Therapeutic advances in BIG3-PHB2 inhibition targeting the crosstalk between estrogen and growth factors in breast cancer.

Our previous studies demonstrated that specific inhibition of the BIG3-PHB2 complex, which is a critical modulator in estrogen (E2) signaling, using ERAP, a dominant negative peptide inhibitor, leads to suppression of E2-dependent estrogen receptor (ER) alpha activation through the reactivation of the tumor suppressive activity of PHB2. Here, we report that ERAP has significant suppressive effects against synergistic activation caused by the crosstalk between E2 and growth factors associated with intrinsic or acquired resistance to anti-estrogen tamoxifen in breast cancer cells. Intrinsic PHB2 released from BIG3 by ERAP effectively disrupted each interaction of membrane-associated ERα and insulin-like growth factor 1 receptor beta (IGF-1Rß), EGFR, PI3K or human epidermal growth factor 2 (HER2) in the presence of E2 and the growth factors IGF or EGF, followed by inhibited the activation of IGF-1Rß, EGFR or HER2, and reduced Akt, MAPK and ERα phosphorylation levels, resulting in significant suppression of proliferation of ERα-positive breast cancer cells in vitro and in vivo. More importantly, combined treatment with ERAP and tamoxifen led to a synergistic suppression of signaling that was activated by crosstalk between E2 and growth factors or HER2 amplification. Taken together, our findings suggest that the specific inhibition of BIG3-PHB2 is a novel potential therapeutic approach for the treatment of tamoxifen-resistant breast cancers activated by the crosstalk between E2 and growth factor signaling, especially in premenopausal women.

A genome-wide association study identifies locus at 10q22 associated with clinical outcomes of adjuvant tamoxifen therapy for breast cancer patients in Japanese.

Although many association studies of polymorphisms in candidate genes with the clinical outcomes of breast cancer patients receiving adjuvant tamoxifen therapy have been reported, genetic factors determining individual response to tamoxifen are not fully understood. To identify genetic polymorphisms associated with clinical outcomes of patients with tamoxifen treatment, we conducted a genome-wide association study (GWAS). We studied 462 Japanese patients with hormone receptor-positive, invasive breast cancer receiving adjuvant tamoxifen therapy. Of them, 240 patients were analyzed by genome-wide genotyping using the Illumina Human610-Quad BeadChips, and two independent sets of 105 and 117 cases were used for replication studies. In the GWAS, we detected significant associations with recurrence-free survival at 15 single-nucleotide polymorphisms (SNPs) on nine chromosomal loci (1p31, 1q41, 5q33, 7p11, 10q22, 12q13, 13q22, 18q12 and 19p13) that satisfied a genome-wide significant threshold (log-rank P= 2.87 × 10(-9)-9.41 × 10(-8)). Among them, rs10509373 in C10orf11 gene on 10q22 was significantly associated with recurrence-free survival in the replication study (log-rank P= 2.02 × 10(-4)) and a combined analysis indicated a strong association of this SNP with recurrence-free survival in breast cancer patients treated with tamoxifen (log-rank P= 1.26 × 10(-10)). Hazard ratio per C allele of rs10509373 was 4.51 [95% confidence interval (CI), 2.72-7.51; P= 6.29 × 10(-9)]. In a combined analysis of rs10509373 genotype with previously identified genetic makers, CYP2D6 and ABCC2, the number of risk alleles of these three genes had cumulative effects on recurrence-free survival among 345 patients receiving tamoxifen monotherapy (log-rank P= 2.28 × 10(-12)). In conclusion, we identified a novel locus associated with recurrence-free survival in Japanese breast cancer patients receiving adjuvant tamoxifen therapy.

Influence of body mass index on clinicopathological factors including estrogen receptor, progesterone receptor, and Ki67 expression levels in breast cancers.

