Background: Oncolytic virus M1 (OVM), a naturally occurring alphavirus, has demonstrated potent antitumor activity in various solid tumor models by inducing immunogenic cell death and activating CD8 ⁺ T cells. However, its in vivo efficacy varies widely, and resistance mechanisms remain poorly understood. Tumor-associated macrophages (TAMs), key immunosuppressive cells within the tumor microenvironment, may limit OVM therapeutic potential. Methods: We investigated the role of TAMs in OVM resistance using multiple syngeneic mouse tumor models (MC38 colorectal cancer, KPC1199 pancreatic cancer, RM1 prostate cancer, and B16F10 melanoma). TAMs were depleted using clodronate liposomes or CSF1R (Colony Stimulating Factor 1 Receptor) antibodies. Flow cytometry, mass cytometry, quantitative reverse transcription-PCR, and transcriptomic sequencing were employed to assess TAMs infiltration, viral load, and immune responses. CD8 ⁺ T cells were selectively depleted to determine their functional relevance. Results: TAMs infiltration was positively correlated with resistance to OVM across tumor models. Depletion of TAMs increased intratumoral viral load and promoted accumulation of GZMB ⁺ CD8 ⁺ T cells. RNA sequencing analysis revealed upregulation of antiviral and T-cell immune pathways in TAMs-depleted tumors. Importantly, the therapeutic benefit of TAMs depletion was abrogated on CD8 ⁺ T-cell depletion, confirming their essential role in mediating OVM efficacy. In both OVM non-responsive and responsive tumors, TAMs depletion enhanced OVM-mediated tumor suppression and survival. Conclusions: TAMs, particularly M1-like subsets, play a critical role in mediating resistance to OVM therapy by reducing viral persistence and suppressing CD8 ⁺ T-cell responses. Targeting TAMs significantly improves the antitumor efficacy of OVM in solid tumors. These findings support the development of TAMs-targeted combination strategies to optimize oncolytic virotherapy.

Proto-oncogenic receptor tyrosine kinase (KIT) ligand (KITL) secreted by granulosa cells and its receptor KIT on oocytes are crucial for primordial follicle formation and activation, and follicular development. In the present study, ZnSO₄ decreased the number of primordial and growing follicles in cultured neonatal mouse ovaries when KITL-KIT signaling was inhibited by ISCK03. ZnSO₄ also significantly increased the mRNA and protein levels of Zrt/Irt-like protein 6 (ZIP6, a zinc importer) and zinc levels in the oocytes of cultured neonatal mouse ovaries in the presence of ISCK03, suggesting that the increase in ZIP6 levels results in zinc overload in the oocytes of cultured neonatal mouse ovaries. Further experiments indicated that zinc overload resulted in oocyte apoptosis in cultured neonatal mouse ovaries via oxidative stress-driven dual mechanisms: irreversible DNA damage in the nucleus and autophagic flux blockade in the cytoplasm of oocytes. Moreover, the intraperitoneal injection of ZnSO₄ and ISCK03 significantly increased ZIP6 expression, DNA damage, autophagic flux blockade, and apoptosis of oocytes in neonatal mice. Taken together, these findings indicate that granulosa cell-secreted KITL is involved in maintaining zinc homeostasis in the oocytes of neonatal mouse ovaries. This study not only reveals a novel function of granulosa cells in supporting oocyte homeostasis, but also provides a theoretical basis for identifying individuals susceptible to zinc dyshomeostasis caused by the impaired KITL-KIT signaling.

