bat Swing, Batted Baseball, and Pitching Velocity.

ABSTRACT: Taniyama, D, Matsuno, J, Yoshida, K, Pyle, B, and Nyland, J. Rotational medicine ball throw velocity relates to NCAA Division III college baseball player bat swing, batted baseball, and pitching velocity. J Strength Cond Res 35(12): 3414-3419, 2021-Previous studies have evaluated relationships between baseball batting or pitching and whole-body power tests such as rotational medicine ball throw velocity (RMBTV) (transverse plane), lateral-to-medial hop for distance (frontal plane), and two-legged standing broad jump for distance (sagittal plane). However, no previous report has evaluated all 3 whole-body power tests in the same study to determine their relationship to bat swing velocity or pitching velocity. The purpose of this descriptive study was to determine correlational relationship strength between bat swing velocity, batted baseball velocity, and throwing velocity with 2-legged standing broad jump for distance, lateral-to-medial jump for distance, and RMBTV whole-body power tests in collegiate baseball players. Thirty-five NCAA Division III players (15 pitchers and 23 hitters; 3 players played pitcher and other positions) participated in this study. An alpha value of p < 0.05 was selected to indicate statistical significance. Moderate relationships were observed between bat swing velocity and RMBTV (r = 0.65, p = 0.003), explaining 39% of the variance, and between pitching velocity and RMBTV (r = 0.62, p = 0.02), explaining 38% of the variance. A moderate correlation was also observed between batted baseball velocity and RMBTV (r = 0.53, p = 0.02), explaining 28% of the variance. Only the RMBTV whole-body power test displayed significant relationships with bat swing velocity, batted baseball velocity, and pitching velocity. Significant relationships were not identified for either the two-legged standing broad jump for distance or the lateral-to-medial jump for distance whole-body power tests and bat swing velocity or pitching velocity. Further studies should evaluate whether the coordination developed during RMBTV movements can decrease baseball shoulder and elbow injuries associated with repetitive, poorly timed, sequential lower extremity-trunk-upper extremity whole-body movements.

P53 Is Involved in Sunitinib Resistance and Poor Progression-free Survival After Sunitinib Treatment of Renal Cell Carcinoma.

BACKGROUND/AIM: Sunitinib continues to be administered as a first-line therapeutic agent in metastatic renal cell carcinoma (mRCC). This study examined the potential role of p53 in sunitinib resistance and as a predictive marker in mRCC. MATERIALS AND METHODS: We analysed the effects of p53 knockout on sunitinib resistance. p53 expression in 53 mRCC patients receiving first-line sunitinib was determined immunohistochemically. We performed in silico analysis to examine the predictive value of p53 in mRCC. RESULTS: WST-1 assays showed that p53 knockout decreased sensitivity to sunitinib. Sunitinib and nutlin-3 together suppressed cell growth. Immunohistochemistry revealed 11 p53-positive cases among 53 patients with mRCC. Kaplan-Meier analysis showed that p53-positive cases tended to be associated with poor progression-free survival (PFS) after first-line sunitinib treatment. In the JAVELIN 101 study, TP53 mutation was significantly associated with poor PFS after sunitinib treatment. CONCLUSION: p53 may be involved in sunitinib resistance and represent a valuable marker for sunitinib treatment in mRCC.

Overexpression of claspin promotes docetaxel resistance and is associated with prostate-specific antigen recurrence in prostate cancer.

