Upregulation of S100A10 in metastasized breast cancer stem cells.

Metastatic progression remains the major cause of death in human breast cancer. Cancer cells with cancer stem cell (CSC) properties drive initiation and growth of metastases at distant sites. We have previously established the breast cancer patient-derived tumor xenograft (PDX) mouse model in which CSC marker CD44+ cancer cells formed spontaneous microscopic metastases in the liver. In this PDX mouse, the expression levels of S100A10 and its family proteins were much higher in the CD44+ cancer cells metastasized to the liver than those at the primary site. Knockdown of S100A10 in breast cancer cells suppressed and overexpression of S100A10 in breast cancer PDX cells enhanced their invasion abilities and 3D organoid formation capacities in vitro. Mechanistically, S100A10 regulated the matrix metalloproteinase activity and the expression levels of stem cell-related genes. Finally, constitutive knockdown of S100A10 significantly reduced their metastatic ability to the liver in vivo. These findings suggest that S100A10 functions as a metastasis promoter of breast CSCs by conferring both invasion ability and CSC properties in breast cancers.

Physical activity among patients with breast cancer receiving aromatase inhibitors is associated with bone health: a cross-sectional observational study.

PURPOSE: To examine the association of physical activity (PA) with bone health among patients with breast cancer receiving adjuvant aromatase inhibitor (AI) treatment. METHODS: In this single-center observational study, we enrolled postmenopausal women with primary hormone receptor-positive breast cancer who were receiving adjuvant AI treatment. We assessed patient bone health [bone mineral density (BMD) and biomarkers of bone turnover] as main outcomes. PA was assessed using Baecke physical activity questionnaires (BPAQ) and an accelerometer. Multiple regression analysis was performed after adjustment for age, body mass index, smoking history and duration of AI treatment. For missing data, multiple imputation analysis was adapted. RESULTS: The mean age of the 53 enrolled patients was 67.4 ± 8.4 years. The mean duration of AI administration was 25.7 ± 18.9 months. The most frequently administered AI was anastrozole (73.6%). Although not related to BMD, PA was related to bone turnover. Serum collagen type I amino-terminal propeptide, a bone formation marker, was associated with only light PA (t = - 2.55, p = 0.015), while tartrate-resistant acid phosphatase 5b, a bone absorption marker, was associated with work index in the BPAQ subscale and light PA (t = - 2.28, p = 0.028, t = - 2.26, p = 0.031, respectively). The results for all patients were similar to those observed in the multiple imputation analysis. CONCLUSION: PA was significantly associated with bone turnover among cancer patients receiving AI treatment. Light PA and PA in the work domain were the most important factors among various PA intensities and PA domains.

Expression of programmed death-1 in sentinel lymph nodes of breast cancer.

BACKGROUND AND OBJECTIVES: To explore whether lymphocytes in sentinel lymph nodes (SLNs) are highly exposed to tumor neoantigens and thus express high level of programmed death 1 (PD-1), we examined PD-1 expression in SLNs and non-sentinel regional lymph nodes (non-SLNs) in breast cancer. METHODS: We performed PD-1 immunohistochemistry in two cohorts: 40 metastasis-negative SLNs including 10 patients for each subtype (luminal A-like, luminal B-like, HER2, and triple negative breast cancer [TNBC]); and 25 pairs of metastasis-positive SLNs and non-SLNs (10 luminal A-like, 10 luminal B-like, and 5 TNBC). RESULTS: Among 40 metastasis-negative SLNs, 34 and 6 samples were PD-1 intensity grade 1 (low) and 2 (high), respectively. PD-1 intensity correlated with PD-1-positive lymphocyte numbers (P = 0.005); TNBC had the highest PD-1 lymphocyte numbers among all subtypes. The median PD-1-positive lymphocyte number was higher in SLNs than non-SLNs. In most cases, more lymphocytes in SLNs expressed PD-1 than those in non-SLNs (P < 0.0001). CONCLUSIONS: TNBC had the greatest PD-1 expression among all subtypes, and metastasis-positive SLNs had more PD-1-positive lymphocytes than downstream non-SLNs. These data suggested that lymphocytes in SLNs are activated following exposure to tumor neoantigens and thus tumor specific, and could be utilized as a biomarker platform.