Background: To compare the aneuploidy rate in spontaneous abortion chorionic villus (SA-CV) after D5 and D6 thawed-frozen blastocyst transfer(TBT). Methods: This retrospective cohort study recruited 522 patients with early spontaneous abortion from March 2012 to January 2020 in the our center. The aneuploidy rate of SA-CV was compared according to the blastocyst development stage: D5 group (n = 398) and D6 group (n = 124). Results: Patients’ characteristics, including age, body mass index, follicle-stimulating hormone, fertilization methods, type of infertility, infertility duration, and gestational age when abortion, did not differ between the two groups (all P > 0.05). Although the mean number of embryos was significantly higher in D6 than in the D5 group (P < 0.001), the mean number of high-quality embryos was similar (P = 0.773). In the D5 group, 46.5% of SA-CV showed aneuploidy, which was comparable to 41.1% in the D6 group (P = 0.296). After further grouping according to age (> 35 years or ≤ 35 years), the difference between the D5 and D6 groups remained not statistically significant (P = 0.247 and P = 0.690). Multivariate logistic analysis showed that women’s age was independently associated with the aneuploidy rate (OR = 0.891; 95% CI: [0.854–0.930]; P < 0.001). The rate of chromosomal aneuploidy was significantly higher in the age > 35 years group than in the age ≤ 35 years group (61.0% vs. 39.4%, P < 0.001). Other factors, including blastocyst formation speed, were not significant predictors of aneuploidy rate. Conclusions: The rate of chromosomal aneuploidy in SB-CV after D6 TBT was comparable to that after D5 TBT. Chromosomal aneuploidy may not be a main factor contributing to the high prevalence early pregnancy loss at D6 group.

Borderline ovarian tumors (BOTs) are neoplasms of low malignant potential that predominantly affect women of reproductive age. Fertility preservation through fertility-sparing surgery is widely practiced; however, concerns remain regarding the risk of tumor recurrence and the reproductive outcomes following in vitro fertilization (IVF). This study aimed to evaluate IVF/ intracytoplasmic sperm injection (ICSI) outcomes in BOTs patients post-FSS and to assess the association between ovarian stimulation parameters and tumor recurrence. In this retrospective cohort study conducted at Sixth Hospital of Sun Yat-sen University from May 2010 to May 2023, 65 women with a history of FSS for BOTs who underwent IVF/ICSI were identified. After propensity score matching, 61 BOTs patients were compared with 181 control patients without ovarian tumors. Key outcomes evaluated included ovarian stimulation parameters, live birth rates, neonatal outcomes and risk factors for tumor recurrence. The BOTs and control groups exhibited similar outcomes regarding the number of oocytes retrieved, the quality and number of embryos, and live birth rates from the first IVF/ICSI cycles. The cumulative live birth rate over 13 years and neonatal parameters (gestational age, birth weight, and body length) were also comparable between groups. Tumor recurrence was observed in 8.62% of BOTs patients, with no significant association identified between recurrence and ovarian stimulation parameters or peak estradiol levels. IVF/ICSI following fertility-sparing surgery for BOTs patients yields reproductive and neonatal outcomes comparable to those in patients without BOTs and does not increase the risk of tumor recurrence. These findings support the safety and efficacy of IVF as a fertility treatment option for BOTs patients after conservative surgery. Further prospective studies with larger cohorts are warranted to validate these results and refine ovarian stimulation strategies. Not applicable.

