Clinical application of targeted tumour sequencing tests for detecting ERBB2 amplification and optimizing anti-HER2 therapy in gastric cancer.

BACKGROUND: Evaluation of human epidermal growth factor receptor 2 (HER2) overexpression caused by erb-b2 receptor tyrosine kinase 2 (ERBB2) amplification (AMP) by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) is essential for treating unresectable metastatic gastric cancer (GC). A targeted tumour sequencing test enables comprehensive assessment of alterations in cancer-related genes, including ERBB2. This study aimed to evaluate the concordance between the targeted tumour sequencing test and IHC/FISH for detecting HER2-positive GC and to clarify the significance of ERBB2 AMP and concomitant genetic alterations in HER2 downstream pathways (DPs) in anti-HER2 therapy for unresectable metastatic GC patients. METHODS: ERBB2 copy number alteration (CNA) was examined via a targeted tumour sequencing test in 152 formalin-fixed paraffin-embedded (FFPE) GC tissues. ERBB2 CNA was compared to HER2 status evaluated by IHC/FISH in FFPE block sections, which were identical to those subjected to the targeted tumour sequencing test. Treatment outcomes of anti-HER2 therapy in 11 patients with unresectable metastatic GC was evaluated. RESULTS: ERBB2 AMP (≥ 2.5-fold change) was detected by the targeted tumour sequencing test in 15 patients (9.9%), and HER2 positivity (IHC 3 + or IHC 2+/FISH positive) was detected in 21 patients (13.8%). The overall percent agreement, positive percent agreement, negative percent agreement and Cohen's kappa between ERBB2 CNA and HER2 status were 94.7%, 66.7%, 99.2% and 0.75, respectively. Progression-free survival for trastuzumab therapy in patients with ERBB2 AMP was significantly longer than that in patients with no ERBB2 AMP detected by the targeted tumour sequencing test (median 14 months vs. 4 months, P = 0.007). Treatment response to trastuzumab therapy was reduced in patients with ERBB2 AMP and concomitant CNAs of genes in HER2 DPs. One patient with ERBB2 AMP and concomitant CNAs of genes in HER2 DPs achieved a durable response to trastuzumab deruxtecan as fourth-line therapy. CONCLUSIONS: A targeted tumour sequencing test is a reliable modality for identifying HER2-positive GC. ERBB2 AMP and concomitant genetic alterations detected through the targeted tumour sequencing test are potential indicators of treatment response to trastuzumab therapy. The targeted tumour sequencing test has emerged as a plausible candidate for companion diagnostics to determine indications for anti-HER2 therapy in the era of precision medicine for GC.

Macroscopic type is implicated in the prognostic impact of initial chemotherapy on peritoneal lavage cytology-positive gastric cancer with no other noncurative factors.

BACKGROUND: Initial chemotherapy (Initial-C) followed by surgery is a promising treatment strategy for peritoneal lavage cytology-positive gastric cancer (CY1 GC) with no other noncurative factors. The aim of this study was to investigate the survival advantage of Initial-C compared to initial surgery (Initial-S) for this disease according to the macroscopic type, which was associated with prognosis and the efficacy of chemotherapy in GC. METHODS: One hundred eighty-nine patients who were diagnosed with CY1 GC with no other noncurative factors at four institutions from January 2007 to December 2018 were enrolled. The patients were divided into a macroscopic type 4 group (N = 48) and a non-type 4 group (N = 141). The influence of initial treatment on overall survival (OS) in each group was evaluated. RESULTS: In the type 4 group, the 5-year OS rates of Initial-C (N = 35) and Initial-S (N = 13) were 11.6% and 0%, respectively (P = 0.801). The multivariate analysis could not show the survival advantage of Initial-C. In the non-type 4 group, the 5-year OS rates of Initial-C (N = 41) and Initial-S (N = 100) were 48.4% and 29.0%, respectively (P = 0.020). The multivariate analysis revealed that Initial-C was independently associated with prolonged OS (hazard ratio, 0.591; 95% confidence interval, 0.375-0.933: P = 0.023). CONCLUSIONS: Initial-C improves the prognosis of non-type 4 CY1 GC with no other noncurative factors. On the other hand, further development of effective chemotherapeutic regimens and innovative treatment strategies are required for type 4 CY1 GC.

