Kazuma Maeno

Increased nuclear localization of transcription factor Y-box binding protein 1 accompanied by up-regulation of P-glycoprotein in breast cancer pretreated with paclitaxel.

Purpose: The Y-box binding protein 1 (YB-1) regulates expression of P-glycoprotein encoded by the MDR1 gene. There have been no previous studies regarding the involvement of YB-1 in the development of resistance to paclitaxel. The present study was done to examine how paclitaxel affects the localization and expression of YB-1 in breast cancer. Experimental Design: We evaluated the expression and localization of YB-1 and P-glycoprotein in breast cancer tissues obtained from 27 patients before and after treatment with paclitaxel. The effect of paclitaxel on localization of cellular YB-1 was examined by using GFP-YB-1. Interaction of YB-1 with the Y-box motif of the MDR1 promoters was studied by electrophoretic mobility shift assay. The effects of paclitaxel on MDR1 promoter activity were examined by luciferase assay. Results: Of 27 breast cancer tissues treated with paclitaxel, nine (33%) showed translocation of YB-1 from the cytoplasm to the nucleus together with increased expression of P-glycoprotein during the course of treatment. Twelve breast cancer tissues (44%) showed neither translocation of YB-1 nor increased expression of P-glycoprotein. Nuclear translocation of YB-1 was correlated significantly with increased expression of P-glycoprotein (P = 0.0037). Confocal analysis indicated that paclitaxel induced nuclear translocation of green fluorescent fused YB-1 in MCF7 cells. Furthermore, binding of YB-1 to the Y-box of MDR1 promoter was increased in response to treatment with paclitaxel. In addition, MDR1 promoter activity was significantly up-regulated by paclitaxel in MCF7 cells (P < 0.001). Conclusions: The results of the present study suggested that YB-1 may be involved in the development of resistance to paclitaxel in breast cancer.

Multimodality therapeutic outcomes In anaplastic thyroid carcinoma: Improved survival in subgroups of patients with localized primary tumors

The aim of the present study was to investigate the role of a multimodality treatment for anaplastic thyroid carcinoma (ATC).

Mutation of the class I β-tubulin gene does not predict response to paclitaxel for breast cancer

Mutation of the class I beta-tubulin gene has been reported to be one of the mechanisms that cause resistance to paclitaxel. To assess the relationship between paclitaxel-resistance and class I beta-tubulin gene mutation in breast cancer, Japanese patients with breast cancer were screened for the class I beta-tubulin gene mutation. Total RNA was isolated from 82 breast cancer specimens and the corresponding normal tissues. Twenty-four of the 82 patients were treated with paclitaxel preoperatively and 12 of them did not respond to the treatment. Of the 82 breast cancer patients, 15 (18.3%) had silent polymorphism in exon 4, Leu217Leu (CTG/CTA). However, no mutations showing amino acid substitution of the beta-tubulin gene were detected in any of the patients, including 12 patients who did not respond to paclitaxel. Class I beta-tubulin gene mutation with amino acid substitution was not detected in 82 breast cancer specimens. Our results suggest that mutation of the class I beta-tubulin gene is unlikely to play an important role in the mechanism of resistance to paclitaxel in breast cancer.

Molecular Basis for Reduced Estrone Sulfate Transport and Altered Modulator Sensitivity of Transmembrane Helix (TM) 6 and TM17 Mutants of Multidrug Resistance Protein 1 (ABCC1)

Multidrug resistance protein 1 (MRP1) confers drug resistance and also mediates cellular efflux of many organic anions. MRP1 also transports glutathione (GSH); furthermore, this tripeptide stimulates transport of several substrates, including estrone 3-sulfate. We have previously shown that mutations of Lys332 in transmembrane helix (TM) 6 and Trp1246 in TM17 cause different substrate-selective losses in MRP1 transport activity. Here we have extended our characterization of mutants K332L and W1246C to further define the different roles these two residues play in determining the substrate and inhibitor specificity of MRP1. Thus, we have shown that TM17-Trp1246 is crucial for conferring drug resistance and for binding and transport of methotrexate, estradiol glucuronide, and estrone 3-sulfate, as well as for binding of the tricyclic isoxazole inhibitor N-[3-(9-chloro-3-methyl-4-oxo-4H-isoxazolo-[4,3-c]quinolin-5-yl)-cyclohexylmethyl]-benzamide (LY465803). In contrast, TM6-Lys332 is important for enabling GSH and GSH-containing compounds to serve as substrates (e.g., leukotriene C4) or modulators (e.g., S-decyl-GSH, GSH disulfide) of MRP1 and, further, for enabling GSH (or S-methyl-GSH) to enhance the transport of estrone 3-sulfate and increase the inhibitory potency of LY465803. On the other hand, both mutants are as sensitive as wild-type MRP1 to the non–GSH-containing inhibitors (E)-3-[[[3-[2-(7-chloro-2-quinolinyl)ethenyl]phenyl][[3-(dimethylamino)-3-oxopropyl]thio]methyl]thio]-propanoic acid (MK571), 1-[2-hydroxy-3-propyl-4-[4-(1H-tetrazol-5-yl)butoxy]phenyl]-ethanone (LY171883), and highly potent 6-[4′-carboxyphenylthio]-5[S]-hydroxy-7[E], 11[Z]14[Z]-eicosatetrenoic acid (BAY u9773). Finally, the differing abilities of the cysteinyl leukotriene derivatives leukotriene C4, D4, and F4 to inhibit estradiol glucuronide transport by wild-type and K332L mutant MRP1 provide further evidence that TM6-Lys332 is involved in the recognition of the γ-Glu portion of substrates and modulators containing GSH or GSH-like moieties.

