Crosstalk between bone metastatic cancer cells and sensory nerves in bone metastatic progression.

Although the role of peripheral nerves in cancer progression has been appreciated, little is known regarding cancer/sensory nerve crosstalk and its contribution to bone metastasis and associated pain. In this study, we revealed that the cancer/sensory nerve crosstalk plays a crucial role in bone metastatic progression. We found that (i) periosteal sensory nerves expressing calcitonin gene-related peptide (CGRP) are enriched in mice with bone metastasis; (ii) cancer patients with bone metastasis have elevated CGRP serum levels; (iii) bone metastatic patient tumor samples express elevated calcitonin receptor-like receptor (CRLR, a CGRP receptor component); (iv) higher CRLR levels in cancer patients are negatively correlated with recurrence-free survival; (v) CGRP induces cancer cell proliferation through the CRLR/p38/HSP27 pathway; and (vi) blocking sensory neuron-derived CGRP reduces cancer cell proliferation in vitro and bone metastatic progression in vivo. This suggests that CGRP-expressing sensory nerves are involved in bone metastatic progression and that the CGRP/CRLR axis may serve as a potential therapeutic target for bone metastasis.

A pediatric case of Burkitt's lymphoma with bile duct obstruction requiring surgical biliary reconstruction.

BACKGROUND: Biliary obstruction due to compression by a B-cell solid tumor occurs rarely. A few reports have described biliary reconstruction surgery for obstructive jaundice caused by Burkitt's lymphoma. However, there are no detailed reports on pediatric cases. We report a pediatric case of obstructive jaundice due to malignant lymphoma treated with biliary reconstruction surgery. CASE PRESENTATION: A 5-year-old girl presented to our hospital with a massive abdominal tumor that caused biliary stricture. Chemotherapy was initiated after an open tumor biopsy. However, endoscopic biliary stent placement was performed owing to elevated bilirubin levels. We treated the patient with chemotherapy for 9 months while endoscopically replacing the biliary stent every few months. She achieved complete tumor remission. However, sclerotic lymph nodes were persistent on the dorsal side of the cholecystic duct junction, and biliary stricture at the same site had changed to stent-dependent biliary obstruction. Therefore, we performed choledochojejunostomy and retrocolic Roux-en-Y reconstruction 15 months after initial admission. There were no postoperative complications or tumor recurrences, and the bilirubin level remained low. Histopathologically, the resected bile duct wall was fibrotic and thick, and the bile duct lumen narrowed. CONCLUSIONS: Biliary reconstruction is effective to achieve long-term biliary patency in pediatric patients with stent-dependent biliary obstruction due to malignant lymphoma. However, the decision on when to stop biliary stent replacement and proceed to biliary reconstruction surgery is a matter of debate. Further case studies are required to address this issue.

Peripherally inserted central catheters can be an alternative to tunneled central venous catheters in chemotherapy for hematological and oncological pediatric patients.

PURPOSE: Tunneled central venous catheters (TCVs) are commonly used for pediatric chemotherapy. Recently, peripherally inserted central catheters (PICCs) have been used instead. Although PICC has the advantages of simpler insertion and fewer severe complications, there is little information on the efficacy of PICC compared to TCV in pediatric chemotherapy. METHODS: Patients, aged younger than 18 years, with primary malignancy who received chemotherapy with PICC or TCV at our institution from December 2007 to August 2022 were included in the study. We retrospectively compared PICC and TCV using medical records. RESULTS: Within the observation period, 133 catheters (73 PICCs and 60 TCVs) were inserted. The median indwelling time was 99 days for PICCs and 182 days for TCVs, with TCVs being significantly longer (p < 0.001). There were no significant differences in the incidence of complications, such as infections, thrombosis, obstruction, or mechanical accidents. Comparing patients treated with PICC (PICC group) versus those with TCV (TCV group), the time from diagnosis to insertion was significantly shorter in the PICC group (p < 0.001). In the PICC group, none of the patients required general anesthesia, and chemotherapy was completed with PICC only. CONCLUSION: PICC can be an alternative to TCV in pediatric chemotherapy.