STUDY QUESTION: How does iron overload affect ovarian function in pediatric patients with transfusion-dependent beta-thalassemia major? SUMMARY ANSWER: Iron overload in pediatric patients with beta-thalassemia major is strongly associated with decreased ovarian reserve and mitochondrial damage. WHAT IS KNOWN ALREADY: Beta-thalassemia major is a severe blood disorder necessitating frequent blood transfusions, leading to iron overload. Excessive iron causes oxidative stress and damage in various organs, including the ovaries, but its impact on ovarian function in pediatric patients has not been fully explored. STUDY DESIGN, SIZE, DURATION: This study analyzed data from 194 pediatric patients who were treated at The Sixth Affiliated Hospital of Sun Yat-Sen University between January 2021 and January 2024, among whom 138 had beta-thalassemia major. Meanwhile, we conducted experiments using human samples and mouse models of iron overload. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study involved 194 pediatric patients. Clinical assessments measured serum ferritin and ovarian reserve indicators anti-Müllerian hormone (AMH) and antral follicle count. Ovarian tissue from pediatric patients was used for histopathological examination, immunohistochemical (IHC) staining, transmission electron microscopy (TEM), and transcriptome analysis, to investigate the effects of iron overload. For the animal experiments, we utilized 20 newborn female mice to establish an iron overload and control model. These animals underwent comprehensive evaluations, including histopathological examination, TEM, and IHC analyses, to systematically investigate the impact of iron overload on ovarian tissue. MAIN RESULTS AND THE ROLE OF CHANCE: Pubertal pediatric patients with high iron overload had significantly lower AMH, indicating reduced ovarian reserve, accompanied by evident mitochondrial damage and fibrotic remodeling in ovarian tissues, collectively contributing to impaired ovarian function. Decreased AMH and impaired follicular development were also observed in iron-overloaded mice, along with mitochondrial damage and ovarian fibrosis. LARGE SCALE DATA: Transcriptome data are available at China National Center for Bioinformation, reference HRA004373 and HRA013348. LIMITATIONS, REASONS FOR CAUTION: The cross-sectional design limits causality assessment. The sample size for molecular analyses is relatively small, necessitating larger, longitudinal studies to confirm these findings and understand long-term effects. WIDER IMPLICATIONS OF THE FINDINGS: Effective iron management in pediatric patients with beta-thalassemia major is crucial to preserving ovarian function and preventing long-term reproductive issues. These findings can guide clinical practices and therapeutic strategies to mitigate iron overload’s adverse effects on ovarian health. In this study, mitochondrial dysfunction may compromise cellular energy production and amplify tissue vulnerability to ischemia-reperfusion injury during transplantation. Additionally, fibrosis-induced structural rigidity may hinder revascularization of transplanted tissue, further reducing success rates. These findings underscore the need to monitor post-transplant survival rates. Further experimental investigations are warranted to explore this critical issue. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Key R&D Program of China (2022YFC2703000); National Natural Science Foundation of China (U24A20662, 82271651); Clinical Research Fund of Guangdong Medical Association (2025SZ-B1001); Postdoctoral Fellowship Program of CPSF (GZC20233216); and Guangdong Basic and Applied Basic Research Foundation (2023A1515110325). The authors declared no competing interests.

Fertility preservation is crucial for females facing gonadotoxic treatments. Controlled ovarian stimulation (COS) followed by oocyte cryopreservation is a well-established method, while ovarian tissue-derived oocyte in vitro maturation (OTO-IVM) is an emerging technique that can be used when COS is contraindicated or time is limited. However, OTO-IVM faces challenges such as low oocyte maturation rates and limited follow-up data. This study aimed to compare the clinical outcomes of COS oocyte cryopreservation and OTO-IVM, with a focus on the impact of transportation methods and the use of gonadotropin (Gn) before oophorectomy on OTO-IVM outcomes. This retrospective study analyzed data from 472 patients who underwent fertility preservation procedures at the Reproductive Medicine Research Center, The Sixth Affiliated Hospital, Sun Yat-sen University, from July 2012 to July 2024. Patients diagnosed with cancer or requiring gonadotoxic treatments were included. The study compared oocyte maturation, fertilization, and embryo transfer outcomes between COS and OTO-IVM groups. Statistical analyses were performed using Student’s t-test for continuous data and Chi-squared or Fisher’s exact test for categorical data, with significance defined as P < 0.05. COS group resulted in a significantly higher oocyte maturation rate (86.11%) compared to OTO-IVM group (39.43%). Direct oocyte transport yielded a higher rate of denuded oocytes compared to ovarian tissue transport. The use of Gn before oophorectomy in OTO-IVM significantly improved the IVM maturation rate (51.90% vs. 38.00%, P < 0.001). COS oocyte cryopreservation remains more effective than OTO-IVM. However, the study highlighted the importance of optimizing transportation methods and using Gn before oophorectomy to improve OTO-IVM outcomes. These findings could guide clinical practice in selecting appropriate fertility preservation strategies. Further research is needed to refine OTO-IVM techniques and enhance their clinical applicability.