Claudin-4-adhesion signaling drives breast cancer metabolism and progression via liver X receptor ß.

BACKGROUND: Cell adhesion is indispensable for appropriate tissue architecture and function in multicellular organisms. Besides maintaining tissue integrity, cell adhesion molecules, including tight-junction proteins claudins (CLDNs), exhibit the signaling abilities to control a variety of physiological and pathological processes. However, it is still fragmentary how cell adhesion signaling accesses the nucleus and regulates gene expression. METHODS: By generating a number of knockout and rescued human breast cell lines and comparing their phenotypes, we determined whether and how CLDN4 affected breast cancer progression in vitro and in vivo. We also identified by RNA sequencing downstream genes whose expression was altered by CLDN4-adhesion signaling. Additionally, we analyzed by RT-qPCR the CLDN4-regulating genes by using a series of knockout and add-back cell lines. Moreover, by immunohistochemistry and semi-quantification, we verified the clinicopathological significance of CLDN4 and the nuclear receptor LXRß (liver X receptor ß) expression in breast cancer tissues from 187 patients. RESULTS: We uncovered that the CLDN4-adhesion signaling accelerated breast cancer metabolism and progression via LXRß. The second extracellular domain and the carboxy-terminal Y197 of CLDN4 were required to activate Src-family kinases (SFKs) and the downstream AKT in breast cancer cells to promote their proliferation. Knockout and rescue experiments revealed that the CLDN4 signaling targets the AKT phosphorylation site S432 in LXRß, leading to enhanced cell proliferation, migration, and tumor growth, as well as cholesterol homeostasis and fatty acid metabolism, in breast cancer cells. In addition, RT-qPCR analysis showed the CLDN4-regulated genes are classified into at least six groups according to distinct LXRß- and LXRßS432-dependence. Furthermore, among triple-negative breast cancer subjects, the "CLDN4-high/LXRß-high" and "CLDN4-low and/or LXRß-low" groups appeared to exhibit poor outcomes and relatively favorable prognoses, respectively. CONCLUSIONS: The identification of this machinery highlights a link between cell adhesion and transcription factor signalings to promote metabolic and progressive processes of malignant tumors and possibly to coordinate diverse physiological and pathological events.

The relationship between BRCA-associated breast cancer and age factors: an analysis of the Japanese HBOC consortium database.

BRCA1/2 pathogenic variant prevalence in Japanese breast cancer is unclear. Here, we analyzed BRCA1/2 pathogenic variant prevalence with a particular focus on age factors, using the Japanese HBOC consortium database. All registered subjects were Japanese individuals who underwent BRCA1/2 genetic testing from January 1996 to July 2017 according to the Japanese HBOC consortium database. Cases were extracted and analyzed for each evaluation item. Overall BRCA1 and BRCA2 pathogenic variant prevalence was 11.2% and 9.0% in the cohort of 2366 proband patients, respectively. The age at onset of breast cancer for patients with BRCA1/2 pathogenic variants was significantly lower than that for patients without a BRCA1/2 pathogenic variant. In both BRCA1/2 patients, ages at onset were not statistically significantly different between two subtype groups (ER-positive vs. TNBC). We analyzed the BRCA1/2 pathogenic variant prevalence among age groups in patients with no family history of breast or ovarian cancer. In the TNBC group, the rate of genetic variants was more frequent among younger patients. Our results demonstrated that early breast cancer onset is associated with a BRCA1/2 pathogenic variant in the Japanese population. Younger TNBC patients were more likely to have a BRCA1/2 pathogenic variant irrespective of a family history of breast or ovarian cancer.

[A Case of Emergency Radiotherapy for Intramedullary Spinal Cord Metastasis from Breast Cancer].