TRPV1-positive sensory nerves and neuropeptides are involved in epidermal barrier repair after tape stripping in mice.

BACKGROUND: The integumentary system of the skin serves as an exceptional protective barrier, with the stratum corneum situated at the forefront. This outermost layer is composed of keratinocytes that biosynthesize filaggrin (encoded by the gene Flg), a pivotal constituent in maintaining skin health. Nevertheless, the precise role of sensory nerves in restoration of the skin barrier after tape stripping-induced epidermal disruption, in contrast to the wound-healing process, remains a tantalizing enigma. OBJECTIVE: This study aimed to elucidate the cryptic role of sensory nerves in repair of the epidermal barrier following tape stripping-induced disruption. METHODS: Through the implementation of resiniferatoxin (RTX)-treated denervation mouse model, we investigated the kinetics of barrier repair after tape stripping and performed immunophenotyping and gene expression analysis in the skin or dorsal root ganglia (DRG) to identify potential neuropeptides. Furthermore, we assessed the functional impact of candidates on the recovery of murine keratinocytes and RTX-treated mice. RESULTS: Ablation of TRPV1-positive sensory nerve attenuated skin barrier recovery and sustained subcutaneous inflammation, coupled with elevated IL-6 level in ear homogenates after tape stripping. Expression of the keratinocyte differentiation marker Flg in the ear skin of RTX-treated mice was decreased compared with that in control mice. Through neuropeptide screening, we found that the downregulation of Flg by IL-6 was counteracted by somatostatin or octreotide (a chemically stable somatostatin analog). Furthermore, RTX-treated mice given octreotide exhibited a partial improvement in barrier recovery after tape stripping. CONCLUSION: Sensory neurons expressing TRPV1 play an indispensable role in restoring barrier function following epidermal injury. Our findings suggest the potential involvement of somatostatin in restoring epidermal repair after skin injury.

Shape control of Au nanostructures using peptides for biotechnological applications.

Metallic gold (Au) nanostructures have attracted attentions in various fields of materials science and electrical science in terms of catalysts, sensing systems, photonic devices, and drug delivery systems because of their characteristic physical, chemical, and biocompatible properties. Recently, Au nanostructures with near-infrared light absorbing properties have shown potential for applications such as biological imaging and thermotherapy in biotechnological fields. However, fabrication of Au nanostructures with complex shapes often requires the use of highly biotoxic substances such as surfactants and reducing agents. Peptides are promising compounds for controlling the shape of Au nanostructures by mineralization with several advantages for this purpose. In this highlight, we focus on the shapes with respect to the fabrication of Au nanostructures using biocompatible peptides. We classify the peptides that form Au nanostructures into three broad categories: those that bind Au ions, those that reduce Au ions, and those that control the direction of Au crystal growth. Then, we briefly summarize the correlations between peptide sequences and their roles, and propose future strategies for fabricating Au nanostructures using peptides for biotechnological applications.

Effect of linearly polarized microwaves on nanomorphology of calcium carbonate mineralization using peptides.

Microwaves are used for diverse applications such as mobile phones, ovens, and therapy devices. However, there are few reports on the effects of microwaves on diseases other than cancer, and on physiological processes. Here, we focused on CaCO3 mineralization as a model of biomineralization and attempted to elucidate the effect of microwaves on CaCO3 mineralization using peptides. We conducted AFM, ζ potential, HPLC, ICP-AES, and relative permittivity measurements. Our findings show that microwaves alter the nanomorphology of the CaCO3 precipitate, from sphere-like particles to string-like structures. Furthermore, microwaves have little effect on the mineralization when the mineralization ability of a peptide is high, but a large effect when the precipitation ability is low. Our findings may be applicable to not only the treatment of teeth and bones but also the development of organic-inorganic nanobiomaterials. This methodology can be expanded to other molecular/atomic reactions under various microwave conditions to alter reaction activity parameters.