Differences in elongation of very long chain fatty acids and fatty acid metabolism between triple-negative and hormone receptor-positive breast cancer.

BACKGROUND: Triple-negative breast cancer (TN) is more aggressive than other subtypes of breast cancer and has a lower survival rate. Furthermore, detailed biological information about the disease is lacking. This study investigated characteristics of metabolic pathways in TN. METHODS: We performed the metabolome analysis of 74 breast cancer tissues and the corresponding normal breast tissues using LC/MS. Furthermore, we classified the breast cancer tissues into ER-positive, PgR-positive, HER2-negative breast cancer (EP+H-) and TN, and then the differences in their metabolic pathways were investigated. The RT-PCR and immunostaining were carried out to examine the expression of ELOVL1, 2, 3, 4, 5, 6, and 7. RESULTS: We identified 142 of hydrophilic metabolites and 278 of hydrophobic lipid metabolites in breast tissues. We found the differences between breast cancer and normal breast tissues in choline metabolism, glutamine metabolism, lipid metabolism, and so on. Most characteristic of comparison between EP+H- and TN were differences in fatty acid metabolism was which were related to the elongation of very long chain fatty acids were detected between TN and EP+H-. Real-time RT-PCR showed that the mRNA expression levels of ELOVL1, 5, and 6 were significantly upregulated by 8.5-, 4.6- and 7.0-fold, respectively, in the TN tumors compared with their levels in the corresponding normal breast tissue samples. Similarly, the mRNA expression levels of ELOVL1, 5, and 6 were also significantly higher in the EP+H- tissues than in the corresponding normal breast tissues (by 4.9-, 3.4-, and 2.1-fold, respectively). The mRNA expression level of ELOVL6 was 2.6-fold higher in the TN tumors than in the EP+H- tumors. During immunostaining, the TN and EP+H- tumors demonstrated stronger ELOVL1 and 6 staining than the corresponding normal breast tissues, but ELOVL5 was not stained strongly in the TN or EP+H- tumors. Furthermore, the TN tumors exhibited stronger ELOVL1 and 6 staining than the EP+H- tumors. CONCLUSIONS: Marked differences in fatty acid metabolism pathways, including those related to ELOVL1 and 6, were detected between TN and EP+H-, and it was suggested that ELOVL1 and 6-related fatty acid metabolism pathways may be targets for therapies against TN.

Risk factors for joint symptoms in postmenopausal Japanese breast cancer patients treated with anastrozole: a prospective multicenter cohort study of patient-reported outcomes.

BACKGROUND: Endocrine treatment-related adverse events have a strong impact on patients' quality of life and sometimes result in treatment discontinuation. Since joint symptoms are the most frequently recognized side effect of aromatase inhibitors, evaluation of associated risk factors may yield significant findings. PATIENTS AND METHODS: A total of 391 postmenopausal Japanese women with estrogen receptor-positive breast cancer and treated with adjuvant anastrozole were enrolled from 28 centers for assessment of patient-reported outcomes (PROs) in this prospective cohort study (SAVS-JP, UMIN000002455). Patients completed the self-report questionnaire at baseline and after 3, 6, 9, and 12 months of treatment for evaluation of frequency of treatment-related joint symptoms (arthralgia, decrease in range of joint motion, and joint stiffness). RESULTS: We obtained PROs from 362 patients (92.6 %) at baseline and at one or more subsequent points. New or worsening from baseline of joint symptoms were reported by 260 patients (71.8 %). More than 90 % of the symptoms were mild or moderate and nearly 80 % had occurred by 6 months. Multivariate analysis showed that a short time span after menopause [odds ratio (OR) 0.95, 95 % confidence interval (CI) 0.90-0.99; P = 0.02] and adjuvant chemotherapy (OR 2.29, 95 % CI 1.06-4.95; P = 0.03) were significant independent risk factors for joint symptoms. No significant relationships between body mass index (BMI) and joint symptoms were identified. Eighteen patients discontinued treatment during the 1st year and eight of them reported joint symptoms. CONCLUSION: Taking into consideration that PROs may yield higher prevalence rates than physician ratings for symptoms published in pivotal clinical trials, we found that a short time span after menopause and use of adjuvant chemotherapy, but not high BMI, were significantly associated with joint symptoms. These findings might prove useful for counseling before initiating treatment with adjuvant aromatase inhibitors in postmenopausal Japanese women.

