Introduction

Drug resistance is a major challenge in cancer treatment. Developing new therapeutic strategies targeting mechanisms that enable cancer cells to evade conventional therapy is a priority. In this regard, regulated necrosis or necroptosis may be used to target apoptosis-resistant cancer cells. In turn, metal-based drugs have been used as chemotherapeutic agents, although the mechanism of action is still poorly understood.

Aims & Methods

Here, we studied a family of newly synthetized ruthenium (II)-triazene hybrids (Ru-TRZ) for their ability to induce apoptotic and/or necroptotic cell death. Human colorectal and hepatocellular carcinoma cell lines HT29 and HepG2, respectively, and murine AML12 immortalized hepatocytes and L929 fibrosarcoma cells were incubated with Ru-TRZ alone or in apoptosis blocking conditions. Cell death and viability were assessed by adenylate kinase (AK) release and MTS metabolism. Necroptosis was evaluated by immunoblot analysis of RIPK1, RIPK3 and MLKL, while apoptosis was assessed by caspase -3/7 activity. ROS production and mitochondrial membrane depolarization were used to evaluate mitochondrial dysfunction. To further confirm the role of necroptosis in Ru-TRZ-induced cell death, we used Ripk3 knockout cells or cells transiently transfected with Mlkl siRNA, and co-incubation with the necroptosis chemical inhibitor necrostatin-1 (Nec-1). Finally, the combinatory effect of Ru-TRZ and commonly used chemotherapeutic drugs was determined using CompuSyn software.

Results

Our results demonstrate that Ru-TRZ naturally induce apoptotic cell death. However, under apoptosis blocking conditions, treatment with these metal compounds was still highly cytotoxic for all cell lines tested, particularly cancer cells. Importantly, this effect was reverted by co-incubation with Nec-1 or after Mlkl post-transcriptional silencing, which implicates necroptosis as the death mechanism. Treatment with Ru-TRZ further increased the expression and activation of necroptosis mediators RIPK3 and MLKL, mitochondrial ROS production and induced mitochondrial membrane depolarization. Moreover, ablation of Ripk3 protected hepatocytes from Ru-TRZ-induced cytotoxicity and mitochondrial deleterious effects. Finally, Ru-TRZ have shown to potentiate synergistically the cytotoxic effects of commonly used chemotherapeutic drugs, such as 5- fluorouracil or oxaliplatin.

Conclusion

In conclusion, this family of Ru-TRZ shows potential as future anticancer agents, considering their ability to trigger necroptosis, in addition to apoptosis. This dual cell death approach is especially relevant in situations where apoptosis is compromised. Further, Ru-TRZ may be used in combination with conventional drugs to enhance cancer treatment effectiveness.

References

1. Chao, A. H. et al. Necroptosis Induced by Ruthenium(II) Complexes as Dual Catalytic Inhibitors of Topoisomerase I/II. Angew. Chemie 59, 16631–16637 (2020).
2. Chu, Q., Gu, X., Zheng, Q., Wang, J. & Zhu, H. Mitochondrial Mechanisms of Apoptosis and Necroptosis in Liver Diseases. Anal. Cell. Pathol. 2021, (2021).
3. Marshall, K. D. & Baines, C. P. Necroptosis : is there a role for mitochondria? Front. Physiol. 5, 1–5 (2014).

Introduction

Helicobacter pylori (HP) infection is the most significant environmental factor contributing to gastric carcinogenesis. However, the rising prevalence of antibiotic resistance in HP has become a global concern. Currently, there is limited research on the correlation between HP antibiotic resistance and early gastric cancer (EGC). This study aimed to detect HP resistance genes in EGC patients using qRT-PCR on paraffin-embedded ESD specimens and explore the association between HP resistance and EGC.

Aims & Methods

A total of 150 EGC patients who underwent endoscopic submucosal dissection (ESD) between January 1, 2023, and December 31, 2024, were enrolled. HP resistance genes were detected in post-ESD gastric mucosal paraffin sections. Resistance rates to various antibiotics were compared, and correlations between resistance and clinicopathological features were analyzed.

Results

Among the 150 EGC patients, 28 (18.67%) were HP-positive, with 18 (64.3%, 95% CI: 44.1%–81.4%) showing antibiotic resistance. Levofloxacin had the highest resistance rate (50.0%), followed by clarithromycin (38.9%), tetracycline (11.1%), and amoxicillin (5.6%). No resistance to furazolidone was observed. Multidrug resistance analysis revealed common combinations, including clarithromycin + quinolone (22.2%) and clarithromycin + quinolone + tetracycline (5.6%). No significant correlations were found between resistance and clinicopathological features such as tumor location, size, histologic type, differentiation, depth of invasion, or mucosal status (all *p* > 0.05).

Conclusion

HP antibiotic resistance is prevalent in EGC patients, with high resistance rates to levofloxacin and clarithromycin. However, no significant association was observed between HP resistance and clinicopathological characteristics of EGC. Further studies are needed to elucidate the role of resistant HP strains in gastric carcinogenesis.