BACKGROUND: High body mass index (BMI) is associated not only with a higher incidence of breast cancers but also with poorer prognosis. It is speculated that both enhanced production of estrogens and other factors associated with obesity are involved in these associations, but the biological characteristics associated with high BMI have yet to be thoroughly identified. METHODS: We studied 525 breast cancers, focusing on biological differences between tumors associated with high and low BMI and by immunohistochemically defined intrinsic subtype. Ki67 expression levels were used to differentiate luminal A from luminal B estrogen receptor (ER)+/human epidermal growth factor receptor 2 (HER2)-breast cancers. RESULTS: Premenopausal patients with high BMI showed a significantly higher frequency of lymph node metastasis (46.4 % vs. 22.9 %, P = 0.005) and tended to have a larger tumor size (P = 0.05) and higher nuclear grade (P = 0.07) than those with low BMI. These differences were not observed among postmenopausal patients. BMI was not associated with distribution of breast cancer subtypes, and ER, progesterone receptor (PR), and Ki67 expression levels of each subtype showed no differences between high and low BMI among premenopausal patients. CONCLUSION: Higher BMI might influence aggressive tumor characteristics among premenopausal patients, but its influence on ER, PR, and Ki67 expression levels seems to be limited.

A genome-wide association study of chemotherapy-induced alopecia in breast cancer patients.

INTRODUCTION: Chemotherapy-induced alopecia is one of the most common adverse events caused by conventional cytotoxic chemotherapy, yet there has been very little progress in the prevention or treatment of this side effect. Although this is not a life-threatening event, alopecia is very psychologically difficult for many women to manage. In order to improve the quality of life for these women, it is important to elucidate the molecular mechanisms of chemotherapy-induced alopecia and develop ways to effectively prevent and/or treat it. To identify the genetic risk factors associated with chemotherapy-induced alopecia, we conducted a genome-wide association study (GWAS) using DNA samples from breast cancer patients who were treated with chemotherapy. METHODS: We performed a case-control association study of 303 individuals who developed grade 2 alopecia, and compared them with 880 breast cancer patients who did not show hair loss after being treated with conventional chemotherapy. In addition, we separately analyzed a subset of patients who received specific combination therapies by GWASs and applied the weighted genetic risk scoring (wGRS) system to investigate the cumulative effects of the associated SNPs. RESULTS: We identified an SNP significantly associated with drug-induced grade 2 alopecia (rs3820706 in CACNB4 (calcium channel voltage-dependent subunit beta 4) on 2q23, P = 8.13 × 10(-9), OR = 3.71) and detected several SNPs that showed some suggestive associations by subgroup analyses. We also classified patients into four groups on the basis of wGRS analysis and found that patients who classified in the highest risk group showed 443 times higher risk of antimicrotubule agents-induced alopecia than the lowest risk group. CONCLUSIONS: Our study suggests several associated genes and should shed some light on the molecular mechanism of alopecia in chemotherapy-treated breast cancer patients and hopefully will contribute to development of interventions that will improve the quality of life (QOL) of cancer patients.

Dose-adjustment study of tamoxifen based on CYP2D6 genotypes in Japanese breast cancer patients.

CYP2D6 is a key enzyme responsible for the metabolism of tamoxifen to active metabolites, endoxifen, and 4-hydroxytamoxifen. The breast cancer patients who are heterozygous and homozygous for decreased-function and null alleles of CYP2D6 showed lower plasma concentrations of endoxifen and 4-hydroxytamoxifen compared to patients with homozygous-wild-type allele, resulting in worse clinical outcome in tamoxifen therapy. We recruited 98 Japanese breast cancer patients, who had been taking 20 mg of tamoxifen daily as adjuvant setting. For the patients who have one or no normal allele of CYP2D6, dosages of tamoxifen were increased to 30 and 40 mg/day, respectively. The plasma concentrations of tamoxifen and its metabolites were measured at 8 weeks after dose-adjustment using liquid chromatography-tandem mass spectrometry. Association between tamoxifen dose and the incidence of adverse events during the tamoxifen treatment was investigated. In the patients with CYP2D6*1/*10 and CYP2D6*10/*10, the mean plasma endoxifen levels after dose increase were 1.4- and 1.7-fold higher, respectively, than those before the increase (P < 0.001). These plasma concentrations of endoxifen achieved similar level of those in the CYP2D6*1/*1 patients receiving 20 mg/day of tamoxifen. Plasma 4-hydroxytamoxifen concentrations in the patients with CYP2D6*1/*10 and CYP2D6*10/*10 were also significantly increased to the similar levels of the CYP2D6*1/*1 patients according to the increasing tamoxifen dosages (P < 0.001). The incidence of adverse events was not significantly different between before and after dose adjustment. This study provides the evidence that dose adjustment is useful for the patients carrying CYP2D6*10 allele to maintain the effective endoxifen level.