Prognostic survival biomarkers of tumor-fused dendritic cell vaccine therapy in patients with newly diagnosed glioblastoma.

Dendritic cell (DC)-based immunotherapy has been applied to glioblastoma (GBM); however, biomarkers informing response remain poorly understood. We conducted a phase I/IIa clinical trial investigating tumor-fused DC (TFDC) immunotherapy following temozolomide-based chemoradiotherapy in patients with newly diagnosed GBM and determined prognostic factors in patients receiving TFDC immunotherapy. Twenty-eight adult patients with GBM isocitrate dehydrogenase (IDH) wild-type (IDH-WT) were enrolled; 127 TFDC vaccine injections (4.5 ± 2.6 times/patient) were administered. Patients with GBM IDH-WT had a respectable 5-year survival rate (24%), verifying the clinical activity of TFDC immunotherapy, particularly against O6-methylguanine-DNA methyltransferase (MGMT) unmethylated GBM (5-year survival rate: 33%). To identify novel factors influencing overall survival (OS) in GBM IDH-WT treated with TFDC immunotherapy, clinical parameters were assessed and comprehensive molecular profiling involving transcriptome and exome analyses was performed. MGMT promoter methylation status, extent of tumor resection, and vaccine parameters (administration frequency, DC and tumor cell numbers, and fusion ratio) were not associated with survival following TFDC immunotherapy. Old age and pre- and post-operative Karnofsky performance status were significantly correlated with OS. Low HLA-A expression and lack of CCDC88A, KRT4, TACC2, and TONSL mutations in tumor cells were correlated with better prognosis. We validated the activity of TFDC immunotherapy against GBM IDH-WT, including chemoresistant, MGMT promoter unmethylated cases. The identification of molecular biomarkers predictive of TFDC immunotherapy efficacy in GBM IDH-WT will facilitate the design of and patient stratification in a phase-3 trial to maximize treatment benefits.

Impact of Neoadjuvant Bevacizumab on Neuroradiographic Response and Histological Findings Related to Tumor Stemness and the Hypoxic Tumor Microenvironment in Glioblastoma: Paired Comparison Between Newly Diagnosed and Recurrent Glioblastomas.

Background: Previously, we reported that bevacizumab (Bev) produces histological and neuroradiographic alterations including changes in tumor oxygenation, induction of an immunosupportive tumor microenvironment, and inhibition of stemness. To confirm how those effects vary during Bev therapy, paired samples from the same patients with newly diagnosed glioblastoma (GBM) who received preoperative neoadjuvant Bev (neoBev) were investigated with immunohistochemistry before and after recurrence. Methods: Eighteen samples from nine patients with newly diagnosed GBM who received preoperative neoBev followed by surgery and chemoradiotherapy and then autopsy or salvage surgery after recurrence were investigated. The expression of carbonic anhydrase 9 (CA9), hypoxia-inducible factor-1 alpha (HIF-1α), nestin, and Forkhead box M1 (FOXM1) was evaluated with immunohistochemistry.For comparison between neoBev and recurrent tumors, we divided the present cohort into two groups based on neuroradiographic response: good and poor responders (GR and PR, respectively) to Bev were defined by the tumor regression rate on T1-weighted images with gadolinium enhancement (T1Gd) and fluid-attenuated inversion recovery images. Patterns of recurrence after Bev therapy were classified as cT1 flare-up and T2-diffuse/T2-circumscribed. Furthermore, we explored the possibility of utilizing FOXM1 as a biomarker of survival in this cohort. Results: A characteristic "pseudo-papillary"-like structure containing round-shaped tumor cells clustered adjacent to blood vessels surrounded by spindle-shaped tumor cells was seen only in recurrent tumors. Tumor cells at the outer part of the "pseudo-papillary" structure were CA9-positive (CA9+)/HIF-1α+, whereas cells at the inner part of this structure were CA9-/HIF-1α+ and nestin+/FOXM1+. CA9 and HIF-1α expression was lower in T1Gd-GR and decreased in the "T2-circumscribed/T2-diffuse" pattern compared with the "T1 flare-up" pattern, suggesting that tumor oxygenation was frequently observed in T1Gd-GR in initial tumors and in the "T2-circumscribed/T2-diffuse" pattern in recurrent tumors. FOXM1 low-expression tumors tended to have a better prognosis than that of FOXM1 high-expression tumors. Conclusion: A "pseudo-papillary" structure was seen in recurrent GBM after anti-vascular endothelial growth factor therapy. Bev may contribute to tumor oxygenation, leading to inhibition of stemness and correlation with a neuroimaging response during Bev therapy. FOXM1 may play a role as a biomarker of survival during Bev therapy.