Ulcer Scarring in the Gastric Conduit Is a Risk Factor for Anastomotic Leakage After Esophagectomy for Esophageal Cancer.

BACKGROUND: Anastomotic leakage (AL) is a serious complication after esophagectomy for esophageal cancer. The objective of this study was to identify the risk factors for AL. METHODS: Patients with esophageal cancer who underwent curative esophagectomy and cervical esophagogastric anastomosis between 2009 and 2019 (N = 346) and those between 2020 and 2022 (N = 17) were enrolled in the study to identify the risk factors for AL and the study to assess the association between the risk factors and blood flow in the gastric conduit evaluated by indocyanine green (ICG) fluorescence imaging, respectively. RESULTS: AL occurred in 17 out of 346 patients (4.9%). Peptic or endoscopic submucosal dissection (ESD) ulcer scars were independently associated with AL (OR 6.872, 95% CI 2.112-22.365) in addition to diabetes mellitus. The ulcer scars in the anterior/posterior gastric wall were more frequently observed in patients with AL than in those without AL (75.0% vs. 17.4%, P = 0.042). The median flow velocity of ICG fluorescence in the gastric conduits with the scars was significantly lower than in those without the scars (1.17 cm/s vs. 2.23 cm/s, P = 0.004). CONCLUSIONS: Peptic or ESD ulcer scarring is a risk factor for AL after esophagectomy in addition to diabetes mellitus. The scars in the anterior/posterior gastric wall are significantly associated with AL, impairing blood flow of the gastric conduit. Preventive interventions and careful postoperative management should be provided to minimize the risk and severity of AL in patients with these risk factors.

[A Case of Esophageal Carcinoma with Tracheal Invasion after Preoperative Treatment with Docetaxel, Cisplatin, and 5-Fluorouracil in Which Definitive Chemoradiotherapy and Salvage Esophagectomy Prolonged Survival].

A 57-year-old man was diagnosed as having resectable advanced esophageal carcinoma adjacent to the trachea(Ut, cT3N0M0)and received preoperative docetaxel, cisplatin, and 5-fluorouracil therapy. Due to tracheal tumor invasion and upstaging to cT4bN0M0 after 1 course of chemotherapy, the treatment was converted to definitive chemoradiotherapy (CRT). A remarkable response with no evidence of tracheal invasion was observed on computed tomography following definitive CRT. He underwent successful curative resection with salvage esophagectomy, and the resected tumor was staged as pT1bN0M0. No adjuvant therapy was administered, and the patient was alive with no evidence of disease at the 5-year postoperative follow-up. The response to preoperative treatment should be meticulously assessed and appropriate treatment modalities used to avoid overlooking the potential for cure, even if the response to preoperative treatment with docetaxel, cisplatin, and 5-fluorouracil is poor.

De novo design of a nanopore for single-molecule detection that incorporates a ß-hairpin peptide.

The amino-acid sequence of a protein encodes information on its three-dimensional structure and specific functionality. De novo design has emerged as a method to manipulate the primary structure for the development of artificial proteins and peptides with desired functionality. This paper describes the de novo design of a pore-forming peptide, named SV28, that has a ß-hairpin structure and assembles to form a stable nanopore in a bilayer lipid membrane. This large synthetic nanopore is an entirely artificial device for practical applications. The peptide forms multidispersely sized nanopore structures ranging from 1.7 to 6.3 nm in diameter and can detect DNAs. To form a monodispersely sized nanopore, we redesigned the SV28 by introducing a glycine-kink mutation. The resulting redesigned peptide forms a monodisperse pore with a diameter of 1.7 nm leading to detection of a single polypeptide chain. Such de novo design of a ß-hairpin peptide has the potential to create artificial nanopores, which can be size adjusted to a target molecule.

[A Case of Unresectable Advanced Gastric Cancer Resected by Conversion Surgery after Trastuzumab Combination Chemotherapy].

