Purpose: To compare the efficacy and safety of high-dose vitamin C plus FOLFOX ± bevacizumab versus FOLFOX ± bevacizumab as first-line treatment in patients with metastatic colorectal cancer (mCRC). Patients and Methods: Between 2017 and 2019, histologically confirmed patients with mCRC (n = 442) with normal glucose-6-phosphate dehydrogenase status and no prior treatment for metastatic disease were randomized (1:1) into a control (FOLFOX ± bevacizumab) and an experimental [high-dose vitamin C (1.5 g/kg/d, intravenously for 3 hours from D1 to D3) plus FOLFOX ± bevacizumab] group. Randomization was based on the primary tumor location and bevacizumab prescription. Results: The progression-free survival (PFS) of the experimental group was not superior to the control group [median PFS, 8.6 vs. 8.3 months; HR, 0.86; 95% confidence interval (CI), 0.70–1.05; P = 0.1]. The objective response rate (ORR) and overall survival (OS) of the experimental and control groups were similar (ORR, 44.3% vs. 42.1%; P = 0.9; median OS, 20.7 vs. 19.7 months; P = 0.7). Grade 3 or higher treatment-related adverse events occurred in 33.5% and 30.3% of patients in the experimental and control groups, respectively. In prespecified subgroup analyses, patients with RAS mutation had significantly longer PFS (median PFS, 9.2 vs. 7.8 months; HR, 0.67; 95% CI, 0.50–0.91; P = 0.01) with vitamin C added to chemotherapy than with chemotherapy only. Conclusions: High-dose vitamin C plus chemotherapy failed to show superior PFS compared with chemotherapy in patients with mCRC as first-line treatment but may be beneficial in patients with mCRC harboring RAS mutation.

Background: Gastric cancer (GC) is one of the most common malignancies in the world, and the fourth most frequent malignancy worldwide. YTHDF2 (YTH domain family 2, YTHDF2) binds to mRNA containing m6A, thereby regulating the localization and stability of the bound mRNA. YTHDF2 was shown to be associated with some cancer patient prognosis. However, the effect of YTHDF2 on gastric cancer and the molecular mechanism of this effect have not been documented.Methods: To conduct this research, YTHDF2 expression levels in public databases and gastric cancer patient samples were analyzed. The effects of YTHDF2 on the growth of gastric cancer cells were detectedin vivoandin vitro.RNA-seq was used to analyze the signal pathways regulated by YTHDF2, and experiments were carried out for verification.Results: In our study, we found that YTHDF2 has lower expression in GC tissues and GC cells, and inhibits the growth of GC cells. In addition, the analysis of clinical data found that the expression level of YTHDF2 is closely related to the stage of GC and the survival of patients with GC. RNA sequencing results showed that overexpression of YTHDF2 significantly reduced protein expression in the FOXC2 (Forkhead box protein C2, FOXC2) signaling pathway. Finally, we found that knockout of FOXC2 reversed the inhibitory effect of YTHDF2 on GC cells.Conclusion: In summary, YTHDF2 inhibits the growth of GC cells by negatively regulating FOXC2 and may serve as a prognostic marker in GC.

Background: Paired-like homeodomain transcription factor 1 (PITX1) participates in miscellaneous biological processes including cell growth, development, progression and invasion in various malignant tumors. However, the analysis of the association between PITX1 expression and the survival in breast cancer remains unclear. Methods: Clinical prognostic parameters and survival data related to PITX1 in breast cancer patients were performed using the bioinformatic analysis including Oncomine, Bc-GenExMiner v4.3, PrognoScan and UCSC Xena. Results: We found that PITX1 gene expression was significantly higher in different histological classification of breast cancer. The Scarff-Bloom-Richardson (SBR) grade, Nottingham prognostic index (NPI), estrogen receptor (ER) negative, epidermal growth factor receptor-2（HER2）positive，lymph node positive, triple-negative status and basal-like status were positively correlated with PITX1 level, except for patients’ age and the progesterone receptor (PR) status. We have found that the increased PITX1 expression correlated with worse relapse-free survival, disease specific survival and overall survival. PITX1 was positively correlated with metastatic relapse-free survival and distant metastasis-free survival. We also confirmed positive correlation between PITX1 and the nucleotide-binding oligomerization domain 2 (NOD2). Conclusion: The lower expression of PITX1 was associated with better clinical prognostic parameters and clinical survival in breast cancer according to the bioinformatic analysis.