Thoracic esophageal injury due to a neck stab wound: a case report.

BACKGROUND: Traumatic esophageal injury leads to severe complications such as mediastinitis, pyothorax, and tracheoesophageal fistula. Although prompt diagnosis and treatment are required, there are no established protocols to guide diagnosis or treatment. In particular, thoracic esophageal injury tends to be diagnosed later than cervical esophageal injury because it has few specific symptoms. We report a case of thoracic esophageal injury caused by a cervical stab wound; the patient was stabbed with a sharp blade. CASE PRESENTATION: A 74-year-old woman was attacked with a knife while sleeping at home. The patient was taken to the emergency room with an injury localized to the left section of her neck. She was suspected of a left jugular vein and recurrent laryngeal nerve injury from cervical hematoma and hoarseness. On the day following the injury, computed tomography revealed a thoracic esophageal injury. Emergency surgery was performed for an esophageal perforation and mediastinal abscesses. Although delayed diagnosis resulted in suture failure, the patient was able to resume oral intake of food a month later following enteral feeding with a gastrostomy. Esophageal injuries due to sharp trauma are rare, and most are cervical esophageal injuries. There are very few reports on thoracic esophageal injuries. CONCLUSIONS: The possibility of thoracic esophageal injury should always be considered when dealing with neck stab wounds, particularly those caused by an attack.

Laparoscopic appendectomy during the second trimester of a twin pregnancy.

Acute appendicitis during pregnancy may lead to increased maternal and fetal risks. Laparoscopic appendectomy is commonly performed during pregnancy. Compared with open appendectomy in pregnant women, laparoscopic appendectomy has shown non-inferior safety for pregnancy outcomes and superior safety for surgical outcomes. Over the last few decades, the occurrence of twin pregnancy has been increasing. Performing an operation on a patient with a twin pregnancy is more difficult than with a singleton pregnancy. Only a few operations of this kind have been reported. Here, we present a case of a 20-week twin pregnant woman who presented with acute appendicitis. Laparoscopic appendectomy was performed, and no maternal complications occurred. This report contributes to discussions on the safety of the laparoscopic approach for appendicitis during twin pregnancies.

Differential expression of androgen receptor variants in hormone-sensitive prostate cancer xenografts, castration-resistant sublines, and patient specimens according to the treatment sequence.

BACKGROUND: Androgen receptor variants (AR-vs), especially AR-v7 and AR-v 5, 6, and 7 exon-skipped (AR-v567es), are reportedly key players in the development of castration-resistant prostate cancer (CRPC). We previously established a mouse xenograft model (JDCaP) from a metastatic skin lesion from a Japanese patient with CRPC and that was revealed to exhibit androgen sensitivity. In the present study, we established multiple castration-resistant xenograft models from JDCaP mice to investigate the biological features of CRPC. METHODS: Tissue from JDCaP mice was transplanted into male and female nude mice, and after serial passaging, castration-resistant sublines (JDCaP-CR2M and JDCaP-CR4M in male mice, JDCaP-CR2F and JDCaP-CR4F in female mice) were established. We investigated anti-androgen and testosterone sensitivity and the messenger RNA expression pattern of full-length AR and AR-vs. In addition, we compared AR protein levels of patient specimens among primary, local-recurrent, and two skin-metastatic tumors. RESULTS: All JDCaP-CR sublines showed continuous growth following the administration of bicalutamide, although the effects of testosterone varied among sublines. Parental JDCaP and JDCaP-CR2M, JDCaP-CR4M, and JDCaP-CR4F sublines expressed AR-v7, whereas JDCaP-CR2F exhibited elevated AR-v567es expression resulting from genomic deletion, which was confirmed by DNA sequencing. Moreover, we confirmed AR-v7 expression in the tumor of the original patient after androgen-deprivation therapy. CONCLUSIONS: Each JDCaP-CR subline showed different AR-v-expression patterns, with JDCaP-CR2F expressing AR-v567es due to genomic deletion. Our results indicated that AR-vs emerged after androgen-deprivation therapy and appeared essential for acquisition of castration resistance.