CSLEX (Sialyl Lewis X) is a Useful Tumor Marker for Monitoring of Breast Cancer Patients

BACKGROUND CSLEX is a type II carbohydrate antigen that interacts with the CSLEX-1 monoclonal antibody. CSLEX in combination with carbohydrate antigen 15-3 may be more useful than Carcinoembryonic Antigen with carbohydrate antigen 15-3 as tumor markers for monitoring of breast cancer. METHODS The serum levels of tumor markers, including CSLEX, were measured in 480 consecutive breast cancer patients with or without metastasis who visited the outpatient clinic of the Division of Breast and Endocrine Surgery, Shinshu University Hospital, between April 2007 and September 2007. RESULTS Serum levels of each of the tumor markers correlated significantly with the status of metastasis (P < 0.01). Combinations of Carcinoembryonic Antigen and carbohydrate antigen 15-3, Carcinoembryonic Antigen and Nation Cancer Center-Stomach-439, Carcinoembryonic Antigen and CSLEX, carbohydrate antigen 15-3 and Nation Cancer Center-Stomach-439, and carbohydrate antigen 15-3 and CSLEX levels also correlated significantly with the status of metastasis (P < 0.01). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were almost the same for CSLEX and Nation Cancer Center-Stomach-439, which are both type II carbohydrate antigens. The cutoff indexes of serum CSLEX and Nation Cancer Center-Stomach-439 for detection of breast cancer metastasis were 38.8 ± 52.7-fold and 22.1 ± 27.8-fold, respectively (P = 0.16). CONCLUSIONS These data suggest that the diagnostic values of CSLEX and Nation Cancer Center-Stomach-439 are similar in single or combined use. However, the cutoff index of serum CSLEX tended to be higher than that of Nation Cancer Center-Stomach-439, which may make CSLEX more useful for detection of breast cancer metastasis.

Breast metastases of gastric signet-ring cell carcinoma: a report of two cases and review of the literature.

It is occasionally difficult to diagnose breast metastasis of gastric carcinoma because of its rarity. However, to appropriately treat patients with breast tumors without delay, it is important to distinguish metastatic cancer from primary breast cancer. We report two cases of breast metastasis of gastric carcinoma and review the literature. The first case was a 41-year-old female diagnosed with bilateral pelvic tumors who visited the outpatient clinic because of pain and enlargement of both breasts. Ultrasonography showed diffuse hypoechoic lesions, which were enhanced on gadolinium-enhanced magnetic resonance imaging in the bilateral mammary gland. Core needle biopsy of the right breast revealed signet-ring cells, which were also identified in the resected bilateral pelvic tumors. Subsequent upper gastrointestinal endoscopy revealed signet-ring cell carcinoma in the stomach, and the bilateral breast lesions were diagnosed as metastases of gastric carcinoma. The second case was a 34-year-old female diagnosed with cervical metastasis of signet-ring cell carcinoma who was referred to the breast cancer clinic because of a nodule in the left breast detected by computed tomography. Ultrasonography showed a hypoechoic nodule that was enhanced on gadolinium-enhanced magnetic resonance imaging. Because the pathologic findings for the left breast nodule were quite similar to those of gastric cancer and its cervical metastasis, the breast nodule was diagnosed as a metastasis of gastric carcinoma. When a breast tumor is suspected to have metastasized from a primary tumor in another organ, particularly if signet-ring cells are found, the possibility that gastric cancer is present should be considered.