A genome-wide association study identifies a genetic variant in the SIAH2 locus associated with hormonal receptor-positive breast cancer in Japanese.

In Japan, breast cancer is the most common cancer among women and the second leading cause of cancer death among women worldwide. To identify genetic variants associated with the disease susceptibility, we performed a genome-wide association study (GWAS) using a total of 1086 Japanese female patients with hormonal receptor-positive (HRP) breast cancer and 1816 female controls. We selected 33 single-nucleotide polymorphisms (SNPs) with suggestive associations in GWAS (P-value of <1 × 10(-4)) as well as 4 SNPs that were previously implicated their association with breast cancer for further replication by an independent set of 1653 cases and 2797 controls. We identified significant association of the disease with a SNP rs6788895 (P(combined) of 9.43 × 10(-8) with odds ratio (OR) of 1.22) in the SIAH2 (intron of seven in absentia homolog 2) gene on chromosome 3q25.1 where the involvement in estrogen-dependent diseases was suggested. In addition, rs3750817 in intron 2 of the fibroblast growth factor receptor 2 gene, which was reported to be associated with breast cancer susceptibility, was significantly replicated with P(combined) of 8.47 × 10(-8) with OR=1.22. Our results suggest a novel susceptibility locus on chromosome 3q25.1 for a HRP breast cancer.

False-negatives due to poor specimens can be prevented based on the macroscopic findings for breast Vacuum-Assisted Biopsy specimens.

PURPOSE: Ultrasound-guided breast tissue biopsy is an essential technique for diagnosing breast disease, but sample errors reduce its accuracy. This study investigated whether the histopathological results can be inferred from the macroscopic findings for Ultrasound-guided breast Vacuum Assisted Biopsy (VAB) specimens. METHODS: Biopsy specimens from 101 patients who underwent mammary gland VAB were photographed with a smartphone, and the relationships between the macroscopic findings and the pathological results were examined. RESULTS: A significant difference was observed with regard to the presence/absence of turbidity: malignancy was detected in 33/37 (89%) specimens with turbidity and in 2/47 (4%) cases without turbidity (p<0.001). A significant difference was also observed regarding the surface properties:malignancy was detected in 14/70 (19%) smooth specimens and in 24/29 (83%) rough specimens (p<0.001). Also, malignancy was detected in 11/13 (85%) specimens with white spots, and the difference was significant (p<0.001). In addition, the characteristics of intraductal papilloma, fibroadenoma, and mastopathy could be confirmed by macroscopic findings. CONCLUSIONS: When needle-biopsy of a lesion that is targeted for resection yields macroscopic findings that match the predicted histopathological findings, it can be thought that the biopsy had been properly performed. This means that false-negatives due to poor specimens can be prevented. J. Med. Invest. 69 : 51-56, February, 2022.

Axillary lymphangioma that developed following COVID-19 vaccination: a case report.

BACKGROUND: Extensive vaccination programs are being implemented worldwide for coronavirus disease 2019 (COVID-19). With the spread of vaccination, swelling of the lymph nodes after vaccination is frequently seen. We encountered a patient who developed left axillary lymphadenoma following vaccine administration. CASE PRESENTATION: The patient was a Japanese woman in her 80 s who had previously undergone surgery for right breast cancer. She received two injections of the Pfizer-BioNTech COVID-19 vaccine in her left arm. Approximately 3 months later, she complained of left axillary swelling, and imaging resulted in a diagnosis of left axillary lymphangioma. In accordance with the patient's wishes, we performed axillary mass resection. The pathological diagnosis was lymphangioma. CONCLUSION: Our examination findings indicated that congestion of the axillary lymph vessels might have been caused by upper-arm injections of the COVID-19 vaccine.

Genome-wide association study of epirubicin-induced leukopenia in Japanese patients.