Comparison of ERG and SPINK1 expression among incidental and metastatic prostate cancer in Japanese men.

BACKGROUND: TMPRSS2:ERG fusion is the most common genetic event in prostate cancer (PCa). However, its association with prognosis is controversial. Overexpression of serine protease inhibitor Kazal-type 1 (SPINK1) was almost exclusively defined in ERG-negative PCa in most studies. This study aimed to determine the association between ERG and SPINK1 expression and the biological aggressiveness of PCa by analyzing their expression in incidental and metastatic cohorts. METHODS: A total of 143 cystoprostatectomy specimens of invasive bladder cancer and 98 biopsy specimens from de novo metastatic PCa were analyzed. The prostate gland of cystoprostatectomy specimens was fixed and sliced in step sections. Immunohistochemistry of ERG and SPINK1 was conducted, and the results were correlated with the clinicopathological characteristics of the patients. RESULTS: The overall prevalence of incidental cancer was 32.2% (46/143). The frequencies of both ERG and SPINK1 expression were not significantly different between incidental and metastatic cohorts (15.2% and 14.3%; P = 1.00, and 6.5% and 12.2%; P = 0.38, respectively). In the metastatic cohort, any pre-treatment factors were not significantly associated with the frequencies of ERG and SPINK1 expression. However, SPINK1 expression was significantly associated with a shorter time to castration-resistant PCa (CRPC) (P = 0.048). Meanwhile, overall survival was not significantly associated with the expression status of ERG and SPINK1 (P = 0.71). CONCLUSIONS: ERG and SPINK1 expression may not have significant influence on the metastatic behavior of PCa. SPINK1 expression was significantly associated with a shorter time to CRPC in metastatic PCa. The expression profile of ERG and SPINK1 may be a useful predictor for effect of androgen deprivation therapy in patients with metastatic castration-sensitive PCa.

Claudin 7 as a possible novel molecular target for the treatment of pancreatic cancer.

BACKGROUND/OBJECTIVES: Pancreatic cancer consists of various subpopulations of cells, some of which have aggressive proliferative properties. The molecules responsible for the aggressive proliferation of pancreatic cancer may become molecular targets for the therapies against pancreatic cancer. METHODS: From a human pancreatic cancer cell line, MIA PaCa-2, MIA PaCa-2-A cells with an epithelial morphology and MIA PaCa-2-R cells with a non-epithelial morphology were clonogenically isolated by the limiting dilution method. Gene expression of these subpopulations was analyzed by DNA microarray. Gene knockdown was performed using siRNA. RESULTS: Although the MIA PaCa-2-A and MIA PaCa-2-R cells displayed the same DNA short tandem repeat (STR) pattern identical to that of the parental MIA PaCa-2 cells, the MIA PaCa-2-A cells were more proliferative than the MIA PaCa-2-R cells both in culture and in tumor xenografts generated in immunodeficient mice. Furthermore, the MIA PaCa-2-A cells were more resistant to gemcitabine than the MIA PaCa-2-R cells. DNA microarray analysis revealed a high expression of claudin (CLDN) 7 in the MIA PaCa-2-A cells, as opposed to a low expression in the MIA PaCa-2-R cells. The knockdown of CLDN7 in the MIA PaCa-2-A cells induced a marked inhibition of proliferation. The MIA PaCa-2-A cells in which CLDN7 was knocked down exhibited a decreased expression of phosphorylated extracellular signal-regulated kinase (p-Erk)1/2 and G1 cell cycle arrest. CONCLUSIONS: CLDN7 may be expressed in the rapidly proliferating and dominant cell population in human pancreatic cancer tissues and may be a novel molecular target for the treatment of pancreatic cancer.

