Intratumoral Expression Research Articles

ADAMTS12 promotes oxaliplatin chemoresistance and angiogenesis in gastric cancer through VEGF upregulation

BackgroundWhile ADAMTS12 (A disintegrin and metalloproteinase with thrombospondin motifs 12) has been established as an important regulator of gastrointestinal tumor development and angiogenic activity, the precise mechanistic functions of ADAMTS12 have yet to be fully clarified in gastric cancer (GC). Accordingly, this study was developed to explore the molecular functions of ADAMTS12 in GC and to examine its utility as a biomarker associated with chemoresistance and prognostic outcomes in this cancer type. MethodsThe ability of ADAMTS12 to modulate the proliferative, migratory, invasive, chemoresistant, and tube formation activity of tumor cells was assessed in vivo and in vitro through gain- and loss-of-function approaches. Correlations between ADAMTS12, CD31, and VEGF expression levels in GC patient tumor tissue samples from individuals that did and did not undergo neoadjuvant chemotherapy (NAC) treatment were analyzed via immunohistochemical staining. ResultsThese analyses revealed the ability of ADAMTS12 to promote in vivo and in vitro cellular proliferative and angiogenic activity, promoting the activation of ERK and the consequent upregulation of VEGF, thereby inducing angiogenesis and decreasing GC cell oxaliplatin sensitivity. A positive correlation between ADAMTS12 levels and both the expression of VEGF as well as the density of microvessels was observed in GC patient tumor tissues. Moreover, those GC patients exhibiting higher intratumoral ADAMTS12 expression exhibited worse responses to NAC treatment and worse overall survival outcomes. ConclusionsThese findings suggest that ADAMTS12 can modulate signaling via the MAPK/VEGF axis in GC cells to enhance tumor cell resistance to oxaliplatin treatment under hypoxic and normoxic conditions. Elevated ADAMTS12 levels can additionally predict vascular abnormalities, worse survival outcomes, and chemoresistance in patients with GC.

Characteristics and prognosis of adolescent and young adult breast cancer.

16 Background: Adolescent and young adult (AYA)-generation breast cancer has characteristics of high clinicopathological malignancy and poor prognosis compared to cancers of other age groups. In recent advances in cancer research, the tumor microenvironment is involved in cancer invasion. In this study, we investigated the biology of AYA-generation breast cancer and the prognostic effects of the cancer microenvironment in breast cancer patients. Methods: In the current study, we analyzed 2042 breast cancer patients with clinical and intratumoral gene expression data from the open public databases TCGA and METABRIC. Patients aged 15-39 were defined as AYA-generation breast cancer, and patients aged 40-65 as middle-aged breast cancer. Tumor biology and cancer microenvironment were assessed using gene set enrichment analysis (GSEA) and the xCell algorithm. Disease-specific survival (DSS) and disease-free survival (DFS) were used to evaluate the prognosis of AYA-generation breast cancer compared to that of middle-aged and elderly breast cancer. Results: In METABRIC, the proportion of advanced stages was higher in AYA generation breast cancer than in middle-aged and elderly breast cancer (p<0.01). However, this was not the case with TCGA cohort. In the prognostic analysis, AYA-generation breast cancer showed shortened DSS and DFS compared with middle-aged breast cancer only in METABRIC. To clarify the association between prognosis and cancer biology, we performed GSEA. AYA-generation breast cancer enriched cell proliferation-related gene sets such as E2F Targets, G2M Checkpoints, and MYC Targets V1 in METABRIC. The analysis of TCGA also confirmed this result. Interestingly, the infiltration of macrophage M1 (p<0.001) and helper T cell Th1 (p=0.007), which act as tumor suppressors, was significantly higher in AYA generation breast cancer in METABRIC cohort. In TCGA, there was only a tendency for Th1 infiltration to be high in AYA generation breast cancer. Conclusions: AYA-generation breast cancer enriched gene sets associated with cell proliferation which might explain the worse prognosis of AYA-generation breast cancer.

