Neoadjuvant chemotherapy using nanoparticle albumin-bound paclitaxel plus trastuzumab and pertuzumab followed by epirubicin and cyclophosphamide for operable HER2-positive primary breast cancer: a multicenter phase II clinical trial (PerSeUS-BC04).

BACKGROUND: Nanoparticle albumin-bound paclitaxel (nab-PTX) is a promising antibody partner for anti-human epidermal growth factor receptor 2 (HER2). We performed neoadjuvant chemotherapy (NAC) for HER2-positive breast cancer (BC) using nab-PTX plus trastuzumab (T-mab) and pertuzumab (P-mab), followed by epirubicin and cyclophosphamide (EC). METHODS: In this multicenter phase II clinical trial (January 2019-July 2020), patients with stage I (T1c)-IIIB HER2-positive primary BC were treated with four cycles of nab-PTX plus T-mab and P-mab, followed by four cycles of EC. The primary endpoint was the pathological complete response (pCR) rate. Secondary endpoints were clinical response rate (RR), adverse events (AE), and tumor-infiltrating lymphocytes (TILs) in biopsy samples. RESULTS: In total, 43 patients were enrolled (mean age, 54 years). Twenty-two patients had HER2, and 21 patients had luminal/HER2-subtypes. The overall pCR rate was 53.5% (23/43, 95% CI: 42.6-64.1%, p = 0.184), whilst the pCR for HER2 was 68.2% (15/22, 95% CI: 45.1-86.1) and 38.1% for luminal/HER2 (8/21, 95% CI: 18.1-61.6%). The RR was 100% [clinical (c) CR:25, partial response (PR): 18]. AEs (≥ G3) included neutropenia (23.3%), leukopenia (7.0%), liver dysfunction (7.0%), and peripheral neuropathy (4.7%) when nab-PTX was administered. EC administration resulted in leukopenia (34.2%), neutropenia (31.6%), and febrile neutropenia (15.8%). The TILs in preoperative biopsy samples were significantly higher in pCR compared to non-pCR samples. CONCLUSION: Nab-PTX plus T-mab and P-mab induced a high pCR rate in HER2-positive BC, particularly in the HER2-subtype. Given that AEs are acceptable, this regimen is safe and acceptable as NAC for HER2-positive BC.

Diagnostic potential of serum extracellular vesicles expressing prostate-specific membrane antigen in urologic malignancies.

We aimed to develop a sandwich ELISA to detect prostate-specific membrane antigen (PSMA) on small extracellular vesicles (EVs) using T-cell immunoglobulin domain and mucin domain-containing protein 4 (Tim4) as a capture molecule for EVs and to evaluate its diagnostic potential in urologic malignancies. First, we optimized the conditions for sandwich ELISA measuring the PSMA level on EVs captured from serum by Tim4 and found that the use of highly-purified EVs released from Tim4 that had captured EVs in serum reduced the background. Second, we confirmed its validity by studying mouse xenograft model for prostate cancer (PC). Lastly, we measured PSMA-EVs in serum of patients with urologic malignancies. The PSMA-EV levels were significantly higher in metastatic PC and castration-resistant PC (CRPC) patients than in therapy-naïve PC patients. In renal cell carcinoma (RCC) patients, PSMA-EVs were elevated in those with metastasis compared with those without metastasis, which may reflect the development of the neovasculature positive for PSMA in tumors. In conclusion, we developed a sandwich ELISA for detection of PSMA-EVs using highly-purified EVs isolated from serum by Tim4. Our results suggest that PSMA-EVs may be useful to diagnose and monitor not only PC but also RCC and possibly other hypervascular solid tumors.

Three-dimensional reconstruction of the axon extending from the dermal photoreceptor cell in the extraocular photoreception system of a marine gastropod, onchidium.

The marine gastropod Onchidium has a multiple photoreceptive system consisting of stalk eyes, dorsal eyes, photosensitive neurons, and extraocular dermal photoreceptor cells (DPCs). The DPCs were widespread all over the dorsal mantle and distributed singly or in groups in the dermis, but were not discernible by the naked eye. The DPC was oval in shape and large in size, and characterized by features specific to gastropod photoreceptor cells such as massive microvilli, photic vesicles, and a depolarized response. DPC-17, one of a group of 19 DPCs, was examined on serial semi-thin sections of 0.4 µm in thickness with a high-voltage transmission electron microscope (HVTEM). The axon emerged specifically from the lateral side between the distal microvillous portion and proximal cytoplasm, travelled through the connective tissue, and joined a small nerve bundle (NB). Two types of supportive cells were found along the length of the axon. The first type was a covering cell (CC) surrounding the surface of the DPC body and continuing onward to the axon sheath. DPC-17 was covered by 11 CCs, while the larger DPC-6 was only covered by four CCs. The second type was a sheath cell (ShC) wrapping the surface of the small NB where the axon of the DPC merged with undefined nerve fibers. The axon extending directly from DPC-17 was reconstructed three-dimensionally (3D) using DeltaViewer software. The 3D-reconstructed image of the sheath of the axon and the CC demonstrated the continuity between the two structures, especially when the image was rotated using DeltaViewer.

