Balamuthia mandrillaris amoebic encephalitis mimicking tuberculous meningitis.

A 76-year-old female with no apparent immunosuppressive conditions and no history of exposure to freshwater and international travel presented with headache and nausea 3 weeks before the presentation. On admission, her consciousness was E4V4V6. Cerebrospinal fluid analysis showed pleocytosis with mononuclear cell predominance, elevated protein, and decreased glucose. Despite antibiotic and antiviral therapy, her consciousness and neck stiffness gradually worsened, right eye-movement restriction appeared, and the right direct light reflex became absent. Brain magnetic resonance imaging revealed hydrocephalus in the inferior horn of the left lateral ventricle and meningeal enhancement around the brainstem and cerebellum. Tuberculous meningitis was suspected, and pyrazinamide, ethambutol, rifampicin, isoniazid, and dexamethasone were started. In addition, endoscopic biopsy was performed from the white matter around the inferior horn of the left lateral ventricle to exclude brain tumor. A brain biopsy specimen revealed eosinophilic round cytoplasm with vacuoles around blood vessels, and we diagnosed with amoebic encephalitis. We started azithromycin, flucytosine, rifampicin, and fluconazole, but her symptoms did not improve. She died 42 days after admission. In autopsy, the brain had not retained its structure due to autolysis. Hematoxylin and eosin staining of her brain biopsy specimen showed numerous amoebic cysts in the perivascular brain tissue. Analysis of the 16S ribosomal RNA region of amoebas from brain biopsy and autopsy specimens revealed a sequence consistent with Balamuthia mandrillaris. Amoebic meningoencephalitis can present with features characteristic of tuberculous meningitis, such as cranial nerve palsies, hydrocephalus, and basal meningeal enhancement. Difficulties in diagnosing amoebic meningoencephalitis are attributed to the following factors: (1) excluding tuberculous meningitis by microbial testing is difficult, (2) amoebic meningoencephalitis has low incidence and can occur without obvious exposure history, (3) invasive brain biopsy is essential in diagnosing amoebic meningoencephalitis. We should recognize the possibility of amoebic meningoencephalitis when evidence of tuberculosis meningitis cannot be demonstrated.

Gastric carcinosarcoma with FGFR2 amplification under long-term control with pazopanib: a case report and literature review.

BACKGROUND: Gastric carcinosarcoma is most frequently diagnosed at an advanced stage when the tumor is generally large with invasion into other organs, lymph node metastasis, and distant metastasis. Standard chemotherapy has not been established, and surgery is the only curative treatment. Here, we present a case of postoperative recurrence of gastric carcinosarcoma under long-term tumor control with pazopanib. CASE PRESENTATION: A 77-year-old man was referred to our hospital because of nausea and vomiting. Computed tomography and upper gastrointestinal endoscopy revealed a type 1 tumor arising from the gastric antrum and extending into the duodenal bulb. He underwent distal gastrectomy (D2) with Roux-en-Y reconstruction. Histopathologically, the tumor had mixed adenocarcinoma and sarcoma components. According to the tumor-node-metastasis classification, the diagnosis was primary gastric carcinosarcoma pT1bN1M0 stage IB. Liver metastasis was detected 2 months after surgery; multiple lung metastases were detected 17 month after surgery. A genomic profiling test was performed using liver specimens as the patient became refractory to chemotherapy commonly used for gastric cancer, and the test revealed FGFR2 amplification along with TP53 R209*, AKT3 N127D, NOTCH1 A2036T, and POLD1 M161I. The patient was treated with pazopanib (800 mg/daily), and the tumor growth was controlled for 11 months. CONCLUSIONS: We report a case of postoperative recurrence of gastric carcinosarcoma under long-term tumor control with pazopanib. This case suggested that pazopanib may be effective in treating gastric carcinosarcoma.

Diagnosis and treatment of primary central nervous system lymphoma with the primary lesion in the hypothalamus: a case report.