Although docetaxel (DTX) confers significant survival benefits in patients with castration-resistant prostate cancer (CRPC), resistance to DTX inevitably occurs. Therefore, clarifying the mechanisms of DTX resistance may improve survival in patients with CRPC. Claspin plays a pivotal role in DNA replication stress and damage responses and is an essential regulator for the S-phase checkpoint. CLSPN is an oncogenic gene that contributes to tumor proliferation in several human solid tumors. However, the clinical significance of claspin in prostate cancer (PCa) has not been examined. The present study aimed to elucidate the role of claspin and its relationship with DTX resistance in PCa. We immunohistochemically analyzed the expression of claspin in 89 PCa cases, of which 31 (35%) were positive for claspin. Claspin-positive cases were associated with higher Gleason score, venous invasion, and perineural invasion. Kaplan-Meier analysis showed that high claspin expression was related to poor prostate-specific antigen (PSA) relapse-free prognosis. In a public database, high CLSPN expression was associated with poor PSA relapse-free prognosis, Gleason score, T stage, lymph node metastasis, CRPC, and metastatic PCa. Claspin knockdown by siRNA decreased cell proliferation, upregulated DTX sensitivity, and suppressed the expression of Akt, Erk1/2, and CHK1 phosphorylation in DU145 and PC3 cell lines. Furthermore, claspin expression was much more upregulated in DTX-resistant DU145 (DU145-DR) than in parental DU145 cells. Claspin knockdown significantly upregulated the sensitivity to DTX in DU145-DR cells. These results suggest that claspin plays an important role in PCa tumor progression and DTX resistance.

Establishment of oxaliplatin-resistant gastric cancer organoids: importance of myoferlin in the acquisition of oxaliplatin resistance.

BACKGROUND: The attainment of drug resistance in gastric cancer (GC) is a problematic issue. Although many studies have shown that cancer stem cells (CSCs) play an important role in the acquisition of drug resistance, there is no clinically available biomarker for predicting oxaliplatin (L-OHP) resistance in relation to CSCs. Organoid technology, a novel 3D cell culture system, allows harboring of patient-derived cancer cells containing abundant CSCs using niche factors in a dish. METHODS: In this study, we established L-OHP-resistant gastric cancer organoids (GCOs) and evaluated their gene expression profile using microarray analysis. We validated the upregulated genes in the L-OHP-resistant GCOs compared to their parental GCOs to find a gene responsible for L-OHP resistance by qRT-PCR, immunohistochemistry, in vitro, and in vivo experiments. RESULTS: We found myoferlin (MYOF) to be a candidate gene through microarray analysis. The results from cell viability assays and qRT-PCR showed that high expression of MYOF correlated significantly with the IC50 of L-OHP in GCOs. Immunohistochemistry of MYOF in GC tissue samples revealed that high expression of MYOF was significantly associated with poor prognosis, T grade, N grade, and lymphatic invasion, and showed MYOF to be an independent prognostic indicator, especially in the GC patients treated with platinum-based chemotherapy. The knockdown of MYOF repressed L-OHP resistance, cell growth, stem cell features, migration, invasion, and in vivo tumor growth. CONCLUSIONS: Our results suggest that MYOF is highly involved in L-OHP resistance and tumor progression in GC. MYOF could be a promising biomarker and therapeutic target for L-OHP-resistant GC cases.

Clinicopathologic features of TDO2 overexpression in renal cell carcinoma.

BACKGROUND: Tryptophan 2,3-dioxygenase (TDO2) is the primary enzyme catabolizing tryptophan. Several lines of evidence revealed that overexpression of TDO2 is involved in anoikis resistance, spheroid formation, proliferation, and invasion and correlates with poor prognosis in some cancers. The aim of this research was to uncover the expression and biofunction of TDO2 in renal cell carcinoma (RCC). METHODS: To show the expression of TDO2 in RCC, we performed qRT-PCR and immunohistochemistry in integration with TCGA data analysis. The interaction of TDO2 with PD-L1, CD44, PTEN, and TDO2 expression was evaluated. We explored proliferation, colony formation, and invasion in RCC cells line affected by knockdown of TDO2. RESULTS: RNA-Seq and immunohistochemical analysis showed that TDO2 expression was upregulated in RCC tissues and was associated with advanced disease and poor survival of RCC patients. Furthermore, TDO2 was co-expressed with PD-L1 and CD44. In silico analysis and in vitro knockout of PTEN in RCC cell lines revealed the ability of PTEN to regulate the expression of TDO2. Knockdown of TDO2 suppressed the proliferation and invasion of RCC cells. CONCLUSION: Our results suggest that TDO2 might have an important role in disease progression and could be a promising marker for targeted therapy in RCC. (199 words).