Intramedullary spinal cord metastasis(ISCM)is rare. However, with advances in diagnostic imaging, the incidence of ISCM is increasing. We herein present a case of breast cancer metastasis in the lower thoracic spinal intramedullary area in a patient who was then successfully treated with emergency radiotherapy. A 56‒year‒old woman with breast cancer was admitted to our hospital due to rapidly progressing weakness in both legs and bladder and rectal disturbance. Spinal MRI revealed a gadolinium‒enhancing intramedullary lesion. The patient was treated with emergency radiotherapy and oral steroids. Although the prognosis of ISCM is extremely poor, emergency radiotherapy could be an effective treatment for ISCM to improve the patient's quality of life(QOL).

[A Case Report of Uterine Metastasis Four Years after Breast Surgery for Breast Cancer].

We report a case of uterine metastasis of the breast cancer. The patient was diagnosed with invasive ductal carcinoma of the breast and underwent partial right mastectomy and sentinel lymph node biopsy. Tamoxifen was administered as adjuvant endocrine therapy. Four years after the surgery, she had irregular genital bleeding, and was referred to our hospital for cytological diagnosis of uterine cancer. Postoperative pathological diagnosis showed uterine metastasis of breast cancer, and it was decided to treat the recurrence of breast cancer with aromatase inhibitors and CDK4/6 inhibitors, a molecular targeted therapy. The patient has been progression-free for 5 months.

Triple-Negative Breast Cancer with High Levels of Annexin A1 Expression Is Associated with Mast Cell Infiltration, Inflammation, and Angiogenesis.

Annexin A1 (ANXA1) is a phospholipid-linked protein involved in inflammation, immune response, and mast cell reactivity. Recently, we reported that ANXA1 is associated with aggressive features of triple-negative breast cancer (TNBC); however, its clinical relevance remains controversial. We hypothesized that human TNBC with high expression of ANXA1 mRNA is associated with pro-cancerous immune cell infiltration, including mast cells, and with an aggressive phenotype. Clinical and RNA-seq data were obtained from The Cancer Genome Atlas (TCGA, n = 1079) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) (n = 1904). TNBC patients had significantly higher levels of ANXA1 expression compared to the other subtypes in both TCGA and METABRIC cohorts (p < 0.001). ANXA1 protein expression was assessed by immunohistochemistry in Japanese TNBC patient cohort (n = 48), where 17 cases (35.4%) had positive ANXA1 staining, and their overall survival was significantly shorter compared with negative staining group (p = 0.008). The CIBERSORT algorithm was used to calculate immune cell infiltrations. ANXA1 high tumors were associated with activated mast cells and M2 macrophages (p > 0.01), but did not show any association with tumor heterogeneity nor cytolytic activity. High expression of ANXA1 group enriched inflammation, epithelial-to-mesenchymal transition (EMT), and angiogenesis-related genes in a gene set enrichment assay in both cohorts. To our knowledge, this is the first study to demonstrate that ANXA1 is associated with infiltration of mast cells and inflammation that is associated with the aggressive phenotype of TNBC, such as EMT and angiogenesis.

[A Case of Synchronous Bilateral Neuroendocrine Ductal Carcinoma In Situ].

Neuroendocrine ductal carcinoma in situ(NE-DCIS)is a unique subtype of ductal carcinoma in situ(DCIS)that is not described in the general rules for clinical and pathological recording of breast cancer. NE-DCIS is described as an unusual variant of DCIS in the 2012 World Health Organization(WHO)classification. The chief complaint in NE-DCIS is hemorrhagic nipple discharge. The histological characteristics of NE-DCIS are solid growth of cancer cells with granular and spindle-shaped nuclei. Histologically, NE-DCIS is suggestive of low malignancy but a poor prognosis of neuroendocrine carcinoma of the breast has been reported. The report by Honami et al was the only other report of synchronous bilateral neuroendocrine ductal carcinoma in situ. We report the second case of NE-DCIS diagnosed synchronously in both breasts in a patient who had visited our outpatient clinic with hemorrhagic nipple discharge.

[Indication for Radiotherapy for Breast Cancer Metastasis to the Skull Base Accompanied by Cranial Nerve Palsies].