OBJECTIVES: Despite long-term clinical experience with epirubicin, unpredictable severe adverse reactions remain an important determinant to limit the drug use. To identify a genetic factor(s) affecting the risk of epirubicin-induced leukopenia/neutropenia, we performed a genome-wide association study. METHODS: We studied 270 patients consisting of 67 patients with grade 3 or 4 leukopenia/neutropenia, and 203 patients showing no toxicity (patients with grade 1 or 2 were excluded from the study) for genome-wide association study. We further examined the single nucleotide polymorphisms (SNPs) showing P values of less than 0.0001 using an additional set of 48 patients with grade 3/4 leukopenia/neutropenia. RESULTS: The combined analysis indicated that rs2916733 in microcephalin 1 [combined PFisher min=2.27×10, odds ratio (OR)=2.74 with 95% confidence interval (CI)=1.96-3.83; the nonrisk genotype as reference] was significantly associated with epirubicin-induced leukopenia/neutropenia. A subgroup analysis of patients with only breast cancer showed a similar trend of association for the marker SNP rs2916733 (combined PFisher min=6.76×10, OR=2.80 with 95% CI=1.86-4.21). We subsequently performed haplotype analysis and found that a haplotype constructed from rs2916733 and rs1031309, which was in linkage disequilibrium with rs2916733 (r=0.64), showed stronger association (P=2.20×10, OR=2.88 with 95% CI=2.05-4.03) than a single landmark SNP (rs2916733; P=2.27×10, OR=2.74 with 95% CI=1.96-3.83), suggesting that causative variant(s) that could influence the susceptibility of epirubicin-induced adverse drug reactions (ADRs) might exist in this haplotype. CONCLUSION: Our findings show that genetic variants in the microcephalin 1 locus are suggestively associated with the risk of epirubicin-induced ADRs and might be applicable in development of diagnostic system for predicting the risk of the ADRs, leading to better prognosis and quality of life for patients with cancer. However, these results should be considered preliminary until replicated in adequately larger powered and controlled samples.

The time since last menstrual period is important as a clinical predictor for non-steroidal aromatase inhibitor-related arthralgia.

BACKGROUND: The clinical predictors of aromatase inhibitor-related arthralgia (AIA), a drug-related adverse reaction of aromatase inhibitors (AIs), remain unclear. METHODS: AIA was prospectively surveyed every 4 months in 328 postmenopausal breast cancer patients administered a non-steroidal AI (anastrozole). Various clinicopathological parameters were recorded and analyzed (chi-square test, Fisher's exact test and logistic regression analysis). RESULTS: The mean observation period was 39.9 months. AIA manifested in 114 patients (34.8%), with peaks of onset at 4 (33.7%) and 8 months (11.4%) after starting AI administration. Some cases manifested even after 13 months. AIA tended to occur in younger patients (incidences of 46.3%, 37.4% and 28.0% for ages of < 55, 55-65 and > 65 years, respectively (p = 0.063)) and decreased significantly with the age at menarche (53.3%, 35.3% and 15.4% for < 12, 12-15 and > 15 years, respectively (p = 0.036)). The incidences were 45.1%, 46.3 and 25.1% for the time since the last menstrual period (LMP) < 5 years, 5-10 years and > 10 years, being significantly lower at > 10 years (p < 0.001). In logistic regression analysis, the AIA incidence was significantly lower in the time since LMP > 10-year group versus the < 5-year group (odds ratio 0.44, p = 0.002), but the age at menarche showed no association. AIA manifested significantly earlier (≤ 6 months) as the time since LMP became shorter (< 5 years). CONCLUSION: AIA tends to manifest early after starting AI, but some cases show delayed onset. The incidence was significantly lower in patients with a duration of > 10 years since LMP. When the time since LMP was short, the onset of AIA was significantly earlier after starting AI administration.

Lessons for pharmacogenomics studies: association study between CYP2D6 genotype and tamoxifen response.

We earlier reported a significant association between the cytochrome P450 2D6 (CYP2D6) genotype and the clinical outcome in 282 Japanese breast cancer patients receiving tamoxifen monotherapy. Although many research groups have provided evidence indicating the CYP2D6 genotype as one of the strongest predictors of tamoxifen response, the results still remain controversial. We hypothesized that concomitant treatment was one of the causes of these controversial results. We then studied 167 breast cancer patients who received tamoxifen-combined therapy to evaluate the effects of concomitant treatment on the association analysis and observed no significant association between CYP2D6 genotype and recurrence-free survival (P=0.44, hazard ratio: 0.64, 95% confidential interval: 0.20-1.99 in patients with two variant alleles vs. patients without a variant allele). When we carried out two subgroup analyses for nodal status and tumor size, we observed a positive association between the CYP2D6 genotype and the clinical outcome only in patients who received tamoxifen monotherapy. This study explained a part of the discrepancies among the reported results.