BACKGROUND: Primary central nervous system lymphoma is a rare extra-nodal lymphoma of the central nervous system. Primary central nervous system lymphoma lesions usually appear in the vicinity of the ventricle, and there are few reports of primary central nervous system lymphoma with hypothalamic-pituitary lesions. CASE PRESENTATION: We treated a 56-year-old male with primary central nervous system lymphoma with the primary lesion in the hypothalamus, which was found by magnetic resonance imaging after sudden onset of endocrinological abnormalities. Initially, he was hospitalized to our department for hyponatremia. Endocrinological examination in conjunction with head magnetic resonance imaging and endoscopic biopsy revealed hypothalamic hypopituitarism and tertiary hypoadrenocorticism caused by a rapidly growing, diffuse large B-cell lymphoma in the hypothalamus. Remission of the tumor was achieved by high-dose methotrexate with whole brain radiotherapy, and some of the hormone responses were normalized. CONCLUSIONS: While primary central nervous system lymphoma is rare, it is important to note that hypopituitarism can result and that the endocrinological abnormalities can be partially restored by its remission.

Solitary Fibrous Tumor of the Prostate: A Case Report and Literature Review.

Solitary fibrous tumors (SFTs) usually occur in the pleura and account for two-thirds of all cases; however, SFTs occurring in the prostate are extremely rare. Approximately 25 cases have been reported in the literature to date. This study reports the case of a 43-year-old man referred to our hospital with the chief complaint of a pelvic tumor after careful examination. The tumor marker levels were within normal limits. T2-weighted magnetic resonance imaging revealed a tumor, demonstrating primarily low signal intensity. It showed a capsule-like rim at the left lobe of the prostate, suggesting that the tumor was partially invading the rectal wall. Histopathological examination of needle-core biopsies showed spindle cell neoplasm with small and fusiform cells, strongly expressing signal transducer and activator of transcription 6 (STAT6) with a ramifying vascular network. Therefore, the clinical diagnosis of the patient was SFT of the prostate and robot-assisted radical prostatectomy was performed. Histopathological examination revealed that the tumor was composed of spindle cells with patternless and staghorn patterns. Immunohistochemical analysis showed a strong expression of STAT6. Furthermore, the tumor was partially positive for CD34. Therefore, the patient was diagnosed with SFT of the prostate. Two years after the initial diagnosis, the patient was alive with normal erectile function, continence status, and no evidence of the disease.

Endoscopic and Pathological Characteristics of Helicobacter pylori Infection-Negative Early Gastric Cancer.

BACKGROUND: The characteristics of Helicobacter pylori (HP) infection-negative gastric cancer (HPINGC) have not been well documented because of the rareness. The aim of this study was to classify HPINGC endoscopically and clinicopathologically. METHODS: This retrospective study included 1,741 early gastric cancer lesions and evaluated their HP infection status. Expression levels of MUC5AC, MUC6, MUC2, CD10, p53, MIB-1, pepsinogen-I, H+/K+ ATPase, chromogranin A, E-cadherin, and gastrin were evaluated in tumors by immunohistochemistry (IHC). RESULTS: Among the analyzed lesions, 19 (1.1%) were diagnosed as HPINGC and classified into 6 types: undifferentiated (5 lesions), fundic gland (2 lesions), cardiac gland (1 lesion), pyloric gland (3 lesions), foveolar (5 lesions), and mixed (3 lesions) types. Undifferentiated lesions were of pale color, with unclear demarcation and decreased E-cadherin expression. Fundic-type lesions were tan to reddish in color, with submucosal tumor-like protrusions, and positive for pepsinogen-I and H+/K+ ATPase. The cardiac gland type was located in the gastroesophageal junction and was positive for MUC6 and pepsinogen-I. Pyloric gland-type lesions were of the same color as normal mucosa, with mild elevation and unclear demarcation, likely positive for CD10 and chromogranin A. Foveolar epithelial-type lesions were white and elevated, with defined demarcation, and contained MUC5AC-positive cells. Mixed-type lesions, showing various staining patterns in IHC, had both elevated and depressed shape and reddish color. CONCLUSION: Endoscopic observation and IHC were useful for classifying the characteristics of HPINGC, which may preserve the characteristics of its region of origin.

An adiponectin paralog protein, CTRP6 decreased the proliferation and invasion activity of oral squamous cell carcinoma cells: possible interaction with laminin receptor pathway.