Distant metastasis to the skull base region frequently manifests various cranial nerve symptoms and reduces patients' quality of life(QOL). We report a 62-year-old woman with skull base metastasis of breast cancer, whose condition clinically improved following palliative radiotherapy. The patient presented to our hospital with hoarseness. CT screening revealed a tumor in the right breast, axial lymph node swelling, and osteoblastic change at multiple sites. A core needle biopsy of the breast tumor revealed invasive lobular carcinoma. She also had nausea, anorexia, vertigo, lower left angle of the mouth, apraxia of lid closing, and dysphagia owing to several cranial nerve palsies. MRI T1- and T2-weighted images showed a diffuse low-signal intensity of the skull base region, and the patient was diagnosed as having breast cancer with symptomatic skull base metastases. Her cranial nerve symptoms improved after 1 week of palliative irradiation to the skull base. We conclude that, even among terminal-stage patients, palliative radiotherapy to the skull base region is an effective treatment option to improve patients' QOL.

[A Case of Encapsulated Papillary Carcinoma of the Breast].

An 84-year-old woman was revealed to have focal asymmetric density(FAD)based on mammography, and ultrasonography showed a 0.5 cm sized cyst in the left breast. It gradually increased in size and contained solid components. A core needle biopsy revealed an intracystic papillary carcinoma of the breast. Partial mastectomy and sentinel lymph node biopsy were performed. Histopathological examination revealed an encapsulated papillary carcinoma and a papillary lesion surrounded by a thick fibrous capsule. Myoepithelial cells were not found at the periphery of the lesion or within fibrovascular cores. Currently, it is classified as non-invasive carcinoma, and the patient has a good prognosis.

Metastasis of breast cancer cells to the bone, lung, and lymph nodes promotes resistance to ionizing radiation.

BACKGROUND: Metastasis represents the leading cause of breast cancer deaths, necessitating strategies for its treatment. Although radiotherapy is employed for both primary and metastatic breast cancers, the difference in their ionizing radiation response remains incompletely understood. This study is the first to compare the radioresponse of a breast cancer cell line with its metastatic variants and report that such metastatic variants are more radioresistant. MATERIALS AND METHODS: A luciferase expressing cell line was established from human basal-like breast adenocarcinoma MDA-MB-231 and underwent in vivo selections, whereby a cycle of inoculations into the left cardiac ventricle or the mammary fat pad of athymic nude mice, isolation of metastases to the bone, lung and lymph nodes visualized with bioluminescence imaging, and expansion of obtained cells was repeated twice or three times. The established metastatic cell lines were assessed for cell proliferation, wound healing, invasion, clonogenic survival, and apoptosis. RESULTS: The established metastatic cell lines possessed an increased proliferative potential in vivo and were more chemotactic, invasive, and resistant to X­ray-induced clonogenic inactivation and apoptosis in vitro. CONCLUSION: Breast cancer metastasis to the bone, lung, and lymph nodes promotes radioresistance.

[A Case of Occult Breast Cancer].

We report a case of occult breast cancer. A 61-years-old woman underwent tumorectomy of right axillary mass. Pathological diagnosis was adenocarcinoma. Two years after, right axillary mass was discovered again. Wide local excision, axillary lymph node dissection and radiation therapy of the breast was performed. Pathological findings showed lymph node metastasis of breast cancer, or primary cancer of the axially tail of the breast. Ten months after second operation, she presented an axillary mass again. She underwent resection of the axillary tumor. The pathological findings showed lymph node metastasis of breast cancer. There was no evidence of primary tumor of the breast during the period. We suspected lymph node metastasis of occult breast cancer. Irradiation was administered to the right axilla, and she is receiving endocrine therapy.

[A Case of Breast Carcinoma Associated with Osteoclast-Like Giant Cells].