7-Ketocholesterol enhances leukocyte adhesion to endothelial cells via p38MAPK pathway.

7-Ketocholesterol is a major dietary cholesterol oxidation product found in high concentrations in atherosclerotic plaques, which contribute to the development of atherosclerosis. This study aimed to investigate the effects of 7-ketocholesterol on endothelial inflammation, as well as the underlying mechanisms. Pretreatment of human umbilical vein endothelial cells (HUVEC) with 7-ketocholesterol significantly enhanced the total interactions between human monocytic cells (THP-1 cell line) and TNFα-activated HUVECs under physiological flow conditions, compared to pretreatment with cholesterol (TNFα+50 µM cholesterol: 13.1 ± 0.54 cells/CPF, TNFα+50 µM 7-ketocholesterol: 18.9 ± 0.35 cells/CPF, p < 0.01). 7-Ketocholesterol enhanced the expression of E-selectin, ICAM-1, and VCAM-1 proteins. It also activated p38 mitogen-activated protein kinase (MAPK), and treatment with a p38 MAPK inhibitor inhibited both E-selectin expression via ATF-2 activation and 7-ketocholesterol-induced THP-1 adhesion to HUVECs. These findings suggest that 7-ketocholesterol enhances leukocyte-endothelial interactions by upregulating the expression of adhesion molecules, presumably via the p38 MAPK-dependent pathway.

Nafamostat mesilate, a serine protease inhibitor, suppresses interferon-gamma-induced up-regulation of programmed cell death ligand 1 in human cancer cells.

Programmed cell death ligand-1 (PD-L1) plays a pivotal role in the suppression of antitumour immunity by binding to programmed cell death-1 (PD-1) on tumouricidal cytotoxic T lymphocytes (CTLs), rendering them inactive. As blockade of PD-1/PD-L1 interaction by the monoclonal antibodies induced effective T cell-mediated antitumour response, suppression of PD-L1 expression in tumour cells by the chemical agent might contribute to treatment against malignant tumours. Nafamostat mesilate (NM), a serine protease inhibitor that is frequently used in the clinic, potently suppressed interferon-gamma (IFN-gamma)-induced up-regulation of PD-L1 in cultured human lung cancer cells (HLC-1) at both the messenger RNA (mRNA) and protein levels. Interestingly, suppression of IFN-gamma-induced up-regulation of human leukocyte antigen (HLA)-ABC by NM was limited, suggesting that NM did not block CTL responses to tumour cells. NM treatment did not affect the activation status of signal transducer and activator of transcription (STAT) 1 or the induction of interferon regulatory factor (IRF)-1 expression in IFN-gamma-treated HLC-1 cells. Although NM treatment promoted the phosphorylation of extracellular signal-regulated kinases (Erk) 1/2, an Erk inhibitor, U0126, could not reverse the suppression of PD-L1 up-regulation by IFN-gamma. Suppression of IFN-gamma-induced up-regulation of PD-L1 by NM was not associated with the inhibition of nuclear factor kappa B (NF-kB) or protease-activated receptor (PAR)-1 pathway. Besides HLC-1 cells, NM suppressed IFN-gamma-induced PD-L1 up-regulation in three human pancreatic cancer cell lines. NM could potentiate the antitumour effect of cancer vaccines or immune checkpoint inhibitors by preventing IFN-gamma-induced PD-L1 up-regulation and blocking immune checkpoint suppression.

A straightforward assay for measuring glycogen levels and RpoS.