C1q/tumor necrosis factor-related protein-6 (CTRP6), also known as CTRP6 is identified adiponectin paralog. Although recent studies have revealed that adiponectin has an inhibitory role in carcinogenesis, the role of CTRP6 in carcinogenesis remains unclear. In this study, we found that eukaryotic recombinant CTRP6 protein bound to the cell surface membrane of cultured oral squamous cell carcinoma cells by immunofluorescence staining. Screening of CTRP6 binding protein in expression library followed by co-immunoprecipitation assay revealed that CTRP6 bound to the precursor of laminin receptor. CTRP6 disturbed the binding of laminin to the laminin receptor. Interestingly, the eukaryotic recombinant CTRP6 protein significantly suppressed the proliferation and Matrigel invasion activity of oral squamous cell carcinoma SAS cells in a dose-dependent manner. Moreover, administration of CTRP6 significantly attenuated the growth of SAS cells in xenoplant mice model. Laminin and laminin receptor are known to be overexpressed and promote the tumor growth in OSCC. Combined together, the present findings suggest that CTRP6 could repress progression of oral squamous cell carcinoma cells, putatively through disrupting the laminin-laminin receptor axis.

TMEM207 hinders the tumour suppressor function of WWOX in oral squamous cell carcinoma.

The WW domain-containing oxidoreductase (WWOX) functions as a tumour suppressor in oral carcinogenesis. As aberrant TMEM207 expression may lead to tumour progression by hampering the tumour suppressor function of WWOX in various cancers, we explored the expression and pathobiological properties of TMEM207, focusing on the WWOX-mediated regulation of the HIF-1α pathway in oral squamous cell carcinoma (OSCC). TMEM207 immunoreactivity was detected in 40 of 90 OSCC samples but not in neighbouring non-tumorous epithelial tissues. Moreover, TMEM207 expression was significantly correlated with lymph node metastasis and poor prognosis. An in situ proximal ligation assay demonstrated the colocalization of TMEM207 and WWOX in invasive OSCC cells, especially glycogen-rich ones. Enforced expression of TMEM207 abrogated the binding of WWOX to HIF-1α, increased HIF-1α and GLUT-1 expression, even under normoxic conditions, and promoted tumour growth in a xenoplant assay using SAS tongue squamous cancer cells. In contrast, TMEM207 knockdown decreased GLUT-1 expression in two OSCC cell lines. As a whole, our findings indicate that the aberrant expression of TMEM207 contributes to tumour progression in OSCC, possibly via promoting aerobic glycolysis.

Novel Transgenic Mouse Model of Polycystic Kidney Disease.

Transmembrane protein 207 (TMEM207) is characterized as an important molecule for invasiveness of gastric signet-ring cell carcinoma cells. To clarify the pathobiological effects of TMEM207, we generated 13 transgenic mouse strains, designated C57BL/6-transgenic (Tg) (ITF-TMEM207), where the mouse Tmem207 is ectopically expressed under the proximal promoter of the murine intestinal trefoil factor gene. A C57BL/6-Tg (ITF-TMEM207) mouse strain unexpectedly exhibited a high incidence of spontaneous kidney cysts with histopathological features resembling human polycystic kidney disease, which were found in approximately all mice within 1 year. TMEM207 immunoreactivity was found in noncystic kidney tubules and in renal cysts of the transgenic mice. The ITF-TMEM207 construct was inserted into Mitf at chromosome 6. Cystic kidney was not observed in other C57BL/6-Tg (ITF-TMEM207) transgenic mouse strains. Although several genetically manipulated animal models exist, this mouse strain harboring a genetic mutation in Mitf and overexpression of Tmem207 protein was not reported as a model of polycystic kidney disease until now. This study demonstrates that the C57BL/6-Tg (ITF-TMEM207) mouse may be a suitable model for understanding human polycystic kidney disease.

The diagnosis of a metastatic breast tumor from ovarian cancer by the succession of a p53 mutation: a case report.

