Induction of lung lesions by bronchial administration using bronchoscope technique in mice.

This study aimed to establish an exposure method that can induce homogeneous lesions with minimal inter-individual variability. The distribution of lesions induced by bleomycin (BLM) administration was also analyzed. C57BL mice were intrabronchially administered 20 µL of BLM (3 mg/mL) using a bronchoscope in the left or right bronchus. The mice were sacrificed 14 days after administration, and their lungs were evaluated histopathologically. BLM-induced inflammatory lesions were widely observed in the lungs. In the left bronchus-treated group, lesions were uniformly observed throughout the lobe, and no individual differences were noted. Meanwhile, in the right bronchus-treated group, individual differences in the distribution of the pulmonary lesions were observed. The distribution of lesions differed among the four lobes of the right lung owing to their anatomical features. Administration into the left bronchus is recommended for highly homogeneous lung exposure and for establishing models that contribute to highly accurate toxicity and efficacy evaluations.

Parenchymatous glossitis: A case report.

We present a case of parenchymatous glossitis with unilateral severe inflammation of the hyoglossus muscle, resulting in laryngeal edema. The route of inflammation was unique. Contrast-enhanced CT was useful for diagnosis. Administration of sensitive antibiotics led to improvement. Creatine phosphokinase may be an indicator of diagnosis and treatment response.

Squamous cell papilloma of the hypopharynx with elongated villous projections.

Squamous cell papilloma with elongated villous projections may occur in the hypopharynx and present with symptoms observable on physical examination.

Changes in serum lactate dehydrogenase as a prognostic factor in patients with head and neck squamous cell carcinoma treated with immune checkpoint inhibitors.

BACKGROUND: Lactate dehydrogenase (LDH) is involved in the Warburg effect. Elevated serum LDH is a prognostic marker for metastatic solid cancer. AIM: To investigate the prognostic impact of serum LDH in patients with head and neck squamous cell carcinoma treated with immune checkpoint inhibitors (ICIs). MATERIALS AND METHODS: This retrospective study included 129 patients treated with ICIs between 2017 and 2023. The effects of pretreatment LDH, LDH at 3 months, and change in LDH during the first 3 months (ΔLDH) on overall survival (OS) and progression-free survival (PFS) were analyzed using the Kaplan-Meier method and Cox regression model. RESULTS: The 1-year PFS and OS rates for high and low groups were 6.0% and 30.1% for pretreatment LDH (p = 0.044), 25.7% and 38.3% for on-treatment LDH (p = 0.079), and 14.3% and 38.7% for ΔLDH (p = 0.008), as well as 42.1% and 60.9% for pretreatment LDH (p = 0.109), 56.0% and 80.5% (p < 0.001) for on-treatment LDH, and 31.0% and 81.0% for ΔLDH (p < 0.001), respectively. ΔLDH was an independent prognostic factor for both PFS and OS. CONCLUSIONS AND SIGNIFICANCE: ΔLDH can be used to predict ICI treatment outcomes and as a marker in deciding to continue ICI therapy.

PRMT1 Sustains De Novo Fatty Acid Synthesis by Methylating PHGDH to Drive Chemoresistance in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) chemoresistance hampers the ability to effectively treat patients. Identification of mechanisms driving chemoresistance can lead to strategies to improve treatment. Here, we revealed that protein arginine methyltransferase-1 (PRMT1) simultaneously methylates D-3-phosphoglycerate dehydrogenase (PHGDH), a critical enzyme in serine synthesis, and the glycolytic enzymes PFKFB3 and PKM2 in TNBC cells. 13C metabolic flux analyses showed that PRMT1-dependent methylation of these three enzymes diverts glucose toward intermediates in the serine-synthesizing and serine/glycine cleavage pathways, thereby accelerating the production of methyl donors in TNBC cells. Mechanistically, PRMT1-dependent methylation of PHGDH at R54 or R20 activated its enzymatic activity by stabilizing 3-phosphoglycerate binding and suppressing polyubiquitination. PRMT1-mediated PHGDH methylation drove chemoresistance independently of glutathione synthesis. Rather, activation of the serine synthesis pathway supplied α-ketoglutarate and citrate to increase palmitate levels through activation of fatty acid synthase (FASN). Increased palmitate induced protein S-palmitoylation of PHGDH and FASN to further enhance fatty acid synthesis in a PRMT1-dependent manner. Loss of PRMT1 or pharmacologic inhibition of FASN or protein S-palmitoyltransferase reversed chemoresistance in TNBC. Furthermore, IHC coupled with imaging MS in clinical TNBC specimens substantiated that PRMT1-mediated methylation of PHGDH, PFKFB3, and PKM2 correlates with chemoresistance and that metabolites required for methylation and fatty acid synthesis are enriched in TNBC. Together, these results suggest that enhanced de novo fatty acid synthesis mediated by coordinated protein arginine methylation and protein S-palmitoylation is a therapeutic target for overcoming chemoresistance in TNBC. SIGNIFICANCE: PRMT1 promotes chemoresistance in TNBC by methylating metabolic enzymes PFKFB3, PKM2, and PHGDH to augment de novo fatty acid synthesis, indicating that targeting this axis is a potential treatment strategy.