Cellular glycogen levels reflect the activity of RpoS, an important stress-inducible bacterial sigma factor known to regulate several stress-resistance related genes, such as katE, encoding hydroperoxidase II (HPII), and the glg genes, encoding glycogen synthesis enzymes, in Escherichia coli. In this study, a straightforward assay for measuring glycogen levels and RpoS activity was developed combining the ease and simplicity of qualitative approaches. The assay reagent was a 2% iodine solution (2% iodine/1M NaOH), and the basic principle of this assay is the iodine-glycogen reaction, which produces a reddish brown color that can be measured using a spectrophotometer. A calibration plot using a known amount of glycogen yielded the best linear fit over a range of 10-300µg/assay (R2=0.994). The applicability of the assay for measuring the glycogen level of various samples was assessed using a wild type (WT) E. coli K-12 strain, glycogen- and RpoS-deficient isogenic mutants, and clinical bacterial isolates with or without RpoS activity; the assay generated reproducible results. Additionally, the assay was successfully applied for measuring glycogen levels in human cells. In conclusion, we developed a straightforward and cost-effective assay for measuring glycogen levels, which can be applied for measuring RpoS activity.

A Novel Near-infrared Fluorescent Protein, iRFP720, Facilitates Transcriptional Profiling of Prostate Cancer Bone Metastasis in Mice.

BACKGROUND: Bone represents a frequent site of prostate cancer metastasis. As the molecular mechanism remains unclear, an accessible animal model is required. MATERIALS AND METHODS: We established a novel murine metastasis model using near-infrared fluorescent protein iRFP720-labelled prostate cancer (PC3) cells. To clarify transcriptional alterations during metastasis, iRFP720-PC3 cells were intracardially injected into male mice. mRNA expression profiles of metastasis in bone using marrow cancer cells extracted by centrifugal separation and cell sorting were compared with those of parental cells by microarray. Differentially expressed genes were analyzed by pathway analysis. RESULTS: We identified 327 and 197 genes being up- and down-regulated, respectively. Pathway analysis revealed that the p53 signaling pathway, extracellular matrix receptor interaction, Mammalian target of rapamycin signaling pathway, cancer-related pathways, small cell lung cancer, and Escherichia coli infection response were altered. CONCLUSION: iRFP720 is useful for in vivo cell detection/isolation. The results of expression analysis may improve prostate cancer treatment strategies.

[EXPRESSION OF PLAKIN FAMILY IN UROTHELIAL CARCINOMA OF THE UPPER URINARY TRACT].

(Objective) To determine whether the plakin family proteins periplakin, desmoplakin, plectin, and envoplakin could be markers of urothelial carcinoma of the upper urinary tract. (Materials and methods) Fifty-seven surgical specimens were obtained from patients with urothelial carcinoma of the upper urinary tract, who were admitted to the Jikei University Hospital between April 2000 and December 2005. The expression of plakin family proteins in cancerous and normal tissues was investigated using immunohistochemistry, and its association with clinicopathological parameters was analyzed. (Results) The expression of periplakin, envoplakin, and desmoplakin was significantly lower in cancerous tissue than in normal urothelium (P < 0.0001, P < 0.0001, and P < 0.0001, respectively). Strong desmoplakin expression in cancerous tissue was significantly associated with poor cancer-specific survival and overall survival (P = 0.023 and P = 0.034, respectively, compared with cancerous tissue with slight or less desmoplakin expression). Furthermore, strong plectin expression was significantly associated with poor metastasis-free survival (P = 0.034, compared with cancerous tissue with slight or less plectin expression). (Conclusion) Plakin family, particularly desmoplakin was suggested to be a prognostic marker of urothelial carcinoma of the upper urinary tract.

Gemcitabine enhances rituximab-mediated complement-dependent cytotoxicity to B cell lymphoma by CD20 upregulation.