Lipid-rich carcinoma of the breast that is strongly positive for estrogen receptor: a case report and literature review.

Lipid-rich carcinoma (LRC) of the breast is a rare breast cancer variant that accounts for <1% of all breast malignancies. It has been reported that LRCs are negative for estrogen receptor. Here, we report a case of LRC of the breast that was strongly positive for estrogen receptor and treated with endocrine adjuvant therapy. A 52-year-old postmenopausal female noticed a lump in her right breast by self-examination and presented to our hospital. Physical examination revealed an elastic 30 mm ×20 mm hard mass in the upper medial part of her right breast. The findings obtained using ultrasonography, mammography, and contrast-enhanced magnetic resonance imaging suggested breast cancer. Core needle biopsy resulted in the diagnosis of invasive carcinoma. The patient underwent mastectomy and sentinel lymph node biopsy. Histopathologically, the tumor cells were abundant in foamy cytoplasm. Because the presence of marked cytoplasmic lipid droplets was confirmed by Sudan IV staining and electron microscopic examination of the tumor and the lipid droplets were negative for periodic acid–Schiff staining, the tumor was diagnosed as an LRC. Immunohistochemically, estrogen and progesterone receptors of the tumor were strongly positive, human epidermal growth factor receptor type 2 was negative, and the ratio of Ki-67-positive cells was ~30%. After surgery, the patient underwent combination chemotherapy with anthracycline, cyclophosphamide, and 5-fluorouracil, followed by docetaxel. Thereafter, the pateint was treated with letrozole and has remained well for 24 months with no signs of recurrence.

Human 3β-hydroxysteroid dehydrogenase type 1 in human breast cancer: clinical significance and prognostic associations.

Active sex steroids including estrogens and androgens are locally produced from circulating inactive steroids by various steroid‐metabolizing enzymes, and play pivotal roles in the progression of hormone‐dependent breast cancers. Human 3β‐hydroxysteroid dehydrogenase type 1 (3β‐HSD type 1) is a critical enzyme in the formation of all classes of active steroid hormones, and is also involved in the inactivation of potent androgen dihydrotestosterone (DHT). Therefore, this enzyme is suggested to modulate active sex steroid production or inactivation, with a role in hormone‐dependent breast cancer. The purpose of this study was to investigate the clinical significance of 3β‐HSD type 1 in human breast cancer. Using immunohistochemistry (IHC), we evaluated 3β‐HSD type 1 expression in 161 human breast cancers and analyzed correlations of 3β‐HSD type 1 expression with various clinicopathological factors. Of 161 breast cancer cases, 3β‐HSD type 1 expression in cancer cells was detected in 119 cases (73.9%), and was positively correlated with estrogen receptor (ER)‐positivity but not HER‐2 status. In ER‐positive cases (n = 130), 3β‐HSD type 1 expression was inversely correlated with invasive tumor size (P = 0.0009), presence of invasive region (P = 0.0107), and lymphatic involvement (P = 0.0004). 3β‐HSD type 1 expression was significantly associated with decreased risk of recurrence or improved prognosis by both univariate (P = 0.0003 and P = 0.009, respectively) and multivariate (P = 0.027 and P = 0.023, respectively) analyses. Our findings indicate that this enzyme is a prognostic factor in hormone‐dependent breast cancer.

5-Hydroxymethylcytosine as a putative marker for erosive adenomatosis of the nipple.

Dear Editor, Erosive adenomatosis of the nipple (EAN) represents a benign mammary proliferation of lactiferous ducts. It often presents with erosion, nodularity and erythema. EAN occasionally mimics well-differentiated adenocarcinoma. 5-Hydroxymethylcytosine (5-hmC) is an epigenetic modifier that plays essential roles in diseases as well as in development. Levels of 5-hmC are low in human cancers. Here, we report two cases of EAN, which revealed a high level of 5-hmC expression, different from an adenocarcinoma lesion.

Full-thickness chest-wall resection followed by thorax reconstruction for recurrent malignant phyllodes tumor

We present a case of a 39-year-old woman with a giant recurrent malignant phyllodes tumor accompanied with bleeding and infection. She underwent full-thickness chest-wall resection. Bony thorax reconstruction and stabilization was accomplished using a Composix mesh™, and soft tissue reconstruction was performed with a musculocutaneous flap of latissimus dorsi muscle. The patient had a good postoperative outcome, and the surgical treatment remarkably improved her quality of life. Because chemotherapy and radiation are not established for treating malignant phyllodes tumors, an aggressive surgical approach should be considered for patients with a locally advanced malignant phyllodes tumor.