References

[1]Yang L, Kartsonaki C, Yao P, de Martel C, Plummer M, Chapman D, Guo Y, Clark S, Walters RG, Chen Y, Pei P, Lv J, Yu C, Jeske R, Waterboer T, Clifford GM, Franceschi S, Peto R, Hill M, Li L, Millwood IY, Chen Z; China Kadoorie Biobank Collaborative Group. The relative and attributable risks of cardia and non-cardia gastric cancer associated with Helicobacter pylori infection in China: a case-cohort study. Lancet Public Health. 2021 Dec;6(12):e888-e896. doi: 10.1016/S2468-2667(21)00164-X.
[2]Lee YC, Chiang TH, Chou CK, Tu YK, Liao WC, Wu MS, Graham DY. Association Between Helicobacter pylori Eradication and Gastric Cancer Incidence: A Systematic Review and Meta-analysis. Gastroenterology. 2016 May;150(5):1113-1124.e5. doi: 10.1053/j.gastro.2016.01.028. Epub 2016 Feb 2.
[3]Dingsdag SA, Hunter N. Metronidazole: an update on metabolism, structure-cytotoxicity and resistance mechanisms. J Antimicrob Chemother. 2018 Feb 1;73(2):265-279. doi: 10.1093/jac/dkx351.
[4]Dingsdag SA, Hunter N. Metronidazole: an update on metabolism, structure-cytotoxicity and resistance mechanisms. J Antimicrob Chemother. 2018 Feb 1;73(2):265-279. doi: 10.1093/jac/dkx351.
[5]Lee SM, Kim N, Kwon YH, Nam RH, Kim JM, Park JY, Lee YS, Lee DH. rdxA, frxA, and efflux pump in metronidazole-resistant Helicobacter pylori: Their relation to clinical outcomes. J Gastroenterol Hepatol. 2018 Mar;33(3):681-688. doi: 10.1111/jgh.13906.

Introduction

Emerging experimental and clinical data suggest that the gut microbiome can significantly influence the antitumor efficacy of key chemotherapy agents, including 5-fluorouracil, oxaliplatin, and docetaxel. These agents form the backbone of the neoadjuvant chemotherapy (NAC) regimen, FLOT, which is widely used for the treatment of locally advanced gastric cancer (GC). However, despite growing evidence from preclinical models, clinical studies investigating the direct association between gut microbiome composition and the response to NAC in GC patients remain scarce.

Aims & Methods

This study aims to address this gap in knowledge by exploring the relationship between the gut microbiome and therapeutic outcomes in this clinical context. In this longitudinal observational study, we explored the association between pre-treatment fecal microbiome composition analyzed via 16S rRNA gene sequencing and histological tumor regression, as assessed by the Becker score, in GC patients undergoing NAC with the FLOT regimen, followed by gastrectomy.

Results

Among the 38 enrolled patients, 19 (50%) achieved a Becker score of 1–2 and were classified as ‘Responders,’ while the other 19 (50%) were classified as ‘Non-responders’. Responders exhibited a higher abundance of Parabacteroides distasonis, Alistipes sp. AL-1, and Bacteroides plebeius. A combined biomarker of these species demonstrated robust predictive accuracy for a favorable response to NAC, with sensitivity of 89%, specificity of 63%, and an AUC of 0.8 (95% CI: 0.66–0.94). In contrast, non-responders showed a predominance of bacterial genera, including Ruminococcaceae UCG-014, Ruminococcus 1, Ruminococcaceae UCG-005, and the [Eubacterium] eligens group. The combined biomarker of these genera demonstrated excellent predictive performance for poor NAC response, with sensitivity of 89%, specificity of 95%, and an AUC of 0.93 (95% CI: 0.85–1.0).

Conclusion

The results of our study support the hypothesis that the pre-treatment gut microbiome composition can serve as a reliable biomarker for predicting both positive and negative responses to NAC in GC patients. By identifying specific microbial signatures associated with chemotherapy outcomes, this research provides critical insights into how microbiome-based strategies might enhance personalized treatment regimens for GC. Future studies are needed to validate these findings and explore potential therapeutic interventions targeting the microbiome to improve clinical outcomes in GC patients.

Introduction

In Japan, the standard treatment for resectable locally advanced esophageal squamous cell cancer (ESCC) is neoadjuvant triplet chemotherapy (fluorouracil, cisplatin, and docetaxel [DCF]) followed by surgery, based on the results of the phase III randomized controlled study (JCOG1109). Some reports suggest that preoperative endoscopic evaluation of the primary tumor may predict postoperative outcomes. Given the increasing importance of endoscopic evaluation of response to neoadjuvant therapy in primary tumor, the 12th edition of the Japanese Classification of Esophageal Cancer introduced a new endoscopic sub-classification “RR (Remarkable Response)”, which was defined as showing remarkably shrink to nearly T1 depth after treatment. However, its clinical significance remains unclear.

