Adaptation of STIM1 structure-function relationships for optogenetic control of calcium signaling.

In cellular contexts, the oscillation of calcium ions (Ca2+) is intricately linked to various physiological processes, such as cell proliferation, metabolism, and survival. Stromal interaction molecule 1 (STIM1) proteins form a crucial regulatory component in the store-operated calcium entry (SOCE) process. The structural attributes of STIM1 are vital for its functionality, encompassing distinct domains situated in the endoplasmic reticulum (ER) lumen and the cytoplasm. The intraluminal domain enables the timely detection of diminishing Ca2+ concentrations, prompting structural modifications that activate the cytoplasmic domain. This activated cytoplasmic domain undergoes conformational alterations and engages with membrane components, opening a channel that facilitates the influx of Ca2+ from the extracellular environment. Given its multiple domains and interaction mechanisms, STIM1 plays a foundational role in cellular biology. This review focuses on the design of optogenetic tools inspired by the structure and function of STIM1. These tools offer a groundbreaking approach for studying and manipulating intracellular Ca2+ signaling with precisely spatiotemporal control. We further explore the practical applications of these tools, spanning fundamental scientific research, clinical studies, and their potential for translational research.

Atlas of metastatic gastric cancer links ferroptosis to disease progression and immunotherapy response.

BACKGROUND & AIMS: Metastases from gastric adenocarcinoma (GAC) lead to high morbidity and mortality. Developing innovative and effective therapies requires a comprehensive understanding of the tumor and immune biology of advanced GAC. Yet, collecting matched specimens from advanced, treatment-naïve GAC patients poses a significant challenge, limiting the scope of current research, which has predominantly focused on localized tumors. This gap hinders a deeper insight into the metastatic dynamics of GAC. METHODS: We performed in-depth single-cell transcriptome and immune profiling on 68 paired, treatment-naïve, primary-metastatic tumors to delineate alterations in cancer cells and their tumor microenvironment (TME) during metastatic progression. To validate our observations, we conducted comprehensive functional studies both in vitro and in vivo, employing cell lines, multiple PDX and novel mouse models of GAC. RESULTS: Liver and peritoneal metastases exhibited distinct properties in cancer cells and dynamics of TME phenotypes, supporting the notion that cancer cells and their local TMEs co-evolve at metastatic sites. Our study also revealed differential activation of cancer meta-programs across metastases. We observed evasion of cancer cell ferroptosis via GPX4 upregulation during GAC progression. Conditional depletion of Gpx4 or pharmacological inhibition of ferroptosis resistance significantly attenuated tumor growth and metastatic progression. Additionally, ferroptosis-resensitizing treatments augmented the efficacy of CAR T-cell therapy. CONCLUSIONS: This study represents the largest single-cell dataset of metastatic GACs to date. High-resolution mapping of the molecular and cellular dynamics of GAC metastasis has revealed a rationale for targeting ferroptosis defense in combination with CAR T-cell therapy as a novel therapeutic strategy with potential immense clinical implications.

Pretreatment Pan-Immune-Inflammation Value (PIV) in Predicting Therapeutic Response and Clinical Outcomes of Neoadjuvant Immunochemotherapy for Esophageal Squamous Cell Carcinoma.