The GALNT6­LGALS3BP axis promotes breast cancer cell growth.

Polypeptide N­acetylgalactosaminyltransferase 6 (GALNT6), which is involved in the initiation of O­glycosylation, has been reported to play crucial roles in mammary carcinogenesis through binding to several substrates; however, its biological roles in mediating growth­promoting effects remain unknown. The present study demonstrated a crucial pathophysiological role of GALNT6 through its O­glycosylation of lectin galactoside­binding soluble 3 binding protein (LGALS3BP), a secreted growth­promoting glycoprotein, in breast cancer growth. The Cancer Genome Atlas data analysis revealed that high expression levels of GALNT6 were significantly associated with poor prognosis of breast cancer. GALNT6 O­glycosylated LGALS3BP in breast cancer cells, whereas knockdown of GALNT6 by siRNA led to the inhibition of both the O­glycosylation and secretion of LGALS3BP, resulting in the suppression of breast cancer cell growth. Notably, LGALS3BP is potentially O­glycosylated at three sites (T556, T571 and S582) by GALNT6, thereby promoting autocrine cell growth, whereas the expression of LGALS3BP with three Ala substitutions (T556A, T571A and S582A) in cells drastically reduced GALNT6­dependent LGALS3BP O­glycosylation and secretion, resulting in suppression of autocrine growth­promoting effect. The findings of the present study suggest that the GALNT6­LGALS3BP axis is crucial for breast cancer cell proliferation and may be a therapeutic target and biomarker for mammary tumors.

Serum estradiol should be monitored not only during the peri-menopausal period but also the post-menopausal period at the time of aromatase inhibitor administration.

BACKGROUND: Aromatase inhibitor (AI) therapy is being extensively used as postoperative adjuvant therapy in patients with hormone receptor-positive postmenopausal breast cancer. On the other hand, it has been reported that ovarian function was restored when AI was administered to patients who had undergone chemical menopause with chemotherapy or tamoxifen. However, there have been no reports of comprehensive monitoring of estradiol (E2) in breast cancer patients with ordinary menopause who were being administered AI. PATIENTS AND METHODS: Beginning in March 2008, regular monitoring of the serum levels of E2, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) was performed for 66 postmenopausal breast cancer patients who had been started on AI therapy. For this study, we chose anastrozole as the AI. The assays of those hormones were outsourced to a commercial clinical laboratory. RESULTS: In 4 of the 66 patients the serum E2 level was decreased at 3 months but had then increased at 6 months, while in 2 other patients E2 was decreased at both 3 and 6 months but had increased at 9 months. CONCLUSION: The results indicate that, in some breast cancer patients with ordinary menopause, E2 rebounds following AI therapy. In the future, E2 monitoring should be performed for a larger number of patients being administered AI therapy. TRIAL REGISTRATION: Our trial registration number is 19-11-1211.

Impact of CYP2D6*10 on recurrence-free survival in breast cancer patients receiving adjuvant tamoxifen therapy.

The clinical outcomes of breast cancer patients treated with tamoxifen may be influenced by the activity of cytochrome P450 2D6 (CYP2D6) enzyme because tamixifen is metabolized by CYP2D6 to its active forms of antiestrogenic metabolite, 4-hydroxytamoxifen and endoxifen. We investigated the predictive value of the CYP2D6*10 allele, which decreased CYP2D6 activity, for clinical outcomes of patients that received adjuvant tamoxifen monotherapy after surgical operation on breast cancer. Among 67 patients examined, those homozygous for the CYP2D6*10 alleles revealed a significantly higher incidence of recurrence within 10 years after the operation (P = 0.0057; odds ratio, 16.63; 95% confidence interval, 1.75-158.12), compared with those homozygous for the wild-type CYP2D6*1 alleles. The elevated risk of recurrence seemed to be dependent on the number of CYP2D6*10 alleles (P = 0.0031 for trend). Cox proportional hazard analysis demonstrated that the CYP2D6 genotype and tumor size were independent factors affecting recurrence-free survival. Patients with the CYP2D6*10/*10 genotype showed a significantly shorter recurrence-free survival period (P = 0.036; adjusted hazard ratio, 10.04; 95% confidence interval, 1.17-86.27) compared to patients with CYP2D6*1/*1 after adjustment of other prognosis factors. The present study suggests that the CYP2D6 genotype should be considered when selecting adjuvant hormonal therapy for breast cancer patients.