Aims & Methods

The aim of this study is to determine the clinical significance of a new endoscopic sub-classification “RR” by evaluating its association with both histological response in surgical specimens and postoperative prognosis. We retrospectively analyzed the patients with resectable locally advanced ESCC (cT2-3/N0-3/M0-1, UICC-TNM 8th edition) who were performed with ≥1 cycle of neoadjuvant DCF therapy followed by surgery at our institution between April 2015 and March 2020. Exclusion criteria were: 1) JCOG1109 participants, 2) not evaluated the primary lesion by endoscopy before or after DCF therapy due to esophageal stricture, 3) >56 days from DCF therapy completion to surgery, or 4) pathologically non-curative resection (R1-2). Two endoscopists retrospectively evaluated pre- and post-DCF therapy endoscopic images with masked prognostic information and classified the cases into three groups: 1) RR, 2) non-RR and 3) PD (Progressive disease). Histological response data were retrospectively collected from medical records. According to the 12th edition of the Japanese Classification of Esophageal Cancer, all surgically resected specimens containing visible primary tumor tissue underwent histological examination in cases where preoperative treatment has been administered. Histological response was graded according to the Japanese Classification of Esophageal Cancer, on a four-point scale ranging from grade 0 (ineffective) to grade 1 (slightly effective), grade 2 (moderately effective), and grade 3 (markedly effective). We evaluated the proportions of cases achieving histological response of grade 2-3 in each group, and also calculated 3-year RFS and OS rates in each group.

Results

Of 114 eligible patients (median age 66.5 years [range 42-76], 91 males), clinical stage distribution was IIB/IIIA/IIIB/IVA/IVB: 1/0/58/15/40. 97/0/17 patients received 3/2/1 cycles of neoadjuvant DCF therapy. By endoscopic evaluation, 63 patients were classified as RR, 51 as non-RR, and 0 as PD. Among RR cases, 45 patients (71.4%) showed histological response of grade 2-3, while among non-RR cases, 5 patients (9.8%) showed grade 2-3. During the median follow-up of 42.6 months, 3-year RFS rates for RR/non-RR groups were 62.2%/49.0% (P=0.098), and 3-year OS rates were 76.9%/53.0% (P=0.026).

Conclusion

The newly introduced “RR (Remarkable Response)” of sub-classification for endoscopic evaluation after neoadjuvant chemotherapy may be useful for predicting histological response and stratifying prognosis in locally advanced ESCC.

Introduction

Gastric cancer with high morbidity and mortality afflicts a significant proportion of the worldwide population. Long non-coding RNAs (lncRNAs) play an important role in the development of gastric cancer and are closely associated with programmed cell death (PCD), which can be influenced by post-translational protein modifications.

Aims & Methods

Sequencing data of lncRNAs in patients with gastric cancer were obtained from TCGA and ARCG database. Important prognostic lncRNAs were identified through LASSO algorithm and Kaplan–Meier survival curve analysis and receiver operating characteristic curve analysis were used to evaluate the prognostic power of this model. Their effects on the biological functions of gastric cancer cells were investigated by in-vitro experiments, as well as the relationship between these lncRNAs and PCD, glycosylation.

Results

WGCNA and correlation analyses identified 168 PCD and glycosylation-related lncRNAs, 36 of which were of differential expression and prognostic value by univariate Cox analysis. A 11-lncRNA signature including MIR4435-2HG, LINC02381, LINC00106, LSAMP-AS1, LINC01140, LINC01614, RPH3AL-AS1, LINC02864, LEF1-AS1, LINC00844 and DPH6-DT was established and showed good performance in both TCGA and ARCG set. Differences in immune cells, immune functions and gene mutation were also found between high-risk and low-risk groups. In vitro experiments showed that PCD and glycosylation were influenced by RPH3AL-AS1 and LINC00106 knockdown.

Conclusion

This PCD and glycosylation-related signature may be a promising biomarker for predicting clinical outcomes in patients with gastric cancer.

References

Zhuo W, Liu Y, Li S, Guo D, Sun Q, Jin J, et al. Long Noncoding RNA GMAN, Up-regulated in Gastric Cancer Tissues, Is Associated With Metastasis in Patients and Promotes Translation of Ephrin A1 by Competitively Binding GMAN-AS. Gastroenterology. 2019;156(3):676-91.e11.
Zhang E, He X, Zhang C, Su J, Lu X, Si X, et al. A novel long noncoding RNA HOXC-AS3 mediates tumorigenesis of gastric cancer by binding to YBX1. Genome Biol. 2018;19(1):154.
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Chen Y, Jia K, Sun Y, Zhang C, Li Y, Zhang L, et al. Predicting response to immunotherapy in gastric cancer via multi-dimensional analyses of the tumour immune microenvironment. Nat Commun. 2022;13(1):4851.
Liu L, Li H, Hu D, Wang Y, Shao W, Zhong J, et al. Insights into N6-methyladenosine and programmed cell death in cancer. Mol Cancer. 2022;21(1):32.