Although rituximab, a chimeric monoclonal antibody that specifically binds to CD20, has significantly improved the prognosis for diffuse large B cell lymphoma (DLBCL), one-third of DLBCL patients demonstrate resistance to rituximab or relapse after rituximab treatment. Thus, a novel approach to rituximab-based treatment is likely to be required to improve the efficacy of DLBCL treatment. As complement dependent cytotoxicity (CDC) is a key mechanism mediating rituximab's tumoricidal activity, rituximab binding to CD20 on tumor cells is a critical factor for effective rituximab-based treatments against DLBCL. We found that gemcitabine (GEM), but not lenalidomide (LEN) or azacitidine (AZA), can upregulate CD20 expression in TK and KML-1 cells, two human DLBCL cell lines. Treatment of TK and KML-1 cells with GEM enhanced CD20 expression at both the mRNA and protein levels. CD20 upregulation by GEM treatment was accompanied by increased rituximab binding to CD20. In TK cells, GEM treatment synergistically increased rituximab-mediated CDC activity in a dose-dependent manner. In KML cells, GEM treatment also induced upregulation of complement regulatory proteins, possibly leading to resistance to CDC. Treatment with LEN, a drug that did not upregulate CD20, did not enhance rituximab-mediated CDC activity. GEM treatment activated nuclear factor-kappa B (NF-kB) signaling in these cells. Furthermore, a specific inhibitor to NF-kB suppressed GEM-induced CD20 upregulation, indicating that GEM-induced NF-kB activation is closely associated with CD20 upregulation. These results suggest that when used in combination, GEM might enhance the antitumor efficacy of rituximab against DLBCL due to its unique ability to upregulate CD20.

Up-regulation of HER2 by gemcitabine enhances the antitumor effect of combined gemcitabine and trastuzumab emtansine treatment on pancreatic ductal adenocarcinoma cells.

BACKGROUND: Although pancreatic ductal adenocarcinomas (PDAs) widely express HER2, the expression level is generally low. If HER2 expression in PDA cells could be enhanced by treatment with a given agent, then combination therapy with that agent and trastuzumab emtansine (T-DM1), a chemotherapeutic agent that is a conjugate of trastuzumab, might lead to significant antitumor effects against PDA. METHODS: Cell proliferation was examined by spectrophotometry. HER2 expression was examined by flow cytometry, immunoblot and quantitative reverse transcription polymerase chain reaction. T-DM1 binding to cells was examined by flow cytometry and enzyme-linked immunosorbent assay. RESULTS: Out of 5 tested human PDA cell lines, including MIA PaCa-2, three showed increases in HER2 expression after gemcitabine (GEM) treatment. The binding of T-DM1 to GEM-treated MIA PaCa-2 cells was higher than to untreated MIA PaCa-2 cells. Treatment with GEM and T-DM1 showed synergic cytotoxic effects on MIA PaCa-2 cells in vitro. Cells in the G2M phase of the cell cycle were retained after GEM treatment and showed higher levels of HER2 expression, possibly contributing to the synergic effect of GEM and T-DM1. CONCLUSIONS: Combined treatment with GEM and T-DM1 might confer a potent therapeutic modality against PDA as a result of GEM-mediated HER2 up-regulation.

Expression of immune checkpoint molecules of T cell immunoglobulin and mucin protein 3/galectin-9 for NK cell suppression in human gastrointestinal stromal tumors.

Monoclonal antibody therapy for immune checkpoint blockade has achieved promising results for several types of malignant tumors. For the future treatment of gastrointestinal stromal tumors (GISTs) by immune checkpoint blockade, expression of immune checkpoint-related molecules that suppress antitumor immunity in GISTs was examined. Infiltration of immune cell types into 19 GIST tissues was analyzed by immunohistochemistry, and expression of T cell immunoglobulin and mucin protein 3 (Tim-3) and programmed cell death-1 (PD-1) in the infiltrated immune cells was examined by immunofluorescence microscopy. The expression status of galectin-9 in the GIST tumor cells was also determined by immunohistochemistry. All the GIST tissues showed CD8+ T cell infiltration and 8 showed CD56+ natural killer (NK) cell infiltration, and the numbers of infiltrated CD8+ T and NK cells were strongly correlated. However, these CD8+ T and NK cells were CD69-negative inactivated cells. Tim-3 was expressed in the infiltrated NK cells in 6/8 (75%) of the GIST tissues. Expression of galectin-9, a ligand of Tim-3, was observed in 13/19 (68.4%) GIST tissues and all of the GIST tissues with Tim-3+ NK cell infiltration showed positive galectin-9 expression. No PD-1 expression in the infiltrated NK cells and neither Tim-3 nor PD-1 expression was observed in the infiltrated CD8+ T cells. Interaction between Tim-3 in infiltrated NK cells and galectin-9 in tumor cells may be involved in an immune checkpoint mechanism for suppression of antitumor immunity in GISTs. Blockade of the Tim-3/galectin-9 pathway may become a new strategy for GIST treatment.

