Different molecular subtypes can be identified in muscle-invasive bladder cancer. Although cisplatin-based neoadjuvant chemotherapy improves patient outcomes, we identified that the benefit is highest in patients with basal tumors. Our newly discovered classifier can identify these molecular subtypes in a single patient and could be integrated into routine clinical practice after further validation.
Molecular characterization of cell types using single-cell transcriptome sequencing is revolutionizing cell biology and enabling new insights into the physiology of human organs. We created a human reference atlas comprising nearly 500,000 cells from 24 different tissues and organs, many from the same donor. This atlas enabled molecular characterization of more than 400 cell types, their distribution across tissues, and tissue-specific variation in gene expression. Using multiple tissues from a single donor enabled identification of the clonal distribution of T cells between tissues, identification of the tissue-specific mutation rate in B cells, and analysis of the cell cycle state and proliferative potential of shared cell types across tissues. Cell type–specific RNA splicing was discovered and analyzed across tissues within an individual.
Muscle-invasive bladder cancer (MIBC) is an aggressive disease with limited therapeutic options. Although immunotherapies are approved for MIBC, the majority of patients fail to respond, suggesting existence of complementary immune evasion mechanisms. Here, we report that the PPARγ/RXRα pathway constitutes a tumor-intrinsic mechanism underlying immune evasion in MIBC. Recurrent mutations in RXRα at serine 427 (S427F/Y), through conformational activation of the PPARγ/RXRα heterodimer, and focal amplification/overexpression of PPARγ converge to modulate PPARγ/RXRα-dependent transcription programs. Immune cell-infiltration is controlled by activated PPARγ/RXRα that inhibits expression/secretion of inflammatory cytokines. Clinical data sets and an in vivo tumor model indicate that PPARγHigh/RXRαS427F/Y impairs CD8+ T-cell infiltration and confers partial resistance to immunotherapies. Knockdown of PPARγ or RXRα and pharmacological inhibition of PPARγ significantly increase cytokine expression suggesting therapeutic approaches to reviving immunosurveillance and sensitivity to immunotherapies. Our study reveals a class of tumor cell-intrinsic “immuno-oncogenes” that modulate the immune microenvironment of cancer.
Bladder cancer has the highest recurrence
rate of all cancers due
in part to inadequate transurethral resection. Inadequate resection
is caused by the inability of cystoscopes to detect invisible lesions
during the resection procedure. To improve detection and resection
of nonmuscle invasive bladder cancer, we quantified the ability of
a surface-enhanced Raman nanoparticle and endoscope system to classify
bladder tissue as normal or cancerous. Both antibody-based (active)
and tissue permeability-based (passive) targeting mechanisms were
evaluated by topically applying nanoparticles to ex vivo human bladder tissue samples. Multiplexed molecular imaging of CD47
and Carbonic Anhydrase 9 tumor proteins gave a receiver operating
characteristic area under the curve (ROC AUC of 0.93 (0.75, 1.00).
Furthermore, passively targeted nanoparticles enabled tissue classification
with an ROC AUC of 0.93 (0.73, 1.00). Passively targeted nanoparticles
penetrated 5-fold deeper and bound to tumor tissue at 3.3-fold higher
concentrations in cancer compared to normal bladder urothelium, suggesting
the existence of an enhanced surface permeability and retention effect
in human bladder cancer.
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