Glioblastoma (GBM) is the most common primary malignant intracranial tumor with a poor prognosis. Ferroptosis is a newly discovered, iron-dependent, regulated cell death, and recent studies suggest its close correlation to GBM. The transcriptome and clinical data were obtained for patients diagnosed with GBM from TCGA, GEO, and CGGA. Ferroptosis-related genes were identified, and a risk score model was constructed using Lasso regression analyses. Survival was evaluated by univariate or multivariate Cox regressions and Kaplan–Meier analyses, and further analyses were performed between the high- and low-risk groups. There were 45 ferroptosis-related different expressed genes between GBM and normal brain tissues. The prognostic risk score model was based on four favorable genes, CRYAB, ZEB1, ATP5MC3, and NCOA4, and four unfavorable genes, ALOX5, CHAC1, STEAP3, and MT1G. A significant difference in OS between high- and low-risk groups was observed in both the training cohort (p < 0.001) and the validation cohorts (p = 0.029 and 0.037). Enrichment analysis of pathways and immune cells and functioning was conducted between the two risk groups. A novel prognostic model for GBM patients was developed based on eight ferroptosis-related genes, suggesting a potential prediction effect of the risk score model in GBM.

Aim: As the second most prevalent subtype of epithelial ovarian cancers, ovarian clear cell carcinoma (OCCC) is known for its chemoresistance to conventional platinum‐based therapy. In this work, we examined the tryptophan (Trp) metabolism enzymes' differential expression in patients with OCCC to assess the potential for personalised treatment.Methods: A total of 127 OCCC tissues were used to construct tissue microarrays, and immunohistochemistry (IHC) staining of the Trp enzymes IDO1, IDO2, TDO2 and IL4I1 was performed. The correlations between Trp enzyme expression and clinical characteristics were analysed.Results: Positive IDO1, IDO2, TDO2 and IL4I1 staining was identified in 26.8%, 94.5%, 75.6% and 82.7% of OCCC respectively. IDO1‐positive samples were more common in the chemoresistant group than in the platinum‐sensitive group (46.7% vs. 19.8%). Moreover, positive expression of IDO1, TDO2 and IL4I1 was related to advanced stage, metastasis, bilateral tumours, endometriosis and tumour rupture (p < 0.05) respectively. Univariate analysis revealed a significant association between bilateral tumours, lymph node metastasis, advanced stage, distant metastasis and aberrant cytology with a poor prognosis for OCCC, while the absence of residual tumour was correlated with a favourable outcome (p < 0.05). However, only bilateral tumours and lymph node metastases were related to a poor prognosis after multivariate analysis.Conclusion: This is the first study to investigate the expression of the Trp enzymes IDO1, IDO2, TDO2 and IL4I1 in OCCC tissues. IDO2, TDO2 and IL4I1 were detected in the majority of OCCC. Clinical traits were correlated with IDO1, IDO2, TDO2 and IL4I1 expression. IDO1 may be used as a therapeutic target given the large percentage of chemoresistant cases with IDO1 expression. These results will aid the development of personalised therapies for OCCC.

Background: Ovarian clear cell carcinoma (OCCC), well known for its chemoresistance to platinum-based chemotherapy, exhibited a good response in clinical trials of anti–PD-1/PD-L1 inhibitors. By assessing PD-L1 expression, we sought to determine the potential therapeutic benefit of PD-1/PD-L1 inhibitors in OCCC. Methods and results: The retrospective study included 152 individuals with OCCC between 2019 and 2022 at Peking Union Medical College Hospital. Paired tumors of primary versus recurrent lesions (17 pairs from 15 patients) or primary versus metastatic lesions (11 pairs from 9 patients) were also included. The 22C3 pharmDx assay and whole sections were used for PD-L1 immunohistochemical staining. Pathologists with experience in premarket clinical trials evaluated PD-L1 expression based on various diagnostic criteria (TPS 1%, CPS 1, or CPS 10). The number and percentage of positive PD-L1 cases were 34 (22.4%, TPS ≥ 1%) and 59 (38.8%, CPS ≥ 1), respectively. Thirty-three (21.7%) of the cases had high PD-L1 expression (CPS ≥ 10). Half of the platinum-resistant patients (11/22) were PD-L1 positive (CPS ≥ 1). In addition, positive PD-L1 expression (CPS ≥ 1) was related to clinicopathological characteristics that represented a worse prognosis, such as advanced stages, lymph node metastasis, and distant metastasis (p = 0.032, p < 0.001 and p = 0.003, separately). PD-L1 was expressed equally or more in the recurrent lesion compared with its matched primary lesion. Conclusions: In conclusion, anti–PD-1/PD-L1 inhibitors are a promising therapeutic choice for OCCC. For evaluation of PD-L1 expression, CPS is more recommended than TPS. Evaluation of recurrent lesion was still suitable and predictive when the primary tumor tissue was not available. Distant metastatic lesions can serve as alternative samples for PD-L1 evaluation, while usage of lymphatic metastatic lesions is not recommended.

Background: For precise and reliable gene expression analysis, the acquisition of high-quality RNA is contingent upon excellent tissue preparation and handling. The optimal method for preserving tissues after surgical resection remains challenging due to the delays in delivery or the absence of cold storage equipment. Although RNAlater has been extensively adopted for tissue preservation, few studies have systematically evaluated the effects of various tissue preservation solutions and post-collection intervals on RNA integrity across a range of tissue types. Methods: Ten types of mouse tissues, representing common tissue species in biobanks, were collected after resection. Tissues were either flash-frozen in liquid nitrogen as controls or immersed in one of three RNA preservatives—TRIzol and two commercial RNAlater solutions—and stored at room temperature (RT) for 0, 4, or 8 h before being frozen. Total RNA was extracted using TRIzol method, and its integrity was assessed using the RNA Integrity Number (RIN). Results: The results indicated that both the post-collection interval and the type of RNA preservative significantly impact RNA integrity. Pancreatic tissue showed the poorest RNA integrity (RIN < 5.5), whereas heart and ovary tissue yielded high-quality RNA (RIN > 7) even without any preservatives after 8 h at RT. To maintain baseline RNA integrity (RIN > 5.5), tissues including brain, kidney, muscle, liver, intestine, and uterus should be immersed in preservative and frozen within 8 h. For lung tissue preserved in RNAlater, the maximum recommended time at RT was 4 h. Conclusions: Robust, high-quality RNA can be obtained from most mouse tissues stored in RNA preservatives for up to 8 h at RT, with only minor variations observed across the different preservatives tested.