Mammary carcinoma with osteoclast-like giant cells is uncommon, and its onset mechanism and malignancy are unknown. We report a case of mammary carcinoma with osteoclast-like giant cells. A 41-year-old woman noticed a lump in her left breast. Ultrasound sonography findings suggested breast cancer. A core needle biopsy revealed invasive ductal carcinoma of the breast. Modified radicalmastectomy and sentinell ymph node biopsy were performed. Histopathologicalexamination revealed papillotubular carcinoma with osteoclast-like giant cells. Cells were positive for estrogen receptor and progesterone, and negative for HER2. MIB-1 index was under 5%. The giant cells were generally associated with an inflammatory, fibroblastic, hyper-vascular stroma. The carcinomatous part of the lesion was most frequently a well-to moderately differentiated invasive ductalcarcinoma. Immunohistochemicaland ultrastructuralstudies suggested that the osteoclast-like giant cells were of stromalhistiocytic origin. To understand biochemicalfindings of this carcinoma, more case studies are required to be reported.

[Use of Pegfilgrastim in Adjuvant and Neoadjuvant Chemotherapy for Breast Cancer].

We assessed the incidence of febrile neutropenia(FN), infection, and relative dose intensity(RDI)with or without the use of pegfilgrastim in breast cancer patients receiving adjuvant or neoadjuvant chemotherapy. Twenty-five patients received 4 cycles of FEC(5-FU 500mg/m2 plus epirubicin 100 mg/m2 plus cyclophosphamide 100 mg/m2 q3w)followed by 4 cycles of docetaxel(75mg/m2 q3w). Ten patients were administered pegfilgrastim as primary prophylaxis throughout all cycles of chemotherapy, and 15 patients were not. The rate of FN was only 7% in patients not undergoing pegfilgrastim therapy. The infection rate and RDI were not significantly different between the 2 groups, but the incidence of fever was lower in patients treated with pegfilgrastim. In patients with early stage breast cancer, the use of primary pegfilgrastim during all chemotherapy cycles should be considered a safe option.

[A Case of Primary Poorly Differentiated/Small Cell Carcinoma of the Breast in a Patient with Von Recklinghausen's Disease].

We report a case of neuroendocrine carcinoma and poorly differentiated/small cell carcinoma ofthe breast in a patient with von Recklinghausen's disease. The patient was a 46-year-old woman who was diagnosed with von Recklinghausen's disease when she was 22 years old. She presented with left breast pain, and physical examination revealed a firm mass in the left breast. A core needle biopsy of the tumor revealed triple negative breast cancer with neuroendocrine features. We performed a simple mastectomy with lymph node dissection. We did not plan neoadjuvant chemotherapy because the tumor would be possibly inoperative if neoadjuvant chemotherapy was not effective for this neuroendocrine cancer. The tumor was diagnosed as a neuroendocrine carcinoma and poorly differentiated/small cell carcinoma. The patient was treated with CDDP and CPT- 11, which is a regimen often used to treat small cell lung cancer.

[A Case of Axillary Arterial Bleeding after Axillary Metastatic Lymph Node Necrosis during Treatment with Paclitaxel and Bevacizumabfor Breast Cancer].

A 44-year-old woman was diagnosed cT4bcN3cM1(LYM), Stage IV triple-negative breast cancer.Enhanced computed tomography revealed ipsilateral axillary lymph node metastasis, 10 cm in diameter.The supraclavicular and cervical lymph nodes also had metastases.She received paclitaxel(90mg/m2, on days 1, 8, and 15 every 4 weeks)in combination with bevacizumab(10mg/kg, on days 1 and 15 every 28 days).Her height was 165 cm, and her body weight was 100 kg.After 1 course of chemotherapy, a metastatic axillary lymph node with necrotic changes was removed spontaneously.A few days later, she experienced severe bleeding from her axillary artery, and she went into hypovolemic shock.Despite undergoing surgical hemostasis, the bleeding recurred twice, so we performed coil embolization of her subclavian artery.Thirty -five days after the first occurrence of bleeding, the patient died of sepsis and ARDS due to left arm necrosis.Bevacizumab is effective for the treatment of large tumors, but when the tumor is close to an artery, clinicians should be wary of fatal bleeding after necrosis.

Pneumocystis Pneumonia in Locally Advanced Breast Cancer Despite Prophylactic Use of Trimethoprim-Sulfamethoxazole During Prednisolone Treatment for a Pembrolizumab-Induced Immune-Related Adverse Event: A Case Report.