Absence of primary cilia in cell cycle-arrested human breast cancer cells.

Previous studies using cultured cells showed that primary cilia are present in quiescent cells, but are absent in proliferating cells. We studied here the relationship between the presence or absence of primary cilia and the cell cycle arrest of normal epithelial cells and cancer cells in the human normal breast and breast cancer tissues. In normal breast tissues, although most epithelial cells were nonproliferating as estimated by the immunofluorescence staining of the proliferation marker Ki-67, primary cilia were present only in 20-40% of the epithelial cells. In breast cancer tissues, primary cilia were not observed in any of the breast cancer cells. Furthermore, primary cilia were hardly observed in the nonproliferating cancer cells in the orthotopic and metastatic human breast cancer xenograft tumors in mice. These results indicate that the absence of primary cilia does not necessarily represent the proliferating phases of normal epithelial cells and cancer cells.

[Effect of Natural Killer Cell Infiltration on the Growth of Breast Cancer Patient-Derived Tumor Xenografts].

Natural killer (NK) cells, a component of the innate immunity, play important roles in tumor suppression. In this study, three human breast cancer patient-derived tumor xenografts (PDXs), established by the transplantation of surgical specimens, were passaged in immunodeficient NOD/SCID mice or NSG mice, that further lacks NK cell activity. The intensity of the relative growth suppression between NOD/SCID and NSG mice was clearly different depending on the PDX lines, and it was associated with the intensities of the CD49b-positive NK cell infiltration in the PDX tumor tissues. However, no obvious association was observed between the mRNA expression levels of the NK cell ligands in the PDX tumor cells and the intensity of NK cell infiltration into the PDX tumors. These results suggest that the suppressive effect of NK cells on the growth of breast cancer PDX is highly variable depending on the PDX lines. Further studies are needed to elucidate the molecular mechanism of NK cell infiltration in PDX tumors.

High Frequency of BRCA2 c.5576_5579del Carriers in Kakogawa, Japan.

Background/Aim: Certain germline pathogenic variants (PVs), known as founder mutations, have been frequently observed in specific regions and ethnic groups. In Japan, several pathogenic variants of BRCA1/2 have been identified as founder mutations, with their distribution varying across different regions. This retrospective study aimed to further investigate the detailed distribution and correlation between genotype and clinical features among breast cancer patients. Patients and Methods: This study was conducted at Kobe University Hospital and three collaborating institutions. It included breast cancer patients who underwent BRCA1/2 genetic testing between July 1, 2018, and March 31, 2021, and were found to have germline PVs. Clinical characteristics and breast cancer subtypes were compared between carriers of BRCA2 c.5576_5579del and those with other PVs. Additionally, the detection rate of BRCA2 c.5576_5579del was compared with that observed in a previous report. Results: A total of 38 breast cancer patients were included; PVs in BRCA1 and BRCA2 were detected in 12 and 26 patients, respectively, 12 of whom were BRCA2 c.5576_5579del carriers. BRCA2 c.5576_5579del carriers were more likely to develop triple negative breast cancers among all BRCA2 PV carriers. BRCA2 c.5576_5579del accounted for 30.8% of the PVs detected, with a particularly high frequency of 72.7% at Kakogawa Central City Hospital. Conclusion: BRCA2 c.5576_5579del was detected with a particularly high frequency in Hyogo Prefecture, especially in Kakogawa city. In the future, a survey of the distribution of the BRCA2 c.5576_5579del carriers may provide more clarity regarding their localization.

Adipsin-Dependent Secretion of Hepatocyte Growth Factor Regulates the Adipocyte-Cancer Stem Cell Interaction.