PURPOSE: The pan-immune-inflammation value (PIV), which reflects the balance between the host immune and inflammatory status, is a readily available index for evaluating cancer outcomes. Until now, however, no study has demonstrated the clinical response of PIV to neoadjuvant immunochemotherapy (NICT) in esophageal squamous cell carcinoma (ESCC). METHODS: This retrospective study included 218 patients with ESCC who underwent NICT. The relationship between PIV and therapeutic response (pathological complete response [PCR]) and clinical outcomes (overall survival [OS] and disease-free survival [DFS]) was examined. Cox proportional, hazard-regression analyses and the Kaplan-Meier method were used for survival analyses. Recursive partitioning analysis (RPA) was used to establish a novel risk stratification model. RESULTS: Sixty-six patients (30.3%) achieved PCR after NICT. Using PCR as the endpoint of interest, patients were compared in groups based on the optimal threshold. PIV was closely related to PCR (odds ratio [OR] 0.311, 95% confidence interval [CI] 0.140-0.690, P = 0.004). Compared with patients in the low PIV cohort, patients with high PIV had worse 3-year OS (58.7% vs. 83.6%, P < 0.001) and DFS (51.9% vs. 79.1%, P < 0.001). PIV was an independent predictor of OS (hazard ratio [HR] 2.364, 95% CI 1.183-4.724, P = 0.015) and DFS (HR 1.729, 95% CI 1.026-2.913, P = 0.040). Three risk groups with varied DFS and OS were staged by using an RPA method, and the prognostication accuracy was considerably improved. CONCLUSIONS: Pretreatment PIV can predict the therapeutic efficacy of NICT for ESCC. Because of better prognostic stratification, pretreatment PIV is a novel, sensitive, and effective indicator in ESCC receiving NICT. The prognostic results of PIV need to be verified in additional prospective studies.

Development and validation of nomogram for predicting early recurrence after radical gastrectomy of gastric cancer.

BACKGROUND: After radical surgery, early detection of recurrence and metastasis is a crucial factor in enhancing the prognosis and survival of patients with gastric cancer (GC). Therefore, assessing the risk of recurrence in gastric cancer patients and determining the timing for postoperative recurrence is crucial. METHODS: The clinicopathological data of 521 patients with recurrent gastric cancer, who underwent radical gastrectomy at Zhejiang Cancer Hospital between January 2010 and January 2017, were retrospectively analyzed. These patients were randomly divided into two groups: a training group (n = 365) and a validation group (n = 156). In the training set, patients were further categorized into early recurrence (n = 263) and late recurrence (n = 102) groups based on a 2-year boundary. Comparative analyses of clinicopathological features and prognoses were conducted between these two groups. Subsequently, a nomogram for predicting early recurrence was developed and validated. RESULTS: In this study, the developed nomogram incorporated age, serous infiltration, lymph node metastasis, recurrence mode, and the tumour marker CA19-9. In the training cohort, the area under the curve (AUC value) was 0.739 (95% CI, 0.682-0.798), with a corresponding C-index of 0.739. This nomogram was subsequently validated in an independent validation cohort, yielding an AUC of 0.743 (95% CI, 0.652-0.833) and a C-index of 0.743. Furthermore, independent risk factors for prognosis were identified, including age, absence of postoperative chemotherapy, early recurrence, lymph node metastasis, abdominal metastasis, and vascular cancer embolus. CONCLUSION: Independent risk factors for gastric cancer recurrence following radical surgery were utilized to construct a nomogram for predicting early relapse. This nomogram effectively assesses the risk of recurrence, aids in treatment decision-making and follow-up planning in clinical settings, and demonstrated strong performance in the validation cohort.

Protein Tyrosine Phosphatase PRL-3: A Key Player in Cancer Signaling.

Protein phosphatases are primarily responsible for dephosphorylation modification within signal transduction pathways. Phosphatase of regenerating liver-3 (PRL-3) is a dual-specific phosphatase implicated in cancer pathogenesis. Understanding PRL-3's intricate functions and developing targeted therapies is crucial for advancing cancer treatment. This review highlights its regulatory mechanisms, expression patterns, and multifaceted roles in cancer progression. PRL-3's involvement in proliferation, migration, invasion, metastasis, angiogenesis, and drug resistance is discussed. Regulatory mechanisms encompass transcriptional control, alternative splicing, and post-translational modifications. PRL-3 exhibits selective expressions in specific cancer types, making it a potential target for therapy. Despite advances in small molecule inhibitors, further research is needed for clinical application. PRL-3-zumab, a humanized antibody, shows promise in preclinical studies and clinical trials. Our review summarizes the current understanding of the cancer-related cellular function of PRL-3, its prognostic value, and the research progress of therapeutic inhibitors.

