A single-cell atlas of conventional central chondrosarcoma reveals the role of endoplasmic reticulum stress in malignant transformation.

The transformation of benign lesions to malignant tumours is a crucial aspect of understanding chondrosarcomas, which are malignant cartilage tumours that could develop from benign chondroid lesions. However, the process of malignant transformation for chondroid lesions remains poorly understood, and no reliable markers are available to aid clinical decision-making. To address this issue, we conducted a study analysing 11 primary cartilage tumours and controls using single-cell RNA sequencing. By creating a single-cell atlas, we were able to identify the role of endoplasmic reticulum (ER) stress in the malignant transformation of conventional central chondrosarcomas (CCCS). Our research revealed that lower levels of ER stress promote chondrosarcoma growth in a patient-derived xenograft mouse model, while intensive ER stress reduces primary chondrosarcoma cell viability. Furthermore, we discovered that the NF-κB pathway alleviates ER stress-induced apoptosis during chondrosarcoma progression. Our single-cell signatures and large public data support the use of key ER stress regulators, such as DNA Damage Inducible Transcript 3 (DDIT3; also known as CHOP), as malignant markers for overall patient survival. Ultimately, our study highlights the significant role that ER stress plays in the malignant transformation of cartilaginous tumours and provides a valuable resource for future diagnostic markers and therapeutic strategies.

A 47-Year-Old Woman With Hemoptysis and a Lung Cyst.

CASE PRESENTATION: A 47-year-old woman was admitted to the hospital for an episode of hemoptysis. She coughed out small amount of clotted blood the morning of admission. She had no other symptoms on further review. Her medical history was unremarkable with the exception of an upper respiratory tract infection 9 months previously. She did not have any significant medical history or recent sick contacts. She was a lifelong nonsmoker and the mother of three teenaged children. She had irregular menses for the past 2 years, and her last menstrual period was 3 months ago. She reliably reported not engaging in any sexual contact for the past 2 years.