Adipose tissue is a component of the tumor microenvironment and is involved in tumor progression. We have previously shown that adipokine adipsin (CFD) functions as an enhancer of tumor proliferation and cancer stem cell (CSC) properties in breast cancers. We established the Cfd-knockout (KO) mice and the mammary adipose tissue-derived stem cells (mADSCs) from them. Cfd-KO in mADSCs significantly reduced their ability to enhance tumorsphere formation of breast cancer patient-derived xenograft (PDX) cells, which was restored by the addition of Cfd in the culture medium. Hepatocyte growth factor (HGF) was expressed and secreted from mADSCs in a Cfd-dependent manner. HGF rescued the reduced ability of Cfd-KO mADSCs to promote tumorsphere formation in vitro and tumor formation in vivo by breast cancer PDX cells. These results suggest that HGF is a downstream effector of Cfd in mADSCs that enhances the CSC properties in breast cancers.

Adipose-derived stem cells enhance human breast cancer growth and cancer stem cell-like properties through adipsin.

Tumor microenvironment plays a key role for tumor development and progression. Although adipose tissue is a predominant component of stroma in mammary tissues and secretes various cytokines, chemokines and growth factors, roles of adipocytes in breast cancers remain to be elucidated. In this study, we found that adipsin, an adipokine secreted from mammary adipose tissues, enhanced proliferation and cancer stem cell (CSC)-like properties of human breast cancer patient-derived xenograft (PDX) cells. Adipsin was predominantly expressed in both adipose tissues of the surgical specimens of breast cancer patients and adipose-derived stem cells (ADSCs) isolated from them, and its expression level was significantly higher in obese patients. ADSCs significantly enhanced the sphere-forming ability of breast cancer PDX cells derived from both estrogen receptor-positive and -negative breast cancer PDX cells. Suppression of adipsin-mediated signaling by a specific inhibitor or adipsin knockdown in ADSCs significantly decreased the sphere-forming ability and the expression of CSC markers in co-cultured breast cancer PDX cells. Growth of breast cancer PDX tumors was significantly enhanced by co-transplantation with ADSCs in vivo, and it was weakened when co-transplanted with the adipsin knocked-down ADSCs. These results suggest that adipsin is an important adipokine secreted from mammary adipose tissue that functions as a component of tumor microenvironment and a CSC niche in breast cancers.

Nipple adenoma found in a mastectomy specimen: report of a case with special regard to the proliferation pattern.

We report a case of nipple adenoma incidentally found in a mastectomy specimen, and describe its unique histological appearance and the immunohistochemical distribution of Ki-67 positive tumor cells. A 45-year-old woman with no symptoms or sign related to the nipple had a left mastectomy for invasive breast cancer. A small nipple adenoma, 7 mm in size, was incidentally recognized in the nipple of the resected breast. Histologically, the tumor in the nipple was composed of numerous proliferative ducts with a tubular and florid papillomatous appearance. Many demarcations between squamous cells of the epidermis and tumor cells were recognized in the summit as well as the lateral wall of the nipple. A high Ki-67 labeling index (20.3%) was recognized in the tumor cells in the superficial region, and a low labeling index (0.7%) was seen in the deeper region of the tumor. Based on these proliferative patterns, the symptoms and clinical signs related to the nipple that are often found in patients with nipple adenoma are thought to be associated with the destruction of the epidermis of the nipple by the invasion of benign tumor cells with high proliferative activity.

Effectiveness of Pertuzumab, Trastuzumab, and Docetaxel Combination Neoadjuvant Chemotherapy for HER2-Positive Inflammatory Breast Cancer: A Case Report.

BACKGROUND: Inflammatory breast cancer (IBC) is the most aggressive form of primary breast cancer. CASE REPORT: A 40-year-old woman was referred to our hospital for evaluation of an induration in the right breast, suspected to be breast cancer. The tumor was diagnosed as estrogen receptor-negative, progesterone receptor-negative, HER2-positive, T4dN3cM0 stage IIIc IBC with axillary lymph node metastasis. Rather than surgical intervention, we chose a systemic treatment approach with pertuzumab, trastuzumab, and docetaxel (PTD) combination therapy which was shown to be effective for HER2-positive IBC in the NeoSphere trial. After 4 cycles of treatment, the patient had a partial response, allowing mastectomy of the right breast and axillary lymph node dissection to achieve local control. We review this case because of the success of PTD combination neoadjuvant chemotherapy for HER2-positive IBC. CONCLUSION: To improve the poor prognosis of IBC, combined modality therapy is required, including chemotherapy and local treatment such as surgery and/or radiation therapy. In this case, combination neoadjuvant chemotherapy with PTD for HER2-positive IBC was effective, and this regimen may contribute to further improvements in the cure rate for this malignancy.