BACKGROUND: Metastatic breast tumors from other organs are very rare. We herein describe the case of a patient with a metastatic breast tumor due to ovarian cancer who was diagnosed by the succession of a p53 mutation. CASE PRESENTATION: The patient was a 59-year-old woman with sigmoid colon stenosis. Diagnostic imaging revealed a pelvic mass, multiple liver tumors, ascites, and multiple swollen para-aortic lymph nodes, suggesting an advanced ovarian tumor. Transverse loop colostomy and partial resection of the greater omentum was performed followed by six cycles of paclitaxel with carboplatin chemotherapy (TC therapy). Her cancer almost disappeared, with the exception of a small tumor in her pelvis. Simple hysterectomy with bilateral salpingo-oophorectomy was performed. Two years and 5 months after the second surgery, a mass was detected in her right breast and simple mastectomy was performed. A histological examination of the tumors from the first surgery revealed infiltrating papillary adenocarcinoma and the solid nest proliferation of atypical cells with comedo necrosis and psammoma bodies. The findings of an immunohistochemical analysis were as follows: cancer antigen 125 (CA125 (+)), cytokeratin 7 (CK7 (+)), cytokeratin 20 (CK20 (-)), p53 (+) and CDX2 (-), estrogen receptor (ER (slightly +)), progesterone receptor (PR (slightly +)), and human epidermal growth factor receptor 2 (HER2 (1+)). The breast tumors presented similar morphological features (ER (-), PR (-), HER2 (-), CA125 (+), CK7 (+), CK20 (-), p53 (+), mammaglobin (-), and GCDFP15 (-)), which were not characteristic of breast cancer. A direct sequencing analysis of p53 revealed a p.V173M mutation in exon 5 in both the breast tumor and the ovarian cancer. It was not detected in normal tissue, suggesting that the breast tumors were metastatic serous adenocarcinomas from ovarian cancer. CONCLUSIONS: A direct sequencing mutation analysis of p53 was useful for distinguishing the primary tumor from the metastatic tumor. We should resect metastatic breast tumors to the extent that is possible because the prognosis of such patients is relatively good.

Adiponectin and Intelectin-1: Important Adipokine Players in Obesity-Related Colorectal Carcinogenesis.

Overweight is believed to be associated with colorectal cancer risk. Adipose tissue is loose connective tissue composed of adipocytes. It is now recognized as a major endocrine organ, secreting humoral factors collectively called adipokines. Aberrant hormonal systems consisting of modulated adipokines and their receptors are thought to play a role in colorectal carcinogenesis and cancer progression in obese conditions. However, it is still unclear whether and how each adipokine relates to colorectal carcinogenesis. Notably, a couple of molecules that were initially proposed to be obesity-related adipokines were disqualified by subsequent studies. The adipokines, adiponectin, and intelectin-1 (also known as omentin-1), whose levels are decreased in obesity, act as tumor suppressor factors in various cancers. Numerous studies have demonstrated a link between the insufficient expression and function of adiponectin and its receptor, T-cadherin, in colorectal carcinogenesis. Moreover, our recent study indicated that loss of TMEM207, which is critical for the proper processing of intelectin-1 in the colon mucosa, leads to insufficient intelectin-1 production, thus participating in colorectal carcinogenesis. Here, we discuss the recent understanding of the role of adipokines in colorectal carcinogenesis and subsequently describe the potent tumor suppressor roles of intelectin-1 and TMEM207 in colorectal cancer.

Complete bone regeneration in hemophilic pseudotumor of the mandible.

Hemophilic pseudotumor (HP) is rare, seen in 1-2% of patients with hemophilia, and is extremely uncommon in the mandible. A 6-year-old boy with moderate hemophilia A presented to our hospital with left mandibular swelling. Based on clinical and radiological findings, a tentative diagnosis of HP was made. After factor VIII administration, the lesion was curetted and HP was confirmed on histopathology. The patient was treated with twice-weekly factor VIII until the lesion had completely resolved and bone had regenerated at 1 year. The best treatment for HP is not established; however, appropriate initial treatment and postoperative prophylaxis are effective.

Case of recurrence of spiradenoma in palpebral conjunctiva.