Clinical significance of geriatric nutritional risk index in esophageal squamous cell carcinoma receiving neoadjuvant immunotherapy.

OBJECTIVE: The geriatric nutritional risk index (GNRI) is a novel nutrition-related indicator designed to predict the risk of clinical outcomes in various cancers. The clinical significance of risk assessment, therapeutic response, and prognostic prediction of GNRI in esophageal squamous cell carcinoma (ESCC) receiving neoadjuvant immunochemotherapy (NICT), a hot point of treatment these days, have not been documented in any research. METHODS: Two hundred and twenty-four cases with ESCC who underwent radical resection after NICT were retrospectively recruited. Using the calculation formula of GNRI (1.489 × albumin (g/L) + 41.7 × current weight/ideal weight), the cases were split into two cohorts. Analysis was done on the connections between GNRI and clinical outcomes, such as clinical features, postoperative complications, and pathological complete response (pCR). Prognostic factors of overall survival (OS) and disease-free survival (DFS) were also performed. RESULTS: Patients were then categorized as low (n = 139) or high (n = 85) group based on the threshold. After radical surgery, 67 patients achieved pCR (29.9%). Higher pCR rates were attained by patients in the high GNRI group (41.2% vs. 23.0%, P = 0.004). Lower GNRI patients experienced a considerably higher severe morbidity (36.7% vs. 23.5%, P = 0.040), particularly in the case of respiratory complications (28.8% vs. 14.1%, P = 0.012). Compared to high GNRI patients, lower GNRI cases had inferior 3-year OS (68.5% vs. 87.3%, P = 0.003) and DFS (64.8% vs. 81.5%, P = 0.002). It was also discovered that GNRI was a significant independent variable of both DFS [hazard ratios (HR) = 0.436, P = 0.009] and OS (HR = 0.294, P = 0.012). CONCLUSION: The GNRI, based on nutrition-related indicators, was independently related to postoperative complications, pCR prediction, and prognostication in ESCC receiving NICT.

Genomic biology and therapeutic strategies of liver metastasis from gastric cancer.

The liver is a frequent site of metastasis in advanced gastric cancer (GC). Despite significant advancements in diagnostic and therapeutic techniques, the overall survival rate for patients afflicted with gastric cancer liver metastasis (GCLM) remains dismally low. Precision oncology has made significant progress in identifying therapeutic targets and enhancing our understanding of metastasis mechanisms through genome sequencing and molecular characterization. Therefore, it is crucial to have a comprehensive understanding of the various molecular processes involved in GCLM and the fundamental principles of systemic therapy to develop new treatment approaches. This paper aims to review recent findings on the diagnosis, potential biomarkers, and therapies targeting the multiple molecular processes of GCLM, with the goal of improving treatment strategies for patients with GCLM.

Cancer survival analysis on population-based cancer registry data in Zhejiang Province, China (2018-2019).

Objective: This is a comprehensive overview of long-term cancer survival in Zhejiang Province, China. Hybrid analysis, a combination of cohort and period analysis, has been proposed to derive up-to-date cancer survival estimates. Using this approach, we aimed to timely and accurately analyze the 5-year relative survival (RS) and net survival (NS) in cancer registries of Zhejiang Province, China. Methods: A total of 255,725 new cancer cases diagnosed during 2013-2017 were included in 14 cancer registries in Zhejiang Province, China, with a follow-up on vital status until the end of 2019. The hybrid analysis was used to calculate the 5-year RS and 5-year NS during 2018-2019 for overall and stratifications by sex, cancer type, region, and age at diagnosis. Results: During 2018-2019, the age-standardized 5-year RS and NS for overall cancer in Zhejiang was 47.5% and 48.6%, respectively. The age-standardized 5-year RS for cancers of women (55.4%) was higher than that of men (40.0%), and the rate of urban areas (49.7%) was higher than that of rural areas (43.1%). The 5-year RS declined along with age, from 84.4% for ages <45 years to 23.7% for ages >74 years. Our results of the RS and NS showed the similar trend and no significant difference. The top five cancers with top age-standardized 5-year RS were thyroid cancer (96.0%), breast cancer (84.3%), testicular cancer (79.9%), prostate cancer (77.2%), and bladder cancer (70.6%), and the five cancers with the lowest age-standardized 5-year RS were pancreatic cancer (6.0%), liver cancer (15.6%), gallbladder cancer (17.1%), esophageal cancer (22.7%), and leukemia (31.0%). Conclusions: We reported the most up-to-date 5-year cancer RS and NS in Zhejiang Province, China for the first time, and found that the 5-year survival for cancer patients in Zhejiang during 2018-2019 was relatively high. The population-based cancer registries are recognized as key policy tools that can be used to evaluate both the impact of cancer prevention strategies and the effectiveness of health systems.