Pneumocystis pneumonia (PCP) primarily affects immunosuppressed patients, with trimethoprim-sulfamethoxazole (TMP-SMX) commonly used for prophylaxis. However, there is insufficient information on PCP occurrence despite TMP-SMX prophylaxis. We encountered a 57-year-old woman with locally advanced breast cancer developing PCP despite prophylactic intake of TMP-SMX, during treatment with prednisolone for Stevens-Johnson syndrome (SJS) induced by pembrolizumab. This case underscores the need to pay attention to the possibility of PCP development even during TMP-SMX prophylaxis. Dosage and duration adjustments according to the patient's condition and weight may be required.

Endosomal protein expression of γ1-adaptin is associated with tumor growth activity and relapse-free survival in breast cancer.

BACKGROUND: γ1-Adaptin is a subunit of adaptor protein complex-1 (AP-1), which regulates intracellular transport between the trans-Golgi network (TGN) and endosomes. Since expression levels of AP-1 subunits have been reported to be associated with cell proliferation and cancer malignancy, we investigated the relationships between the immunohistochemical expression of γ1-adaptin and both clinicopathological factors and relapse-free survival (RFS) in breast cancer tissue. MATERIALS AND METHODS: SK-BR-3 cell line depleted of γ1-adaptin was used for cell proliferation, migration, and invasion assay. Intracellular localization of γ1-adaptin was examined with immunohistochemistry (IHC) using an antibody against γ1-adaptin, and with double immunohistofluorescence (IHF) microscopy using markers for the TGN and endosome. γ1-Adaptin intensities in IHC samples from 199 primary breast cancer patients were quantified and assessed in relation to clinicopathological factors and RFS. RESULTS: Cell growth, migration, and invasion of SK-BR-3 cells were significantly suppressed by the depletion of γ1-adaptin. Although the staining patterns in the cancer tissues varied among cases by IHC, double IHF demonstrated that γ1-adaptin was mainly localized in EEA1-positive endosomes, but not in the TGN. γ1-Adaptin intensity was significantly higher in the tumor regions than in non-tumor regions. It was also higher in patients with Ki-67 (high), ER (-), PgR (-), and HER2 (+). Among subtypes of breast cancer, γ1-adaptin intensity was higher in HER2 than in luminal A or luminal B. The results of the survival analysis indicated that high γ1-adaptin intensity was significantly associated with worse RFS, and this association was also observed in group with ER (+), PgR (+), HER2 (-), Ki-67 (high), or luminal B. In addition, the Cox proportional hazards model showed that high γ1-adaptin intensity was an independent prognostic factor. CONCLUSION: These results suggest that the endosomal expression of γ1-adaptin is positively correlated with breast cancer malignancy and could be a novel prognostic marker.

Association between specific human leukocyte antigen alleles and development of thyroid immune-related adverse event.

Aim: Inherent variations in human leukocyte antigen (HLA) alleles have been revealed epidemiologically to influence the development of autoimmune diseases. HLA alleles may thus also be associated with the development of immune-related adverse events (irAEs), such as thyroid irAE. Materials & methods: In this case-control study, 71 cancer patients who received immune checkpoint inhibitors were enrolled and HLA-genotyped and the frequency of HLA alleles was compared. Results: A*26:01, DPA1*01:03 and DPB1*02:01 were significantly more frequent in patients with thyroid irAE than in patients without any irAEs (35.0 vs 3.2% [p = 0.004], 80.0 vs 45.2% [p = 0.020] and 55.0 vs 25.8% [p = 0.044], respectively). Conclusion: A*26:01, DPA1*01:03 and DPB1*02:01 appear to be associated with thyroid irAE.