BACKGROUND: To report a rare case of a recurrence of spiradenoma that developed in the upper eyelid. CASE PRESENTATION: A 49-year-old woman who had a second recurrence of a tumor in the right palpebral conjunctiva underwent local resection of the lesion with adjunctive cryotherapy to the surgical site. The tumor consisted of smooth, round to oval nodular lesions approximately 1-3 mm in size with enlarged blood vessels. Histopathologically, the solid and well-circumscribed nodule was located beneath the conjunctival epithelium. It was composed of cells with slightly basophilic-to-clear cytoplasm and round-to-oval nuclei arranged in a trabecular pattern. Periodic acid-Schiff stain was positive in the cytoplasm, and the staining disappeared after digesting by diastase. Many cells in mitosis were observed throughout the tumor but no necrotic cells. Immunohistochemistry showed that the Ki-67 labeling index was 12%. From these findings, we diagnosed this tumor as a recurrence of the spiradenoma. There has been no recurrence and no signs of malignancy in the 6 months after the surgical excision. CONCLUSION: Our findings indicate that a spiradenoma should be completely excised surgically because of malignant transformation after repeated recurrences.

Inducing Melanoma Cell Apoptosis by ERp57/PDIA3 Antibody in the Presence of CPI-613 and Hydroxychloroquine.

The combination of the cancer mitochondrial metabolic inhibitor CPI-613 and hydroxychloroquine has tumor-suppressive effects on clear cell sarcoma, which shares pathobiological properties with melanoma. Therefore, we intended to examine the effects of a combination of CPI-613 and hydroxychloroquine on the growth of melanoma cells in the present study. However, cell death was not induced in melanoma cells. Therefore, a monoclonal antibody, ICT, that induced apoptosis in melanoma cells in combination with CPI-613 and hydroxychloroquine was developed. Immunoprecipitation, mass spectrometry, and small interfering RNA (siRNA)-mediated gene silencing demonstrated that ICT targeted Endoplasmic Reticulum Resident Protein 57/ Protein Disulfide Isomerase Family A Member 3 (ERp57/PDIA3), which was first identified as being upregulated by metabolic depletion stress and is localized on the cell surface during immunogenic cell death. The combination of CPI-613 and hydroxychloroquine enhanced the localization of ERp57/PDIA3 to the surface of melanoma cells. siRNA-mediated downregulation of ERp57/PDIA3 did not significantly induce ICT-mediated apoptosis in melanoma cells in the presence of CPI-613 and hydroxychloroquine. Therefore, the ICT antibody acts as a tumor suppressor in melanoma cells by targeting the cell membrane ERp57/PDIA3, expression of which was enhanced by the combination of CPI-613 and hydroxychloroquine.

Expression of IZUMO2 in colorectal cancer in association with clinicopathological features.

IZUMO2 belongs to the testis-expressed IZUMO family of proteins, which are characterized by an N-terminal IZUMO domain. Based on integrated analysis of expression profiles and matched DNA methylation data from a public database, IZUMO2 represents a prognosis-related methylation-driven gene in colorectal cancer. However, it remains unclear whether IZUMO2 protein expression is suppressed or overexpressed in colorectal cancer cells. In this study, we aimed to elucidate the expression of the IZUMO2 protein in colorectal cancer, with a focus on the clinicopathological features. Sixty-four colorectal cancer tissue specimens were immunohistochemically stained using specific antibodies against IZUMO2. IZUMO2 immunoreactivity was detected at the invasion front in 30 of the 64 colorectal cancer samples. Kaplan-Meier analysis demonstrated that patients with IZUMO2 immunoreactivity had a relatively shorter overall and progression-free survival (log-rank test, P = 0.046 and 0.019, respectively). IZUMO2 immunoreactivity served as an independent factor predictive of poor progression-free survival in colorectal cancer (P = 0.025) as determined via the Cox proportional hazard regression model. Moreover, IZUMO2 immunoreactivity represented an independent factor for poor overall survival (P = 0.035) and progression-free survival (P = 0.013) in patients with colon cancer. The present findings suggest that IZUMO2 is expressed in many colorectal cancers, especially at the cancer invasion front, and may represent an indicator of poor prognosis in colorectal cancer.