Regulation by heat shock protein 27 of osteocalcin synthesis in osteoblasts.

We have previously reported that various stimuli, including sphingosine 1-phosphate, are able to induce heat shock protein (HSP) 27 in osteoblast-like MC3T3-E1 cells. However, the precise role of HSP27 in bone metabolism has not been satisfactory clarified. In this study, we investigated the effect of HSP27 on osteocalcin synthesis induced by bone morphogenetic protein (BMP)-4 or T3 in these cells. In MC3T3-E1 cells, pretreatment with sphingosine 1-phosphate, sodium arsenite, or heat stress caused the attenuation of osteocalcin synthesis induced by BMP-4 or T3 with concurrent HSP27 induction. To further investigate the effect of HSP27, we established stable HSP27-transfected cells. The osteocalcin synthesis was significantly reduced in the stable HSP27-transfected MC3T3-E1 cells and normal human osteoblasts compared with empty-vector transfected cells. On the other hand, anisomycin, a p38 MAPK activator, caused the phosphorylation of HSP27 in both sphingosine 1-phosphate-stimulated untransfected MC3T3-E1 cells and HSP27-transfected MC3T3-E1 cells. An immunofluorescence microscopy study showed that the phosphorylated HSP27 induced by anisomycin concentrated perinuclearly in these cells, in which it colocalized with the endoplasmic reticulum. We also established stable mutant-HSP27-transfected cells. Osteocalcin synthesis induced by either BMP-4 or T3 was markedly suppressed in the nonphosphorylatable HSP27-overexpressing MC3T3-E1 cells compared with the phosphomimic HSP27-overexpressing cells. In contrast, the matrix mineralization was more obvious in nonphosphorylatable HSP27-overexpressing cells than that in phosphomimic HSP27-overexpressing cells. Taken together, these results strongly suggest that unphosphorylated HSP27 has an inhibitory effect on osteocalcin synthesis, but has a stimulatory effect on mineralization, in osteoblasts.

[Clinical significance and problems in HCV measurement--comparison of CLEIA method with PCR method].

Infection of a hepatitis C virus (HCV) is confirmed by the presence of HCV antibody or HCV-RNA. Recently, a highly sensitive method to examine HCV-core antigen has been developed. In this study, to evaluate the clinical significance of HCV-core antigen determination, we examined serum HCV infection markers, HCV-core antigen, HCV-RNA (AMPLICOR) and HCV-antibody (third generation) concentrations. We determined 225 serum samples, and three patients receiving the treatment with interferon. In 102 HCV-RNA positive samples, significant correlation was observed between HCV-RNA and HCV-core antigen (r=0.734, p<0.0001). However, three out of 102 (2.9%) cases were included within the negative range of HCV-core antigen (20 fmol/l). The HCV-core antigen value in three patients receiving the treatment with interferon paralleled with the amount of HCV-RNA. The determination of HCV-core antigen by CLEIA is a useful and time-saving method, but an attention should be paid to the presence of false-negative cases.

Localization of retinal proteins in the stalk and dorsal eyes of the marine gastropod, Onchidium.

Onchidium possesses stalk eye (SE) and dorsal eye (DE) which comprise part of a unique multiple photoreceptive system. The retina of SE consists of rhabdomeric-type visual cells, whereas the DE contains two types of photoreceptor cells; ciliary-type cells in the retina and rhabdomeric-type cells in the lens. High-performance liquid chromatography (HPLC) analyses revealed the presence of 11-cis-retinal as well as all-trans-retinal in both eyes. The amount of retinal of one DE (0.17 pmol) is far less than that in one SE (0.41 pmol) in the dark-adapted Onchidium. In the dark-adapted SE, the amount of all-trans-retinal was higher than that of 11-cis-retinal. This finding is consistent with the presence of photic vesicles, including retinochrome, in rhabdomeric-type visual cells. In contrast, a higher amount of 11-cis-retinal than all-trans-retinal was present in dark-adapted DE, although this was decreased in light-adapted DE. Upon UV irradiation following treatment with sodium borohydride (NaBH(4)), the fluorescence (derived from retinochrome) was observed in the somatic layer of SE. Additional fluorescence (due to rhodopsin) was observed in the villous layer upon treatment with NaBH(4) after denaturation. However, only weak, obscure fluorescence of retinyl proteins was observed in the DE, not in a specific but an indefinite area on treatment with NaBH4 with or without denaturation. With fluorescence histochemistry, the localization of rhodopsin and retinochrome was confirmed at specific regions in the retina of the SE, whereas no distinct localization of these photopigments in DE was demonstrated. The amount of retinal to detect the fluorescence may be too low in the DE, or photopigments of DE may differ in chemical nature from those of SE.