A retrospective study: exploring the optimal patient population for adjuvant chemotherapy after D2 gastrectomy.

BACKGROUND: Adjuvant chemotherapy (CT) constitutes the primary approach for treating resectable advanced gastric cancer (GC). However, the effectiveness of postoperative CT can differ across various patient groups. This retrospective study aimed to examine how variances in clinical and pathologic factors affect postoperative CT. METHODS: This study enrolled 2060 patients with GC who underwent curative gastrectomy at Zhejiang Cancer Hospital between January 2008 and December 2017, with 1277 receiving postoperative CT. This study used Kaplan-Meier to determine the effect of clinical and pathology factors on CT benefits. In addition, univariate and multivariate Cox regression analyses were used to identify independent prognosis risk factors. RESULTS: Both univariate and multivariate analyses demonstrated that the absence of postoperative CT is an independent factor associated with a poor prognosis in patients with GC. The Kaplan-Meier univariate analysis revealed that specific subgroups, including males, those with a normal body mass index (BMI), the elderly, individuals with gastric adenocarcinoma, cases of nerve invasion by the tumor, vascular invasion by the tumor, tumor size ≥ 5 cm, and Tumor, Node, Metastasis (TNM) stage III, exhibited improved treatment outcomes with the administration of postoperative CT. The creation of nomograms using Cox regression and the rms package holds significant clinical relevance. CONCLUSION: Postoperative CT is advantageous for prolonging the survival of advanced patients undergoing D2 gastrectomy, particularly in male patients, the elderly, individuals with a normal BMI score, those diagnosed with gastric adenocarcinoma, cases, in which the tumor invades nerves or blood vessels, patients with a tumor size of ≥5 cm, and those with a TNM stage of III, as it results in improved treatment outcomes within these subgroups.

Safety and efficacy of a programmed cell death 1 inhibitor combined with oxaliplatin plus S-1 in patients with Borrmann large type III and IV gastric cancers.

BACKGROUND: Gastric cancer (GC) is the fifth most common and the fourth most lethal malignant tumour in the world. Most patients are already in the advanced stage when they are diagnosed, which also leads to poor overall survival. The effect of postoperative adjuvant chemotherapy for advanced GC is unsatisfactory with a high rate of distant metastasis and local recurrence. AIM: To investigate the safety and efficacy of a programmed cell death 1 (PD-1) inhibitor combined with oxaliplatin and S-1 (SOX) in the treatment of Borrmann large type III and IV GCs. METHODS: A retrospective analysis (IRB-2022-371) was performed on 89 patients with Borrmann large type III and IV GCs who received neoadjuvant therapy (NAT) from January 2020 to December 2021. According to the different neoadjuvant treatment regimens, the patients were divided into the SOX group (61 patients) and the PD-1 + SOX (P-SOX) group (28 patients). RESULTS: The pathological response (tumor regression grade 0/1) in the P-SOX group was significantly higher than that in the SOX group (42.86% vs 18.03%, P = 0.013). The incidence of ypN0 in the P-SOX group was higher than that in the SOX group (39.29% vs 19.67%, P = 0.05). The use of PD-1 inhibitors was an independent factor affecting tumor regression grade. Meanwhile, the use of PD-1 did not increase postoperative complications or the adverse effects of NAT. CONCLUSION: A PD-1 inhibitor combined with SOX could significantly improve the rate of tumour regression during NAT for patients with Borrmann large type III and IV GCs.