A 74-year-old man presented to our hospital with a mass in the left supraclavicular fossa. He was diagnosed with advanced gastric cancer with liver metastasis and left supraclavicular and para-aortic lymph node metastasis, cT3N2M1 (LYM, HEP), cStage Ⅳ(the Union for International Cancer Control, TNM 7th edition). He received a total of 3 courses of S- 1 plus cisplatin therapy. Since he developed adverse reactions such as anorexia, renal dysfunction, and thrombocytopenia and the tumor was HER2-positive, he received 25 courses of capecitabine, cisplatin, and trastuzumab chemotherapy. Three years and 2 months after the first chemotherapy, remarkable tumor reduction was observed. The patient then underwent radical distal gastrectomy with D2 lymphadenectomy, and R0 resection was achieved. The histopathological diagnosis was ypT1aN0M0, ypStage ⅠA. Chemotherapy with trastuzumab may improve the long-term prognosis of HER2-positive Stage Ⅳ gastric cancer if the disease is controlled and radical resection can be achieved.

Accuracy of the endoscopic evaluation of esophageal involvement in esophagogastric junction cancer.

BACKGROUND: Esophageal involvement length (EIL) is a promising indicator of metastasis or recurrence in mediastinal lymph nodes (MLNs) in adenocarcinoma of the esophagogastric junction (EGJ). This study aimed to elucidate the accuracy of the preoperative endoscopic evaluations of EIL and its clinical significance in this disease. MATERIALS AND METHODS: In total, 75 patients with Siewert type II (N = 53) or III (N = 22) adenocarcinoma of the EGJ, who underwent surgical resection without preoperative therapy between 1995 and 2016 were enrolled. We retrospectively examined the accuracy of the preoperative endoscopic evaluations of EIL (preoperative EIL), compared to the pathologically evaluated EIL. Finally, we investigated the association between preoperative EIL and metastasis or recurrence in MLNs. RESULTS: The accuracy of the preoperative EIL within a 1-cm interval was only 53.3%. Among patients with discordance between the pre- and postoperative evaluations, 68.6 % had the underestimation in the preoperative EIL. pN1-3 (OR = 5.85, 95% CI: 1.03-33.17) and undifferentiated histologic type (OR = 2.52, 95% CI: 0.89-7.14) were potential risk factors for the discordance. Regarding metastasis or recurrence in MLNs, preoperative EIL of 2-3 cm (OR = 10.41, 95% CI: 1.35-80.11) and >3 cm (OR = 8.33, 95% CI: 1.09-63.96) were independent predictors. CONCLUSION: Although the accuracy of the endoscopic evaluations of EIL is insufficient with many underestimations, EIL should be assessed in preoperative staging because of significant predictive power for metastasis or recurrence in MLNs.

Mass Spectrometry-Based Solid Phase Peptide Reaction Assay for Detecting Allergenicity Using an Immobilized Peptide-Conjugating Photo-Cleavable Linker.

The biological process of skin sensitization depends on the ability of a sensitizer to modify endogenous proteins. A direct peptide reactivity assay (DPRA), based on the biological process of skin sensitization, was developed as an alternative to controversial animal experiments. Although DPRA has been endorsed by industries and is internationally accepted as promising, it has several drawbacks, such as incompatibility with hydrophobic chemicals, inability to perform detailed reaction analysis, and ability to evaluate only single components. Here, we demonstrated that sensitizers and peptide adducts can be easily identified using a mass spectrometry-based solid-phase peptide reaction assay (M-SPRA). We synthesized peptides with a photo-cleavable linker immobilized on resins. We showed the potential of M-SPRA in predicting skin sensitization by measuring the peptide adducts that were selectively eluted from the resin after cleaving the linker post-reaction. M-SPRA provides more detailed information regarding chemical reactivity and accurate assessment of test samples, including mixtures. M-SPRA may be helpful for understanding the binding mechanism of sensitizers (toxicology), which may assist in further refining reactivity assays and aiding in the interpretation of reactivity data.