Body mass index and menopausal disorders during menopause affect vasomotor symptoms of postmenopausal Japanese breast cancer patients treated with anastrozole: a prospective multicenter cohort study of patient-reported outcomes.

BACKGROUND: Adverse events related to endocrine therapies have a major impact not only on patients' quality of life but also on treatment discontinuation. Although vasomotor symptoms induced by aromatase inhibitors are frequently recognized, risk factors, especially for Japanese women, are not well reported. To identify risk factors for vasomotor symptoms of Japanese breast cancer patients treated with adjuvant anastrozole, we conducted a prospective cohort study based on patient-reported outcomes (PROs). PATIENTS AND METHODS: For this prospective cohort study (SAVS-JP, UMIN000002455), 391 postmenopausal Japanese estrogen receptor-positive breast cancer patients who were treated with adjuvant anastrozole were recruited from 28 centers. The PRO assessment was obtained from a self-reported questionnaire at baseline, 3, 6, 9 and 12 months between August 2009 and April 2012. Vasomotor symptoms, comprising hot flashes, night sweats, and cold sweats, were categorized into four grades (none, Grade 1: mild, Grade 2: moderate, Grade 3: severe). Pre-existing symptoms were only included if they had become worse than at baseline. RESULTS: Hot flashes, night sweats, and cold sweats at baseline were reported by 20.5, 15.1, and 8.2 % of the patients, respectively, and new appearance or worsening of symptoms in comparison with baseline by 38.4, 29.3, and 28.7 %, respectively. About 80 % of newly occurring symptoms were Grade 1, and less than 5 % were Grade 3. Vasomotor symptoms were reported by 201 out of 362 patients (55.5 %) during the first year and the mean time to onset was 5.6 months. Patients with vasomotor symptoms were significantly younger (mean 62.8 years, range 38-86 vs 64.7 years, range 37-84; p = 0.02), had higher body mass index (BMI) (23.4 kg/m2, range 15.8-39.9 vs 22.4 kg/m2, range 15.8-34.9; p = 0.01), had vasomotor symptoms sooner after menopause (12.4 years, range 0-51 vs 15.1 years, range 1-37; p = 0.002), and had more menopausal disorders during menopause (63.3 vs 36.7 %; p = 0.002). Multivariate analysis showed that BMI [odds ratio (OR) 1.09 per unit of increase, 95 % confidence interval (CI) 1.02-1.16; p = 0.009] and experiencing menopausal disorders (OR 2.11, 95 % CI 1.35-3.30; p = 0.001) were significantly associated with vasomotor symptoms. CONCLUSION: High BMI and experiencing menopausal disorders at menopause were found to be significantly associated with the occurrence of vasomotor symptoms. These findings are expected to prove useful for the management of postmenopausal Japanese women treated with aromatase inhibitors.

Comparison of 2D- and 3D-culture models as drug-testing platforms in breast cancer.

It is becoming recognized that screening of oncology drugs on a platform using two-dimensionally (2D)-cultured cell lines is unable to precisely select clinically active drugs; therefore three-dimensional (3D)-culture systems are emerging and show potential for better simulating the in vivo tumor microenvironment. The purpose of this study was to reveal the differential effects of chemotherapeutic drugs between 2D- and 3D-cultures and to explore their underlying mechanisms. We evaluated differences between 2D- and 3D-cultured breast cancer cell lines by assessing drug sensitivity, oxygen status and expression of Ki-67 and caspases. Three cell lines (BT-549, BT-474 and T-47D) developed dense multicellular spheroids (MCSs) in 3D-culture, and showed greater resistance to paclitaxel and doxorubicin compared to the 2D-cultured cells. An additional three cell lines (MCF-7, HCC-1954, and MDA-MB­231) developed only loose MCSs in 3D, and showed drug sensitivities similar to those found in the 2D-culture. Treatment with paclitaxel resulted in greater increases in cleaved-PARP expression in the 2D-culture compared with the 3D-culture, but only in cell lines forming dense 3D-MCSs, suggesting that MCS formation protected the cells from paclitaxel-induced apoptosis. Hypoxia was observed only in the dense 3D-MCSs. BT-549 had fewer cells positive for Ki-67 in 3D- than in 2D-culture, suggesting that the greater G0-dormant subpopulation was responsible for its drug resistance in the 3D-culture. BT-474 had a lower level of caspase-3 in the 3D- than in the 2D-culture, suggesting that the 3D-environment was anti-apoptotic. Finally, we compared staining for Ki-67 and caspases in the 2D- and 3D-primary­cultured cells originating from a patient-derived xenograft (PDX), fresh PDX tumor, and the patient's original tumor; 2D-cultured cells showed greater proportions of Ki-67-positive and caspase-3-positive cells, in agreement with the view that 3D-primary culture better represents characteristics of tumors in vivo. In conclusion, 3D-cultured cells forming dense MCSs may be better than 2D-cultured cells in simulating important tumor characteristics in vivo, namely hypoxia, dormancy, anti-apoptotic features and their resulting drug resistance.