The role of reactive oxygen species in gastric cancer.

Gastric cancer (GC) ranks fifth in cancer incidence and fourth in cancer-related mortality worldwide. Reactive oxygen species (ROS) are highly oxidative oxygen-derived products that have crucial roles in cell signaling regulation and maintaining internal balance. ROS are closely associated with the occurrence, development, and treatment of GC. This review summarizes recent findings on the sources of ROS and the bidirectional regulatory effects on GC and discusses various treatment modalities for GC that are related to ROS induction. In addition, the regulation of ROS by natural small molecule compounds with the highest potential for development and applications in anti-GC research is summarized. The aim of the review is to accelerate the clinical application of modulating ROS levels as a therapeutic strategy for GC.

Oral microbiota and gastric cancer: recent highlights and knowledge gaps.

Gastric cancer is one of the most common malignant tumors worldwide and has a high mortality rate. However, tests for the early screening and diagnosis of gastric cancer are limited and invasive. Certain oral microorganisms are over-expressed in gastric cancer, but there is heterogeneity among different studies. Notably, each oral ecological niche harbors specific microorganisms. Among them, tongue coating, saliva, and dental plaque are important and unique ecological niches in the oral cavity. The colonization environment in different oral niches may be a source of heterogeneity. In this paper, we systematically discuss the latest developments in the field of the oral microbiota and gastric cancer and elucidate the enrichment of microorganisms in the oral ecological niches of the tongue coatings, saliva, and dental plaque in gastric cancer patients. The various potential mechanisms by which the oral microbiota induces gastric cancer (activation of an excessive inflammatory response; promotion of proliferation, migration, invasion, and metastasis; and secretion of carcinogens, leading to imbalance in gastric microbial communities) are explored. In this paper, we also highlight the applications of the rapeutics targeting the oral microbiota in gastric cancer and suggests future research directions related to the relationship between the oral microbiota and gastric cancer.

In-depth metaproteomics analysis of tongue coating for gastric cancer: a multicenter diagnostic research study.

BACKGROUND: Our previous study revealed marked differences in tongue images between individuals with gastric cancer and those without gastric cancer. However, the biological mechanism of tongue images as a disease indicator remains unclear. Tongue coating, a major factor in tongue appearance, is the visible layer on the tongue dorsum that provides a vital environment for oral microorganisms. While oral microorganisms are associated with gastric and intestinal diseases, the comprehensive function profiles of oral microbiota remain incompletely understood. Metaproteomics has unique strength in revealing functional profiles of microbiota that aid in comprehending the mechanism behind specific tongue coating formation and its role as an indicator of gastric cancer. METHODS: We employed pressure cycling technology and data-independent acquisition (PCT-DIA) mass spectrometry to extract and identify tongue-coating proteins from 180 gastric cancer patients and 185 non-gastric cancer patients across 5 independent research centers in China. Additionally, we investigated the temporal stability of tongue-coating proteins based on a time-series cohort. Finally, we constructed a machine learning model using the stochastic gradient boosting algorithm to identify individuals at high risk of gastric cancer based on tongue-coating microbial proteins. RESULTS: We measured 1432 human-derived proteins and 13,780 microbial proteins from 345 tongue-coating samples. The abundance of tongue-coating proteins exhibited high temporal stability within an individual. Notably, we observed the downregulation of human keratins KRT2 and KRT9 on the tongue surface, as well as the downregulation of ABC transporter COG1136 in microbiota, in gastric cancer patients. This suggests a decline in the defense capacity of the lingual mucosa. Finally, we established a machine learning model that employs 50 microbial proteins of tongue coating to identify individuals at a high risk of gastric cancer, achieving an area under the curve (AUC) of 0.91 in the independent validation cohort. CONCLUSIONS: We characterized the alterations in tongue-coating proteins among gastric cancer patients and constructed a gastric cancer screening model based on microbial-derived tongue-coating proteins. Tongue-coating proteins are shown as a promising indicator for identifying high-risk groups for gastric cancer. Video Abstract.