Development of a chromophore-solid phase peptide reaction assay (C-SPRA) for assessing skin sensitization in vitro.

We developed an in vitro chromophore-solid phase peptide reaction assay (C-SPRA) using microbead-immobilized peptides and chromophores. Peptide-resins (microbeads) reacted with 14 representative chemicals to demonstrate the test's capacity to predict skin sensitization. C-SPRA enables accurate and high-throughput assessments of various chemicals, including poorly water-soluble sensitizers that are regarded as weakly potent by other methods.

Primary lung squamous cell carcinoma and its association with gastric metastasis: A case report and literature review.

Nearly 50% of primary lung carcinoma patients present with distant metastasis at their first visit. However, gastrointestinal tract (GIT) metastasis is an infrequent impediment. Herein, we report a case of progressive dysphagia and epigastralgia as an initial manifestation of recurrence as gastric metastasis of primary lung squamous cell carcinoma (SCC) after curative surgery. A 64-year-old man was diagnosed with primary lung SCC of the right lower lobe, and underwent thoracoscopic lower lobectomy. One year after lobectomy, computed tomography (CT) scan showed a gastric fundal mass located in the gastric cardia which measured 5 cm. Endoscopic biopsies and histopathology subsequently confirmed that tumor was SCC. The patient then underwent proximal gastrectomy with resection of the diaphragmatic crus. Following surgery, histopathological examination revealed gastric metastasis from primary lung SCC. KEY POINTS: Gastric metastasis of primary lung carcinoma is one of the rarest phenomena. Gastrointestinal symptoms should raise suspicion of the presence of advanced metastatic disease with poor prognosis.

[A Case of Esophageal Cancer Achieving a Pathological Complete Response after Preoperative Docetaxel, Cisplatin, and 5-Fluorouracil Therapy].

A 66-year-old man with middle thoracic esophageal squamous cell carcinoma with supraclavicular lymph node metastasis visited our hospital. He underwent 3 courses of preoperative chemotherapy with docetaxel, cisplatin, and 5-FU(DCF)with a clinically-determined partial response. Minimally-invasive esophagectomy with 3-fieldlymphad enectomy was subsequently performed. Histopathologic examination revealedno viable tumor cells in the resectedesophagus andsupraclavicular lymph node. DCF is a promising preoperative chemotherapy regimen for locally advanced esophageal cancer because of its higher complete response rate comparedto that for cisplatin plus 5-FU.

[A Case of Esophageal Primary Malignant Melanoma That Developed During the Follow-Up of Esophageal Melanocytosis].

A 78-year-old woman was endoscopically followed up for benign melanocytosis in the middle thoracic esophagus that was detected 3 years prior. She presented with chest tightness, and an endoscopic examination revealed a protruding tumor at the melanotic lesion. She was histologically diagnosedwith an esophageal primary malignant melanoma. Computedtomography showedno metastatic lesions. She underwent minimally invasive esophagectomy with 2-fieldlymphad enectomy. Immunotherapy with nivolumab is ongoing for liver metastasis, which developed1 year and6 months after esophagectomy. Careful follow-up for esophageal melanocytosis is important for early diagnosis of esophageal primary malignant melanoma.

Channel current analysis estimates the pore-formation and the penetration of transmembrane peptides.

We measured the current signal of the transmembrane model peptides using the barrel-stave, toroidal pore, and penetration models in order to establish a precise assignment of the channel signals. In addition, we analyzed the spike signals to estimate the membrane penetration of model cell-penetration peptides of different lengths.

Applications of a novel biodetection system to saliva using protein fingerprints with data processing.