Implication of IZUMO2 in the cell-in-cell phenomenon: A potential therapeutic target for triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) is characterized by the loss of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. The aggressive clinicopathological features and resistance to currently available therapeutics of the disease warrant an urgent need for the development of novel alternate therapeutic options. We have previously reported adiponectin-expressing regulatory T cells (A-Tregs), which can induce apoptosis in TNBC through the cell-in-cell phenomenon. In this study, we aimed to elucidate the molecule that allows TNBC cells to engulf A-Tregs. METHODS: A monoclonal antibody, which repressed the engulfment of A-Tregs by TNBC cells, was developed. Immunoprecipitation followed by mass spectrometry and small interfering RNAs-mediated gene silencing was performed to characterize the antigen. RESULTS: We successfully generated a monoclonal antibody, designated G1D7, which abrogated the engulfment of A-Tregs by TNBC and subsequent A-Treg-mediated apoptosis. G1D7 detected the immunoglobulin-like type I membrane protein IZUMO2, a molecule related to IZUMO1 that is essential for cell-cell membrane binding and fusion of sperm to oocyte. CONCLUSION: The findings highlight the importance of IZUMO2 on TNBC cells in facilitating the cell-in-cell phenomenon by A-Tregs.

Discrepancy in the Location of Prostate Cancer Indicated on Biparametric Magnetic Resonance Imaging and Pathologically Diagnosed Using Surgical Specimens.

Accurate diagnosis of the localization of prostate cancer (PCa) on magnetic resonance imaging (MRI) remains a challenge. We aimed to assess discrepancy between the location of PCa pathologically diagnosed using surgical specimens and lesions indicated as possible PCa by the Prostate Imaging Reporting and Data System on MRI. The primary endpoint was the concordance rate between the site of probable clinically significant PCa (csPCa) identified using biparametric MRI (bpMRI) and location of PCa in the surgical specimen obtained using robot-assisted total prostatectomy. Among 85 lesions identified in 30 patients; 42 (49.4%) were identified as possible PCa on MRI. The 85 PCa lesions were divided into positive and negative groups based on the bpMRI results. None of the patients had missed csPCa. Although the diagnostic accuracy of bpMRI was relatively high for PCas located in the middle of the prostate (p = 0.029), it was relatively low for PCa located at the base of the prostate, all of which were csPCas. Although current modalities can accurately diagnose PCa, the possibility that PCa is present with multiple lesions in the prostate should be considered, even if MRI does not detect PCa.

Successful R0 resection after chemotherapy, including nivolumab, for gastric cancer with liver metastases: three case reports.

BACKGROUND: Advances in chemotherapy have increased clinical experience with conversion surgery for inoperable advanced gastric cancer. This report describes three patients with unresectable gastric cancer accompanied by multiple liver metastases. In all three patients, nivolumab resolved the liver metastases and subsequent conversion surgery achieved a pathological complete response. CASE PRESENTATION: In Case 1, a 68-year-old man with clinical Stage IVB gastric cancer and multiple liver metastases initiated first-line therapy with SOX plus nivolumab. The patient completed 13 cycles; however, only nivolumab was continued for 3 cycles because of adverse events. Distal gastrectomy and partial hepatic resection were performed because of a significant reduction in the size of the liver metastases as observed on magnetic resonance imaging (MRI). In Case 2, a 72-year-old man with clinical Stage IVB gastric cancer and multiple liver metastases initiated first-line therapy with SOX. Because of the subsequent emergence of new liver metastases, the patient transitioned to ramucirumab plus paclitaxel as second-line therapy. Third-line therapy with nivolumab was initiated because of side effects. MRI revealed necrosis within the liver metastasis, and the patient underwent proximal gastrectomy and partial hepatectomy. In Case 3, a 51-year-old woman with clinical Stage IVB gastric cancer accompanied by multiple metastases of the liver and para-aortic lymph nodes began first-line therapy with SOX plus nivolumab. The patient completed 10 cycles; however, only nivolumab was continued for 5 cycles because of adverse events. Computed tomography showed a significant decrease in the size of the para-aortic lymph nodes, while MRI indicated the presence of a singular liver metastasis. Distal gastrectomy and partial hepatic resection were subsequently performed. In all three cases, MRI revealed the presence of liver metastases; however, pathological examination showed no viable tumor cells. CONCLUSIONS: We herein present three cases in which chemotherapy, including nivolumab, elicited a response in patients with multiple unresectable liver metastases, ultimately culminating in R0 resection through conversion surgery. Although MRI showed liver metastases, pathological analysis revealed no cancer, underscoring the beneficial impact of chemotherapy.