Everyone has a unique combination of human leukocyte antigens (HLAs) in their body that help the immune system identify threats. HLAs were named from the fact that they were first identified on the surface of human leukocytes. Afterward, HLAs were also found on all human cells. HLAs present antigens to immune cells. These HLAs also influence how the immune system attacks cancer cells. Immune checkpoint inhibitors are drugs that can help the immune system fight cancer, but they sometimes cause severe adverse events. In this study, we investigated whether specific HLA genes are related to the development of an adverse event that affects the thyroid in cancer patients treated with immune checkpoint inhibitors. We found an association between three HLA genes (A*26:01, DPA1*01:03 and DPB1*02:01) and the development of the thyroid adverse event. However, larger studies are needed to confirm and generalize these initial exploratory findings.

Long-term Experience on Breast Cancer-related Lymphedema in the Coastal Area of Fukushima, Japan After the 2011 Triple Disaster.

BACKGROUND/AIM: Disasters can jeopardize breast cancer care and Japan's triple disaster in 2011 (earthquake, tsunami, and nuclear accident) is no exception. However, detailed information is lacking regarding the care of breast cancer related lymphedema (BCRL) following the disaster. We aimed to explore the process by which local patients become aware of BCRL, the problems faced, and the support they require. We also aimed to clarify the effects of the 2011 disaster on experiences related to lymphedema in the target population. PATIENTS AND METHODS: Patients who developed BCRL after breast cancer treatment were recruited from Iwaki city, a municipality located in the southern coastal region of Fukushima (N=16). In-depth, semi-structured, face-to-face interviews were conducted, and the obtained data were appraised using thematic analysis. RESULTS: Five themes related to BCRL were identified: 1) the process of becoming aware of BCRL, 2) troubles or worries/concerns due to BCRL, 3) information sources regarding BCRL management, 4) strategies to cope with BCRL, and 5) the adverse impacts of the 2011 disaster on BCRL management. CONCLUSION: Except for the disaster context, the themes are in line with those of previous studies conducted in the non-disaster context. Nonetheless, there were limited but non-negligible adverse effects of the 2011 disaster on long-term local BCRL management. The findings of this study demonstrate the necessity for individualizing coping strategies against BCRL among healthcare professionals in the Fukushima coastal area and beyond.

E3 Ubiquitin Ligase NEDD4 Affects Estrogen Receptor α Expression and the Prognosis of Patients with Hormone Receptor-Positive Breast Cancer.

Neural precursor cell-expressed developmentally downregulated 4-1 (NEDD4) is an E3 ligase that leads to the degradation of proteins, including estrogen receptor α. We evaluated whether the expression level of NEDD4 affected the outcome of breast cancer patients. We performed a retrospective cohort study enrolling 143 patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative early breast cancer. Of the 66 patients with high NEDD4 mRNA levels (high NEDD4 group) and 77 patients with low NEDD4 mRNA levels (low NEDD4 group), 98.4% and 96.1%, respectively, of the patients had received neoadjuvant/adjuvant hormone therapy. Disease-free survival and overall survival were significantly longer in the low NEDD4 group than in the high NEDD4 group (p = 0.048 and p = 0.022, respectively). Western blotting revealed a high expression of estrogen receptor α in the NEDD4-knockdown culture cells. The proliferation of NEDD4-knockdown cells treated with tamoxifen or estradiol deprivation was suppressed, compared with that of NEDD4-expressing cells. Knockdown of NEDD4 in breast cancer cells induced the accumulation of estrogen receptor α and increased sensitivity to hormone therapy. In summary, this mechanism may lead to a better prognosis in hormone receptor-positive breast cancer patients with a low expression of NEDD4.

The necessity of proactive measures from healthcare providers highlighted by delayed breast cancer diagnosis due to COVID-19: A case report.

Key Clinical Message: During disasters, multiple factors can cause significant delays in medical visits. Regular patient monitoring, high-risk individual alerts, and telemedicine enhancements can potentially alleviate these issues and ensure timely interventions. Abstract: During the COVID-19 pandemic, a Japanese woman in her 70s delayed her regular breast cancer checkup for over 2 years. During disasters, health priorities tend to decline, necessitating proactive measures from healthcare providers, such as augmenting collaboration among healthcare professionals and identifying high-risk individuals.