Thymidine phosphorylase and dihydropyrimidine dehydrogenase are predictive factors of therapeutic efficacy of capecitabine monotherapy for breast cancer-preliminary results.

Capecitabine monotherapy was administered for 25 patients with advanced or recurrent breast cancer, and the clinical therapeutic efficacy and its relationship to expression of 5-fluorouracil-related enzymes (i. e., thymidine phosphorylase (TP), thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD)) were investigated. The expressions of TP, TS and DPD were determined by immunohistochemical staining techniques and rated using a scoring system of 1~4. The expression score for TP/DPD showed a statistically significant correlation with the clinical response, whereas the expression score for TP/TS also showed a correlation but it was not statistically significant. The number of patients was small, but the results revealed the potential of application of the TP/DPD expression score as a factor for predicting the efficacy of the drug in individual patients.

Clinical efficacy and problems with CT lymphography in identifying the sentinel node in breast cancer.

BACKGROUND: Combining a radioisotope with a dye-guided method is the best method for identification of the sentinel lymph nodes (SNs) in breast cancer. However, some institutions are limited to use of a dye-guided method alone. Recently, computed tomographic lymphography (CTLG) employing a nonionic contrast medium has achieved SN identification. PATIENTS AND METHODS: 218 patients with primary breast cancer and no clinical evidence of lymph node metastasis were studied. SN identification was performed by CTLG and a dye-guided method. The SN identification rate was analyzed for correlations with the clinicopathological findings. RESULTS: The SN identification rates were 96% with CTLG, 92% with the dye-guided method and 99% with both methods combined. The identification rates with CTLG and the combined method were significantly lower in node-positive patients compared to node-negative patients, and significantly lower with the combined method in vascular invasion-positive patients compared to negative patients. In addition, the SN identification rate with the dye-guided method was significantly lower in patients with a body mass index (BMI) of > or = 25, whereas the BMI did not affect the identification rate with CTLG or the combined method. Multiple SNs were detected in approximately 20% of the patients. CONCLUSION: Combined performance of CTLG and a dye-guided method enables identification of SNs prior to breast cancer surgery. That SN identification is easier compared with by the dye-guided method alone, and the identification rate is improved compared with either method alone. The combination of methods was especially useful in obese patients. For patients with multiple SNs, the combination has the further advantage of enabling accurate SN biopsy. CTLG may yield false-negative findings in node-positive patients and patients with lymph vessel obstruction.

A case of matrix-producing carcinoma of the breast.

BACKGROUND: Matrix-producing carcinoma (MPC) of the breast is one variant type of metaplastic carcinoma. The cellular origin of MPC remains unclear. It has been suggested the tumor cells in MPC have the combined characteristics of both epithelial cells and mesenchymal cells. Several reports suggested that the tumor cells in MPC might originate from the myoepithelial cells, but others suggested the origin was basal-like cells. CASE PRESENTATION: The patient was a 42-year-old Japanese female. A tumor of about 2 cm in diameter was noted in the right breast. CT revealed the circumference of the tumor to have a ring-like structure, and fine needle aspiration cytology indicated suspicion for malignancy. Breast-conserving surgery was performed. Histopathological studies showed carcinoma cells, having cuboidal to oval-shaped nucleus, were proliferating in cord-like and sheet-like structures in the periphery. In the central areas of the tumor, myxoedematous area was observed with cartilaginous matrix and necrosis. The diagnosis was a matrix-producing carcinoma. Immunohistochemical findings showed the tumor cells had the characteristics of both epithelial cells and mesenchymal cells, while being negative for estrogen receptor, progesterone receptor, Her2, myoepithelial cell markers and basal cell markers. CONCLUSION: The findings for our present patient and many of the other MPC patients reported in the published literature indicate that this breast cancer has the properties of both epithelial cells and mesenchymal cells. In addition, there is a possibility that matrix-producing tumor cells of our present patient may have a feature of undifferentiated cells.