A fundamental method has been developed focusing on a facile and rapid examination of periodontal disease. Periodontal disease is an oral disease thought to affect 80% of adults, and early detection with treatment is desirable for the improvement of the quality of life. Unfortunately conventional methods are not consistent as the disease is caused by a number of undefined bacteria and detection relies on the skills of the dentist. Thus an objective detection system is required. We have performed an experiment on saliva using a novel biodetection system, designated PepTenChip®. A disease model for saliva was prepared using a specimen from a healthy subject and a mixture of hemoglobin (f-Hb) and lactate dehydrogenase (LDH), which is used as a periodontal disease marker protein with healthy saliva. PepTenChip® is a peptide microarray in which fluorescent labelled structured peptides are immobilized on a novel amorphous carbon substrate. Since the peptides used as capture molecules are fluorescently labelled, labeling of analytes is not necessary. The fluorescence intensity change before and after application of analytes are detected rather than the ON/OFF detection common to conventional microarrays using a set of antigen-antibody. The fluorescence intensity value changes according to the concentration of captured protein allowing the generation of protein fingerprint (PFP) and dendrograms. The present method does not rely on a "one to one" interaction, unlike conventional biodetection, and advantages can be envisaged in the case of an undefined or unknown cause of disease. The statistical analyses, such as multivariate analyses, allow classification of the type of proteins added in saliva as mimetics of disease. PepTenChip® system is useful and convenient for examination of periodontal disease in health care.

Modification of the N-Terminus of a Calcium Carbonate Precipitating Peptide Affects Calcium Carbonate Mineralization.

BACKGROUND: A core sequence (the 9 C-terminal residues) of calcification-associated peptide (CAP- 1) isolated from the exoskeleton of the red swamp crayfish was previously shown to control calcium carbonate precipitation with chitin. In addition, a modified core sequence in which the phosphorylated serine at the N terminus is replaced with serine exhibits was also previously shown to alter precipitation characteristics with chitin. OBJECTIVES: We focused on calcium carbonate precipitation and attempted to elucidate aspects of the mechanism underlying mineralization. We attempted to evaluate in detail the effects of modifying the N-terminus in the core sequence on calcium carbonate mineralization without chitin. METHODS: The peptide modifications included phosphorylation, dephosphorylation, and a free or acetylated Nterminus. The peptides were synthesized manually on Wang resin using the DIPCI-DMAP method for the first residue, and Fmoc solid phase peptide synthesis with HBTU-HOBt for the subsequent residues. Prior to calcium carbonate precipitation, calcium carbonate was suspended in MilliQ water. Carbon dioxide gas was bubbled into the stirred suspension, then the remaining solid CaCO3 was removed by filtration. The concentration of calcium ions in the solution was determined by standard titration with ethylenediaminetetraacetate. Calcium carbonate precipitation was conducted in a micro tube for 3 h at 37°C. We used the micro-scale techniques AFM (atomic force microscopy) and TEM (transmission electron microscopy), and the macro-scale techniques chelate titration, HPLC, gel filtration, CD (circular dichroism) and DLS (dynamic light scattering). RESULTS: We determined the morphologies of the calcium carbonate deposits using AFM and TEM. The pS peptide provided the best control of the shape and size of the calcium carbonate round particles. The acetylated peptides (Ac-S and Ac-pS) provided bigger particles with various shapes. S peptide provided a mixture of bigger particles and amorphous particles. We verified these findings using DLS. All the peptide samples produced nanostructures of the expected size in agreement with the AFM and TEM results. We estimated the abilities of these peptides to precipitate calcium carbonate by determining the residual calcium hydrogen carbonate concentration by standard titration with ethylenediaminetetraacetate after calcium carbonate precipitation. The Ac-pS peptide showed the lowest residual calcium hydrogen carbonate concentration whereas the S peptide showed the highest, suggesting that the precipitating activities of these peptides towards calcium carbonate correlated with peptide net charge. Then the gel filtration results showed a large oligomer peak and a small oligomer/monomer peak for all peptide samples in agreement with the AFM, TEM and DLS results. CD measurements showed that all the peptides formed random-coil-like structures. Thus, we used both macro- and micro-observation techniques such as chelate titration, DLS, AFM and TEM to show that the calcium carbonate precipitating activities of four derivatives of the core sequence of CAP-1 may correlate with the peptide net charge. CONCLUSION: These peptides mainly act as a catalyst rather than as a binder or component of the calcium carbonate deposits (as a template). On the other hand, the morphologies of the calcium carbonate deposits appeared to be dependent on the ability of the peptide to assemble and act as a template. Consequently, elucidating the relationship between peptide sequence and the ability of the peptide to assemble would be indispensable for controlling precipitate morphologies in the near future. This knowledge would provide important clues for elucidating the relationship between peptide sequence and mineralization ability, including deposit morphology and precipitating activity, for use in nanobiochemistry and materials chemistry research.