Experimental model of micronodular thymic neoplasm with lymphoid stroma.

BACKGROUND: Micronodular thymic neoplasm with lymphoid stroma (MNT), a subtype of thymic tumor, is histopathologically characterized by micronodular thymic epithelial cell nests with lymphoid stroma. Despite the distinct histopathology of MNT, its pathogenesis remains unclear. METHODS: In this study, we aimed to examine a thymic tumor harboring thymic epithelial and lymphoid cells in a nonobese diabetic/severe combined immunodeficiency mouse. RESULTS: The excised tumor cells were cultured in vitro and comprised epithelial tumor cells and lymphoid cells. During a three-dimensional cell culture, the epithelial tumor cells formed micronodular cell nests surrounded by lymphoid stroma. Notably, the lymphoid cells underwent apoptosis when they were separated from the epithelial tumor cells. Cutaneous transplantation of the cultured epithelial cells with splenocytes from BALB/c mice led to tumor formation, and these cells demonstrated a histopathology similar to that of human MNT in a nonobese diabetic/severe combined immunodeficiency mouse. CONCLUSION: Given its overlapping features with human MNT, the transplanted tumor could serve as an experimental model of this disease.

Adiponectin-expressing Treg-containing T cell fraction inhibits tumor growth in orthotopically implanted triple-negative breast cancer.

BACKGROUND: In our previous study, we identified a population of adiponectin expressing regulatory T cells (Tregs) residing within thymic nurse cell complexes, which were capable of inhibiting the development of breast cancer in vitro. Triple-negative breast cancer (TNBC) with no proper treatment at present is characterized by the absence of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2. In this study, we aimed to investigate the potential of a cultured T cell fraction comprising adiponectin-expressing Tregs, referred to as A-TregTF (adiponectin-expressing Treg-containing T cell fraction), in inhibiting the progression of TNBC in vivo. METHODS: The efficacy of a spontaneously expanding T cell fraction comprising adiponectin-expressing Treg in inhibiting tumor growth was analyzed in a murine orthotopic 4 T1-Luc TNBC model. RESULTS: The treatment with T cell fraction containing adiponectin-expressing Tregs significantly inhibited the growth and metastasis of orthotopically transplanted 4 T1-Luc tumor cells. Histopathological examination further revealed that the adiponectin-expressing Tregs infiltrated the tumor tissue via a cell-in-cell mechanism and were found to be specifically localized around the necrotic areas. CONCLUSIONS: Based on our findings, the T cell fraction comprising adiponectin-expressing Tregs, represents a potential candidate for adoptive cell therapy against TNBC.

Potential activity of adiponectin-expressing regulatory T cells against triple-negative breast cancer cells through the cell-in-cell phenomenon.

BACKGROUND: A population of regulatory T cells (Treg), which reside within thymic nurse cell complexes, express adiponectin and abrogate breast cancer development in transgenic mice. In this study, we examined whether adiponectin-expressing Treg could impair triple-negative breast cancer, which is defined by a lack of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor-2. METHODS: CD4- and CD25-positive cells were sorted from cultured T lymphocytes of a previously characterized experimental thymic tumor model composed of thymic nurse cells and abundant lymphoid stroma. These sorted cells were examined for FOXP3 and adiponectin immunoreactivity and subsequently exposed to triple-negative breast cancer MDA-MB-157 and -231 cells. RESULTS: Adiponectin-expressing Treg were obtained by CD4- and CD25-positive sorting and cell death was induced in triple-negative breast cancer cells through the cell-in-cell phenomenon. CONCLUSIONS: Adiponectin-expressing Treg may be candidates for adoptive cell therapy against triple-negative breast cancer.