Burdens of stomach and esophageal cancer from 1990 to 2019 and projection to 2030 in China: Findings from the 2019 Global Burden of Disease Study.

Background: Stomach and esophageal cancer exhibit high morbidity and mortality rate in China, resulting in substantial disease burdens. It is imperative to identify the temporal trends of stomach and esophageal cancer from 1990 to 2019 and project future trends until 2030, which can provide valuable information for planning effective management and prevention strategies. Methods: We collected and analysed data from the Global Burden of Disease (GBD) between 1990 and 2019, including incidence, mortality, disability-adjusted life years (DALYs), age-standardised incidence rate (ASIR), mortality rate (ASMR) and DALYs rate. We also calculated and reported the proportion of mortality and DALYs attributable to risk factors by sex in China and different regions. The Bayesian age-period-cohort model was applied to project future trends until 2030. Results: The new cases, deaths and DALYs of stomach and esophageal cancer increased from 1990 to 2019. However, the ASIR, ASMR and age-standardised DALYs rates for stomach and esophageal cancer all decreased during the same period. These changes may be related to risks, such as smoking and diet. Furthermore, we utilised the projection model to estimate that the ASIR and ASMR of stomach and esophageal cancer among females will likely follow steady downward trends, while the ASMR of stomach cancer among males is expected to exhibit a significant decline. However, the ASIR of stomach and esophageal cancer and the ASMR of esophageal cancer among males are projected to display slight upward trends until 2030. Conclusions: The analysis of stomach and esophageal cancer trends in China from 1990 to 2030 reveals a general decline. However, it is crucial to acknowledge the persistent high burden of both cancers in the country. Adopting healthy lifestyle practices, including the reduction of tobacco and alcohol intake, avoidance of moldy foods and increased consumption of fresh fruits and vegetables can contribute to mitigating the risk of stomach and esophageal cancer. Significantly, the formulation and implementation of well-founded and efficacious public health policies are imperative for alleviating the disease burden in China.

Synthesis and evaluation of WK-X-34 derivatives as P-glycoprotein (P-gp/ABCB1) inhibitors for reversing multidrug resistance.

The emergence of multidrug resistance (MDR) in malignant tumors is one of the leading threats encountered currently by many chemotherapeutic agents. A proposed strategy to overcome MDR is to disable the efflux function of P-glycoprotein (P-gp/ABCB1), a critical member of the ABC transporter family that significantly increases the efflux of various anticancer drugs from tumor cells. In this study, structural modification of a third-generation P-gp inhibitor WK-X-34 based on bioisosteric and fragment-growing strategies led to the discovery of the adamantane derivative PID-9, which exhibited the best MDR reversal activity (IC50 = 0.1338 µM, RF = 78.6) in this series, exceeding those of the reported P-gp inhibitors verapamil and WK-X-34. In addition, compared with WK-X-34, PID-9 showed decreased toxicity to cells. Furthermore, the mechanism studies revealed that the reversal activity of adamantane derivatives PID-5, PID-7, and PID-9 stemmed from the inhibition of P-gp efflux. These results indicated that compound PID-9 is the most effective P-gp inhibitor among them with low toxicity and high MDR reversal activity, which provided a fundamental structural reference for further discovery of novel, effective, and non-toxic P-gp inhibitors.

Development and validation of a nomogram for predicting lymph node metastasis in early gastric cancer.