Peptides for Silica Precipitation: Amino Acid Sequences for Directing Mineralization.

BACKGROUND: Peptides are promising compounds for use in inorganic or organic-inorganic hybrid syntheses (mineralization) and offer several advantages over proteins. Meanwhile, silica-based nanomaterials have been extensively investigated for many years because of their potential application in a diverse range of technologies, including catalysis, sensing, separation, enzyme immobilization, and gene and drug delivery. Considerable progress has been made over the past decade in understanding the molecular mechanisms underpinning biosilicification and the biomimetic synthesis of patterned nanosilica using peptides. OBJECTIVES: This mini-review focuses on various peptide sequences, especially short peptide sequences (30 residues or less), for silica mineralization. METHODS: We first briefly review early studies on silica mineralization using proteins to provide background information. This is followed by a discussion of promising peptide sequences and attempts to discern the relationship between amino acid sequence, their potential for mineralization, and the properties of the mineral product. RESULTS: The synthetic control of silica mineralization using engineered proteins, such as recombinant silicateins and silaffins, was inspired by silica biomineralization by natural proteins from organisms (sponges, diatoms, and plants). Concurrently, several papers described the utility of well-structured protein assemblies as templates for silica mineralization. These template-directed syntheses of well-structured silica deposits were first conducted using natural proteins or protein assemblies such as collagen fibers and virus hollow protein tubes. Then we reviewed a selection of short peptides (30 residues or less) that had been successfully used for silica mineralization. Almost all peptides developed to date can be sorted by classification like proteins (synthetic control of silica mineralization or utility of templates for silica mineralization): the first class of peptides is used for peptide-directed synthesis, and the second is used for template-directed synthesis after the peptides have assembled and formed nanostructure such as fibers and tubes. The presented peptides were classified and arranged according to the classification. Additionally, we briefly introduced silica mineralization triggered by the combination of short silica-precipitating peptides and template molecules. CONCLUSION: In this mini-review we focused on various peptide sequences, especially short peptide sequences of 30 residues or less, designed for silica mineralization. The peptides have been used both for peptide-directed silica mineralization and for template-directed silica mineralization. The recent advances in peptide-driven mineralization reviewed here suggest that it will soon be possible to completely control the silica mineralization process using peptides. Mineralization systems using peptides will provide researchers with new tools for controlling various inorganic syntheses and the production of organic-inorganic materials for nanobiochemistry and materials chemistry research.

[Chemoresistance in Microsatellite Instability-High Gastric Cancer-A Case Report].

A 74-year-old woman with cT4aN2M0, cStage ⅢB gastric cancer underwent neoadjuvant chemotherapy comprising 2 courses of S-1 plus cisplatin, and the clinical response was determined as non-CR/non-PD according to RECIST ver 1.1. Although distal gastrectomy with D2 lymphadenectomy was planned, the tumor was considered as unresectable with peritoneal metastases during laparotomy. After the subsequent chemotherapy with 1 course of capecitabine plus cisplatin, tumor bleeding, and obstruction due to rapid tumor progression occurred. We performed palliative distal gastrectomy; however, the patient died 17 days after gastrectomy. A comprehensive genomic analysis using cancer-gene panel identified the tumor as a microsatellite instability-high(MSI-H). Recently post hoc analysis of the large-scale clinical trials showed no clinical benefit of perioperative chemotherapy in MSI-H gastric cancer. MSI status has a potential to optimize the perioperative treatment strategy in gastric cancer.