Intratumoral heterogeneity is a critical frontier in understanding how the tumor microenvironment (TME) propels malignant progression. Here, we deconvolute the human pancreatic TME through ...large-scale integration of histology-guided regional multiOMICs with clinical data and patient-derived preclinical models. We discover “subTMEs,” histologically definable tissue states anchored in fibroblast plasticity, with regional relationships to tumor immunity, subtypes, differentiation, and treatment response. “Reactive” subTMEs rich in complex but functionally coordinated fibroblast communities were immune hot and inhabited by aggressive tumor cell phenotypes. The matrix-rich “deserted” subTMEs harbored fewer activated fibroblasts and tumor-suppressive features yet were markedly chemoprotective and enriched upon chemotherapy. SubTMEs originated in fibroblast differentiation trajectories, and transitory states were notable both in single-cell transcriptomics and in situ. The intratumoral co-occurrence of subTMEs produced patient-specific phenotypic and computationally predictable heterogeneity tightly linked to malignant biology. Therefore, heterogeneity within the plentiful, notorious pancreatic TME is not random but marks fundamental tissue organizational units.
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•PDAC regional heterogeneity stems from sub-tumor microenvironments (subTMEs)•SubTMEs exhibit distinct immune phenotypes and CAF differentiation states•SubTMEs execute distinct tumor-promoting and chemoprotective functions•Intratumoral subTME co-occurrence links stromal heterogeneity to patient outcome
Intratumoral heterogeneity in the human pancreatic tumor microenvironment is not random but originates in well-definable regional tissue states. The underlying sub-tumor microenvironments shape regional epithelial and immune phenotypes and influence key clinical metrics of disease progression.
Breast cancer (BC) prognosis and outcome are adversely affected by obesity. Hyperinsulinemia, common in the obese state, is associated with higher risk of death and recurrence in BC. Up to 80% of BCs ...overexpress the insulin receptor (INSR), which correlates with worse prognosis. INSR’s role in mammary tumorigenesis was tested by generating MMTV-driven polyoma middle T (PyMT) and ErbB2/Her2 BC mouse models, respectively, with coordinate mammary epithelium-restricted deletion of INSR. In both models, deletion of either one or both copies of INSR leads to a marked delay in tumor onset and burden. Longitudinal phenotypic characterization of mouse tumors and cells reveals that INSR deletion affects tumor initiation, not progression and metastasis. INSR upholds a bioenergetic phenotype in non-transformed mammary epithelial cells, independent of its kinase activity. Similarity of phenotypes elicited by deletion of one or both copies of INSR suggest a dose-dependent threshold for INSR impact on mammary tumorigenesis.
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•Insulin receptor (INSR) is broadly expressed in breast cancer (BC)•INSR deletion suppresses mammary tumorigenesis driven by Her2 and PyMT oncogenes•INSR affects tumor initiation, not progression and metastasis•INSR upholds bioenergetic fitness of mammary epithelial cells
Insulin receptor (INSR) is found in most human breast cancers. Podmore et al. demonstrate that INSR contributes to cancer development in two mouse models representing major human breast cancer types by affecting the earliest stages of tumor development. Mechanistically, INSR supports cellular energy production necessary for malignant transformation.
To determine the impact of basal-like and classical subtypes in advanced pancreatic ductal adenocarcinoma (PDAC) and to explore GATA6 expression as a surrogate biomarker.
Within the COMPASS trial, ...patients proceeding to chemotherapy for advanced PDAC undergo tumor biopsy for RNA-sequencing (RNA-seq). Overall response rate (ORR) and overall survival (OS) were stratified by subtypes and according to chemotherapy received. Correlation of
with the subtypes using gene expression profiling,
hybridization (ISH) was explored.
Between December 2015 and May 2019, 195 patients (95%) had enough tissue for RNA-seq; 39 (20%) were classified as basal-like and 156 (80%) as classical. RECIST response data were available for 157 patients; 29 basal-like and 128 classical where the ORR was 10% versus 33%, respectively (
= 0.02). In patients with basal-like tumors treated with modified FOLFIRINOX (
= 22), the progression rate was 60% compared with 15% in classical PDAC (
= 0.0002). Median OS in the intention-to-treat population (
= 195) was 9.3 months for classical versus 5.9 months for basal-like PDAC (HR, 0.47; 95% confidence interval, 0.32-0.69;
= 0.0001).
expression by RNA-seq highly correlated with the classifier (
< 0.001) and ISH predicted the subtypes with sensitivity of 89% and specificity of 83%. In a multivariate analysis, GATA6 expression was prognostic (
= 0.02). In exploratory analyses, basal-like tumors, could be identified by keratin 5, were more hypoxic and enriched for a T-cell-inflamed gene expression signature.
The basal-like subtype is chemoresistant and can be distinguished from classical PDAC by GATA6 expression.
.
The molecular drivers of antitumor immunity in pancreatic ductal adenocarcinoma (PDAC) are poorly understood, posing a major obstacle for the identification of patients potentially amenable for ...immune-checkpoint blockade or other novel strategies. Here, we explore the association of chemokine expression with effector T-cell infiltration in PDAC.
Discovery cohorts comprised 113 primary resected PDAC and 107 PDAC liver metastases. Validation cohorts comprised 182 PDAC from The Cancer Genome Atlas and 92 PDACs from the Australian International Cancer Genome Consortium. We explored associations between immune cell counts by immunohistochemistry, chemokine expression, and transcriptional hallmarks of antitumor immunity by RNA sequencing (RNA-seq), and mutational burden by whole-genome sequencing.
Among all known human chemokines, a coregulated set of four (
, and
) was strongly associated with CD8
T-cell infiltration (
< 0.001). Expression of this "4-chemokine signature" positively correlated with transcriptional metrics of T-cell activation (
, and
), cytolytic activity (
and
), and immunosuppression (
, and
). Furthermore, the 4-chemokine signature marked tumors with increased T-cell activation scores (MHC I presentation, T-cell/APC costimulation) and elevated expression of innate immune sensing pathways involved in T-cell priming (STING and NLRP3 inflammasome pathways, BATF3-driven dendritic cells). Importantly, expression of this 4-chemokine signature was consistently indicative of a T-cell-inflamed phenotype across primary PDAC and PDAC liver metastases.
A conserved 4-chemokine signature marks resectable and metastatic PDAC tumors with an active antitumor phenotype. This could have implications for the appropriate selection of PDAC patients in immunotherapy trials.
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