B7-H3 is a type I membrane protein that has contradictory co-stimulatory and co-inhibitory effects in adaptive and anti-tumour immunity. B7-H3 is up-regulated in many malignant tumours, including breast cancer. Therefore, we hypothesise that B7-H3, which has an immunosuppressive role, suppresses anti-tumour immunity. The aim of this study was to clarify the role of B7-H3 in the tumor microenvironment in breast cancer, explore the possibility of B7-H3 as a target for clinical immunotherapy, and provide reference for clinical work. We knocked down B7-H3 with siRNA in MCF7 breast cancer cells, which we termed MCF7-B7-H3-KD cells, and the expression of B7-H3 was assessed by flow cytometry. GAPDH (glyceraldehyde-3-phosphate dehydrogenase) knockdown was used as a control (MCF7-Gapdh). MCF7-B7-H3-KD and MCF7-Gapdh cells were co-cultured with peripheral blood mononuclear cells (PBMCs) and CD3+ T cells from healthy donors to assess the effect of B7-H3 loss. PBMCs cultured with MCF7-Gapdh cells showed decreased activation, proliferation, and function of CD8+ T cells, but there was no effect on the proliferation of CD4+ T cells. However, when MCF7-B7-H3-KD cells were co-cultured with PBMCs, the proliferation ability of CD4+ T cells and CD8+ T cells was significantly higher than that observed in MCF7-Gapdh cell co-culture. Additionally, co-culture with MCF7-Gapdh cells decreased the expression of IFN-γ (Interferon-γ). However, after co-culture with MCF7-B7-H3-KD cells, there was an increase in IFN-γ. We further found that this inhibitory effect on IFN-γ was because of decreased mTOR (the mammalian target of rapamycin) phosphorylation in T cells. Treatment of T cells co-cultured with MCF7-B7-H3-KD cells with an mTOR inhibitor blocked the secretion of IFN-γ. B7-H3 on tumour cells inhibits the proliferation of CD4+ and CD8+ T cells and inhibits the release of IFN-γ by decreasing mTOR signalling. A better understanding of these complex immune regulatory mechanisms should facilitate the generation of more powerful and selective tools to manipulate cancer therapy.

Cadherin 17 (CDH17) is highly expressed in digestive system cancers, and the potential of nanobodies targeting CDH17 as imaging probes and delivery vehicles for radioactive β-particles warrants exploration for their theranostic potential in CDH17-overexpressing gastric cancer (GC). In this study, we screened an anti-CDH17 nanobody library and constructed two antibodies: anti-CDH17 VHH (recombinant nanobody fused with a polyhistidine tag) and anti-CDH17 VHH-ABD (recombinant nanobody fused with an albumin-binding domain). VHH targeting CDH17 and its derivative VHH-ABD were conjugated with DOTA and labeled with radionuclide ¹⁷⁷Lu. The pharmacokinetics and theranostic efficacy of these agents were evaluated in the GC xenograft models. [¹⁷⁷Lu]Lu-VHH and [¹⁷⁷Lu]Lu-VHH-ABD exhibited high radiochemical purity (>99%, n = 3) and successfully delineated CDH17-positive gastric cancer tissues on SPECT/CT imaging. Compared with the rapid renal clearance of [¹⁷⁷Lu]Lu-VHH, [¹⁷⁷Lu]Lu-VHH-ABD demonstrated prolonged circulation times with increased and sustained tumor accumulation. Survival experiments in the MKN-45 tumor model revealed that two doses of [¹⁷⁷Lu]Lu-VHH-ABD effectively suppressed tumor growth, with limited systemic biotoxicity. Histological analysis using hematoxylin and eosin (H&E) staining and Ki67 immunohistochemistry confirmed structural disruption and low tumor cell proliferative activity in the tumor tissue. In preclinical studies, [¹⁷⁷Lu]Lu-anti-CDH17 VHH-ABD demonstrated substantial antitumor efficacy with manageable toxicity, offering promising clinical potential as a viable therapeutic option for CDH17-overexpressing GC.