Frequent downregulation of LRRC26 by epigenetic alterations is involved in the malignant progression of triple-negative breast cancer.

Triple-negative breast cancer (TNBC), defined as breast cancer lacking estrogen- and progesterone­receptor expression and human epidermal growth factor receptor 2 (HER2) amplification, is a heterogeneous disease. RNA-sequencing analysis of 15 TNBC specimens and The Cancer Genome Atlas-TNBC dataset analysis identified the frequent downregulation of leucine-rich repeat-containing 26 (LRRC26), which negatively regulates nuclear factor-κB (NF-κB) signaling, in TNBC tissues. Quantitative polymerase chain reaction and bisulfite pyrosequencing analyses revealed that LRRC26 was frequently silenced in TNBC tissues and cell lines as a result of promoter methylation. LRRC26 expression was restored by 5-aza-2'-deoxycytidine (5'-aza-dC) treatment in HCC1937 TNBC cells, which lack LRRC26 expression. Notably, small interfering RNA-mediated knockdown of LRRC26 expression significantly enhanced the anchorage-independent growth, invasion and migration of HCC70 cells, whereas ectopic overexpression of LRRC26 in BT20 cells suppressed their invasion and migration. Conversely, neither knockdown nor overexpression of LRRC26 had an effect on cell viability in the absence of tumor necrosis factor-α (TNF-α) stimulation. Meanwhile, overexpression of LRRC26 caused the reduction of TNF-α-mediated NF-κB luciferase reporter activity, whereas depleting LRRC26 expression resulted in the upregulation of TNF-α-mediated NF-κB downstream genes [interleukin-6 (IL-6), IL-8 and C-X-C motif chemokine ligand-1]. Taken together, these findings demonstrate that LRRC26 is frequently downregulated in TNBC due to DNA methylation and that it suppresses the TNF-α-independent anchorage-independent growth, invasion and migration of TNBC cells. Loss of LRRC26 function may be a critical event in the aggressiveness of TNBC cells through a TNF-α/NF-κB-independent mechanism.

Chromosomal aneusomy (chr 1, 11, 17) detected by fluorescence in situ hybridization may be a prognostic factor in breast cancer.

The relationship between clinicopathological findings and the long-term prognosis was investigated in 42 breast cancer patients in whom aneusomy was detected for chromosomes 1, 11 and 17. The frequencies of aneusomy of those chromosomes were 78.6%, 47.5% and 52.5%, respectively, and more than 90% of anomalies consisted of polysomy. The relationship between aneusomy and the clinicopathological findings showed a statistical correlation with a high histological grade in the case of polysomy of chromosome 17 compared with disomy, indicating a tendency for a high incidence of lymph node metastasis. Analysis of the survival data revealed that the prognosis was poor when there was polysomy of chromosomes 1 or 11. These results indicate the possibility that aneusomy of chromosomes 1, 11 and 17 can serve as prognostic factors of poor outcome in breast cancer patients.

Bilateral male breast cancer with male potential hypogonadism.

BACKGROUND: Male breast cancer is a comparatively rare disease, and simultaneous bilateral male breast cancer is considered to be an extremely rare event. Risk factors are said to be genetic factors and hormonal abnormalities due to obesity or testicular diseases. CASE PRESENTATION: The patient was a 47-year-old Japanese male. His family had no history of female breast cancer. This patient also had hypospadias and hormonal examination indicated the presence of primary testicular potential hypogonadism, and these hormonal abnormalities seemed to be present since childhood or the fetal period. The bilateral breast cancer developed in this man at a comparatively young age, and histopathological studies of multiple sections showed that there was almost no normal epithelial cell in the ducts, while the ducts were almost completely filled with breast cancer cells. CONCLUSION: It is thought that male breast cancer is caused by an imbalance between estrogen and testosterone. We cannot rule out the possibility that the breast cancer developed due to the effect of the slight elevation of estrogen over a long period of time, but the actual causative factors in this patient were unable to be definitively identified. In the future, we hope to further elucidate the causes of male breast cancer.