Gemcitabine treatment enhances HER2 expression in low HER2-expressing breast cancer cells and enhances the antitumor effects of trastuzumab emtansine.

Trastuzumab emtansine (T-DM1), trastuzumab-conjugated with a cytotoxic agent, has shown promising antitumor effects in breast cancer. Since a good therapeutic response using T-DM1 treatment requires high human epidermal growth factor receptor 2 (HER2) expression, breast cancers with low or no HER2 expression have not been used for T-DM1 treatment. The aim of the present study was to show that treatment of low HER2-expressing breast cancer cells with gemcitabine (GEM) enhanced HER2 expression using RT-qPCR, immunoblot and flow cytometric analysis. The results showed that GEM treatment significantly enhanced HER2 expression in MDA-MB-231, MCF7 and BT-20 breast cancer cells, while paclitaxel (PTX) treatment induced lower or no enhancement in HER2 expression. The expression of HER2 mRNA was also enhanced in GEM-treated MCF7 cells. Treatment with an inhibitor for nuclear factor-(NF)-κB suppressed GEM-induced HER2 upregulation, indicating that NF-κB activation by GEM may be associated with HER2 upregulation. T-DM1 binding to HER2 on MCF-7 cells was enhanced by GEM pretreatment and the combined treatment of GEM and T-DM1 synergistically inhibited the proliferation of MCF7 cells. Thus, the combined treatment with GEM and T-DM1 may be a promising therapeutic modality for low HER2-expressing breast cancers, which was facilitated by the unique HER2-upregulating effect of GEM.

Treatment with chemotherapy and dendritic cells pulsed with multiple Wilms' tumor 1 (WT1)-specific MHC class I/II-restricted epitopes for pancreatic cancer.

PURPOSE: We performed a phase I trial to investigate the safety, clinical responses, and Wilms' tumor 1 (WT1)-specific immune responses following treatment with dendritic cells (DC) pulsed with a mixture of three types of WT1 peptides, including both MHC class I and II-restricted epitopes, in combination with chemotherapy. EXPERIMENTAL DESIGN: Ten stage IV patients with pancreatic ductal adenocarcinoma (PDA) and 1 patient with intrahepatic cholangiocarcinoma (ICC) who were HLA-positive for A*02:01, A*02:06, A*24:02, DRB1*04:05, DRB1*08:03, DRB1*15:01, DRB1*15:02, DPB1*05:01, or DPB1*09:01 were enrolled. The patients received one course of gemcitabine followed by biweekly intradermal vaccinations with mature DCs pulsed with MHC class I (DC/WT1-I; 2 PDA and 1 ICC), II (DC/WT1-II; 1 PDA), or I/II-restricted WT1 peptides (DC/WT1-I/II; 7 PDA), and gemcitabine. RESULTS: The combination therapy was well tolerated. WT1-specific IFNγ-producing CD4(+) T cells were significantly increased following treatment with DC/WT1-I/II. WT1 peptide-specific delayed-type hypersensitivity (DTH) was detected in 4 of the 7 patients with PDA vaccinated with DC/WT1-I/II and in 0 of the 3 patients with PDA vaccinated with DC/WT1-I or DC/WT1-II. The WT1-specific DTH-positive patients showed significantly improved overall survival (OS) and progression-free survival (PFS) compared with the negative control patients. In particular, all 3 patients with PDA with strong DTH reactions had a median OS of 717 days. CONCLUSIONS: The activation of WT1-specific immune responses by DC/WT1-I/II combined with chemotherapy may be associated with disease stability in advanced pancreatic cancer.