Predictive factors for anthracycline-based chemotherapy for human breast cancer.

Predictive factors for anthracycline-based chemotherapy have yet to be incorporated into daily practice. Meta-analyses of studies using anthracycline-based treatment regimens have shown an improved prognosis for human epidermal growth factor receptor type 2 (HER2)-positive tumors, but not for HER2-negative tumors compared with results of non-anthracycline regimens. Currently it is believed that the positive association between HER2 status and anthracycline sensitivity is indirect, that is, their association may be mediated through topoisomerase II alpha (TOP2A), a target molecule of anthracyclines, since TOP2A is near HER-2 and co-amplification of the TOP2A gene frequently occurs in HER2-amplified tumors. This strongly suggests that TOP2A gene amplification is a predictive factor for anthracyline-based regimens. The Collaborative Study Group of Scientific Research of the Japanese Breast Cancer Society has demonstrated that TOP2A-positive and BRCA1-negative subsets evaluated by immunohistochemical staining show a significantly higher pathological complete response when treated with preoperative epirubicin-containing regimens. Combining these findings with the observation that triple-negative tumors and basal-like tumors respond to anthracycline treatment suggests that not only HER2-positive tumors but also a distinct subset of HER2-negative tumors may be sensitive to anthracycline-based regimens.

Immunohistochemical study of the relationship between Ki-67 labeling index of proliferating cells of gynecomastia, histological phase and duration of disease.

Gynecomastia is a benign proliferative lesion caused by various etiological factors and may result from a relative imbalance between serum estrogen and androgen levels. The histological alterations are similar, and gynecomastia can progress from a florid type to a fibrous type. The Ki-67 labeling index (LI) of gynecomastia specimen was investigated and higher Ki-67 LI was observed in florid and intermediate than in fibrous gynecomastia (P = 0.017). A correlation was found between the duration of disease and Ki-67 LI (P = 0.041): the shorter the duration the higher the Ki-67 LI. Thus, Ki-67 LI seems a useful tool to examine proliferation activity of gynecomastia and can assist in determination of appropriate treatment of gynecomastia with hormonal therapy.

Histochemical, immunohistochemical, and ultrastructural studies of gingival fibromatosis: a case report.

Gingival fibromatosis is a rare disease characterized by enlargement of the gingiva. The purpose of this study was to analyze a case of idiopathic gingival fibromatosis, using histochemical and immunohistochemical staining and transmission electron microscopy. The patient was a 39-year-old Japanese man, in whom the gingiva was enlarged throughout the entire mandible and maxilla. Specimens of gingival fibromatosis exhibited epithelial hyperplasia and increased amounts of collagen fiber bundles in the connective tissue light-microscopically. Well-developed collagen bundles were strongly stained with Azan and Masson trichrome staining. Immunohistochemically, the gingival connective tissue was specifically stained by type I collagen and vimentin antibodies. Ultrastructurally, the lesion consisted of fibroblasts and mature collagen fibers running in all directions. No myofibroblasts were detected histochemically, immunohistochemically, or ultrastructurally. These findings suggested that this disease may be the result of an increase in collagen synthesis by the fibroblasts and/or that it may be associated with one of the findings of histologic heterogeneity.