In vivo subcellular imaging of tumors in mouse models using a fluorophore-conjugated anti-carcinoembryonic antigen antibody in two-photon excitation microscopy

Recently, there has been growing interest in applying fluorescence imaging techniques to the study of various disease processes and complex biological phenomena in vivo. To apply these methods to clinical settings, several groups have developed protocols for fluorescence imaging using antibodies against tumor markers conjugated to fluorescent substances. Although these probes have been useful in macroscopic imaging, the specificity and sensitivity of these methods must be improved to enable them to detect micro-lesions in the early phases of cancer, resulting in better treatment outcomes. To establish a sensitive and highly specific imaging method, we used a fluorophore-conjugated anti-carcinoembryonic antigen (CEA) antibody to perform macroscopic and microscopic in vivo imaging of inoculated cancer cells expressing GFP with or without CEA. Macroscopic imaging by fluorescence zoom microscopy revealed that bio-conjugation of Alexa Fluor 594 to the anti-CEA antibody allowed visualization of tumor mass consisting of CEA-expressing human cancer cells, but the background levels were unacceptably high. In contrast, microscopic imaging using a two-photon excitation microscope and the same fluorescent antibody resulted in subcellular-resolution imaging that was more specific and sensitive than conventional imaging using a fluorescence zoom microscope. These results suggest that two-photon excitation microscopy in conjunction with fluorophore-conjugated antibodies could be widely adapted to detection of cancer-specific cell-surface molecules, both in cancer research and in clinical applications

p70S6K/Akt dual inhibitor DIACC3010 is efficacious in preclinical models of gastric cancer alone and in combination with trastuzumab

Abstract The PI3K-Akt-mTOR (PAM) pathway is implicated in tumor progression in many tumor types, including metastatic gastric cancer (GC). The initial promise of PAM inhibitors has been unrealized in the clinic, presumably due, in part, to the up-regulation of Akt signaling that occurs when the pathway is inhibited. Here we present that DIACC3010 (formerly M2698), an inhibitor of two nodes in the PAM pathway, p70S6K and Akt 1/3, blocks the pathway in in vitro and in vivo preclinical models of GC while providing a mechanism that inhibits signaling from subsequent Akt up-regulation. Utilizing GC cell lines and xenograft models, we identified potential markers of DIACC3010-sensitivity in Her2-negative tumors, i.e., PIK3CA mutations, low basal pERK, and a group of differentially expressed genes (DEGs). The combination of DIACC3010 and trastuzumab was evaluated in Her2-positive cell lines and models. Potential biomarkers for the synergistic efficacy of the combination of DIACC3010 + trastuzumab also included DEGs as well as a lack of up-regulation of pERK. Of 27 GC patient-derived xenograft (PDX) models tested in BALB/c nu/nu mice, 59% were sensitive to DIACC3010 + trastuzumab. Of the 21 HER2-negative PDX models, DIACC3010 significantly inhibited the growth of 38%. Altogether, these results provide a path forward to validate the potential biomarkers of DIACC3010 sensitivity in GC and support clinical evaluation of DIACC3010 monotherapy and combination with trastuzumab in patients with HER2- negative and positive advanced GCs, respectively

限局性前立腺癌に対する高密度焦点式超音波療法:多施設共同研究

限局性前立腺癌に対する高密度焦点式超音波療法の多施設共同研究の成績について報告した.対象は, stageT1-2N0M0の72例の限局性前立腺癌で, 症例の年齢中央値は72歳, 血清PSA中央値は8.10n/mlであった.その結果, 治療効果は全体では1年78%, 2年76%が非再発生存であった.浸潤度別に2年目の生化学的非再発生存率を集計したところ, stage T1cが89%, stage T2a 67%, stage T2bは40%(p=0.0817)であった.悪性度別では, Gleason 2～4群は88%, Gleason 5～7群は72%, Gleason 8～10群は80%(p=0.6539)であった.術前の血清PSA値別2年非再発生存率は, PSAが10ng/ml以下群は75%, 10～20ng/ml群は78%(p=0.6152)であった.術後6ヵ月目の前立腺生検では68%において癌細胞は認められなかった.前立腺体積は, 術前24.2mlから術後6ヵ月目14.0mlと縮小していた(p<0.01).IPSS, 最大尿流量率, Functional Assessment of Cancer Therapy(FACT)を用いた生活の質項目は術前後に有意な変化は認められなかった.以上, 高密度焦点式超音波療法は, 術前血清PSA値が20ng/ml以下の限局性前立腺癌に対して低侵襲性でかつ有用な治療法だと思われたWe report a multicenter trial with transrectal high-intensity focused ultrasound (HIFU) in the treatment of localized prostate cancer. A total of 72 consecutive patients with stage T1c-2NOM0 prostate cancer were treated using the Sonablate 500TM HIFU device (Focus Surgery, Indianapolis, USA). Biochemical recurrence was defined according to the criteria recommended by the American Society for Therapeutic Radiology and Oncology Consensus Panel. The median age and prostate specific antigen (PSA) level were 72 years and 8.10 ng/ml, respectively. The median follow-up period for all patients was 14.0 months. Biochemical disease-free survival rates in all patients at 1 and 2 years were 78% and 76%, respectively. Biochemical disease-free survival rates in patients with stage T1c, T2a and T2b groups at 2 years were 89, 67% and 40% (p = 0.0817). Biochemical disease-free survival rates in patients with Gleason scores of 2-4, 5-7 and 8-10 at 2 years were 88, 72% and 80% (p = 0.6539). Biochemical disease-free survival rates in patients with serum PSA of less than 10 ng/ml and 10-20 ng/ml were 75% and 78% (p = 0.6152). No viable tumor cells were noted in 68% of patients by postoperative prostate needle biopsy. Prostatic volume was decreased from 24.2 ml to 14.0 ml at 6 months after HIFU (p < 0.01). No statistically significant differences were noted in International Prostate Symptom Score, maximum urinary flow rate and quality of life analysis with Functional Assessment of Cancer Therapy. HIFU therapy appears to be minimally invasive, efficacious and safe for patients with localized prostate cancer with pretreatment PSA levels less than 20 ng/ml

Differences among epitopes recognized by neutralizing antibodies induced by SARS-CoV-2 infection or COVID-19 vaccination

Summary: SARS-CoV-2 has gradually acquired amino acid substitutions in its S protein that reduce the potency of neutralizing antibodies, leading to decreased vaccine efficacy. Here, we attempted to obtain mutant viruses by passaging SARS-CoV-2 in the presence of plasma samples from convalescent patients or vaccinees to determine which amino acid substitutions affect the antigenicity of SARS-CoV-2. Several amino acid substitutions in the S2 region, as well as the N-terminal domain (NTD) and receptor-binding domain (RBD), affected the neutralization potency of plasma samples collected from vaccinees, indicating that amino acid substitutions in the S2 region as well as those in the NTD and RBD affect neutralization by vaccine-induced antibodies. Furthermore, the neutralizing potency of vaccinee plasma samples against mutant viruses we obtained or circulating viruses differed among individuals. These findings suggest that genetic backgrounds of vaccinees influence the recognition of neutralizing epitopes