BACKGROUND: Lymph node metastasis (LNM) significantly impacts the treatment and prognosis of early gastric cancer (EGC). Consequently, the precise prediction of LNM risk in EGC patients is essential to guide the selection of appropriate surgical approaches in clinical settings. AIM: To develop a novel nomogram risk model for predicting LNM in EGC patients, utilizing preoperative clinicopathological data. METHODS: Univariate and multivariate logistic regression analyses were performed to examine the correlation between clinicopathological factors and LNM in EGC patients. Additionally, univariate Kaplan-Meier and multivariate Cox regression analyses were used to assess the influence of clinical factors on EGC prognosis. A predictive model in the form of a nomogram was developed, and its discrimination ability and calibration were also assessed. RESULTS: The incidence of LNM in the study cohort was 19.6%. Multivariate logistic regression identified tumor size, location, degree of differentiation, and pathological type as independent risk factors for LNM in EGC patients. Both tumor pathological type and LNM independently affected the prognosis of EGC. The model's performance was reflected by an area under the curve of 0.750 [95% confidence interval (CI): 0.701-0.789] for the training group and 0.763 (95%CI: 0.687-0.838) for the validation group. CONCLUSION: A clinical prediction model was constructed (using tumor size, low differentiation, location in the middle-lower region, and signet ring cell carcinoma), with its score being a significant prognosis indicator.

The promise and challenges of combination therapies with antibody-drug conjugates in solid tumors.

Antibody-drug conjugates (ADCs) represent an important class of cancer therapies that have revolutionized the treatment paradigm of solid tumors. To date, many ongoing studies of ADC combinations with a variety of anticancer drugs, encompassing chemotherapy, molecularly targeted agents, and immunotherapy, are being rigorously conducted in both preclinical studies and clinical trial settings. Nevertheless, combination therapy does not always guarantee a synergistic or additive effect and may entail overlapping toxicity risks. Therefore, understanding the current status and underlying mechanisms of ADC combination therapy is urgently required. This comprehensive review analyzes existing evidence concerning the additive or synergistic effect of ADCs with other classes of oncology medicines. Here, we discuss the biological mechanisms of different ADC combination therapy strategies, provide prominent examples, and assess their benefits and challenges. Finally, we discuss future opportunities for ADC combination therapy in clinical practice.

Spatiotemporal Quantification of HER2-targeting Antibody-Drug Conjugate Bystander Activity and Enhancement of Solid Tumor Penetration.

PURPOSE: Antibody-drug conjugate (ADC) has had a transformative effect on the treatment of many solid tumors, yet it remains unclear how ADCs exert bystander activity in the tumor microenvironment. EXPERIMENTAL DESIGN: Here, we directly visualized and spatiotemporally quantified the intratumor biodistribution and pharmacokinetics of different ADC components by developing dual-labeled fluorescent probes. RESULTS: Mechanistically, we found that tumor penetration of ADCs is distinctly affected by their ability to breach the binding site barrier (BSB) in perivascular regions of tumor vasculature, and bystander activity of ADC can only partially breach BSB. Furthermore, bystander activity of ADCs can work in synergy with coadministration of their parental antibodies, leading to fully bypassing BSBs and enhancing tumor penetration via a two-step process. CONCLUSIONS: These promising preclinical data allowed us to initiate a phase I/II clinical study of coadministration of RC48 and trastuzumab in patients with malignant stomach cancer to further evaluate this treatment strategy in humans.

Mutation characteristics and molecular evolution of ovarian metastasis from gastric cancer and potential biomarkers for paclitaxel treatment.

Ovarian metastasis is one of the major causes of treatment failure in patients with gastric cancer (GC). However, the genomic characteristics of ovarian metastasis in GC remain poorly understood. In this study, we enroll 74 GC patients with ovarian metastasis, with 64 having matched primary and metastatic samples. Here, we show a characterization of the mutation landscape of this disease, alongside an investigation into the molecular heterogeneity and pathway mutation enrichments between synchronous and metachronous metastasis. We classify patients into distinct clonal evolution patterns based on the distribution of mutations in paired samples. Notably, the parallel evolution group exhibits the most favorable prognosis. Additionally, by analyzing the differential response to chemotherapy, we identify potential biomarkers, including SALL4, CCDC105, and CLDN18, for predicting the efficacy of paclitaxel treatment. Furthermore, we validate that CLDN18 fusion mutations improve tumor response to paclitaxel treatment in GC with ovarian metastasis in vitro and vivo.