Intratumoral NKp46+ natural killer cells are spatially distanced from T and MHC-I+ cells with prognostic implications in soft tissue sarcoma.

Soft tissue sarcomas (STS) are rare, heterogenous malignancies with an unmet need for novel immunotherapies. Tumor infiltrating lymphocytes (TILs) have been linked with favorable outcomes in STS patients, though the contribution of natural killer (NK) cells and spatial relationships of TILs with MHC-I expressing cells lacks detailed characterization. Using archived and prospectively collected specimens, we evaluated intratumoral NK cells by immunohistochemistry (IHC), flow cytometry, and immunofluorescence (IF). We assessed spatial localization of NK and T cells by multiplex IF, analyzing the effects of MHC-I expression status on NK and T cell clustering. Both intratumoral NKp46 and CD56dim expression were associated with significantly improved overall survival (P=0.05), while higher infiltrates of CD56bright NK cells predicted a worse prognosis (P=0.05). The presence of intratumoral NK cells was inversely proportional to CD3+ T cells. Spatial analyses showed NK cells preferentially clustering close to other NK cells with sparse CD3+ T and CD8+ T cells in range (P<0.0001). Additionally, CD3+ T and CD8+ T cells showed significantly greater co-localization with MHC-I+ cells, compared to NK cells (P<0.0001). After neoadjuvant radiotherapy, there was greater CD8 clustering, while after neoadjuvant chemotherapy, there was overall lower TIL clustering. Intratumoral NK cells are prognostic in STS and localize closer to MHC-I- cells than T cells. Although both NK and T cells are associated with improved survival in STS, their differential distribution in the TME based on MHC-I expression status may serve as a biomarker for improved immunotherapy treatment selection.

Characteristics associated with spatially resolved immune landscapes in triple-negative breast cancer in the FinXX trial and Mayo Clinic cohort.

581 Background: Several studies have established the crucial role of preexisting immune response measured by tumor-infiltrating lymphocytes (TILs) in triple-negative breast cancer (TNBC). Emerging studies showed that not only the number of TILs but also the location of TILs is as critical. There are 3 distinct immune landscapes described based on the locations of TILs, namely immune enriched (IN), immune excluded (IE), and immune desert (ID), which are associated with outcomes in TNBC treated with immune-checkpoint inhibitors. Here we evaluated characteristics associated with each immune landscape. Methods: NanoString IO360, Digital Spatial Profiling (DSP), and CosMx, a spatial multi-omics single-cell imaging platform, were used. DSP was used to quantify 39 immune-related proteins in stromal and tumor-enriched segments from 44 TNBC samples from the FinXX trial (NCT00114816) and 276 samples from the Mayo Clinic (MC) TNBC cohort (Leon-Ferre BCRT 2018). CosMx was performed in 75 samples from the MC TNBC cohort. First, tumors with TIL quantified by H&amp;E ≤ 30% were classified as ID. The rest of the tumors were categorized according to the intratumoral CD8 protein expression by DSP, with IE having intratumoral CD8 in the lower median and IN having intratumoral CD8 in the upper median. Differential expression listed as log fold change (FC) was estimated from the linear mixed model with significance defined as two-sided p &lt; 0.05. Results: Using DSP in the FinXX trial, intratumoral and stromal higher HLA-DR (FC 1.68, p = 0.001), B2M (FC 0.8, p = 0.005), CD4 (FC 0.74, p = 0.01), and CD40 (FC 1.56, p = 0.001) were associated with IN compared to ID. When comparing IE and IN, higher intratumoral CD11c (FC 0.97, p = 0.01) and stromal CD4 (FC 0.89, p = 0.047), CD20 (FC 0.85, p = 0.016), CD40 (FC 0.95, p = 0.045), and CD27 (FC 0.84, p = 0.024) were associated with IN. Similar findings were observed in the MC cohort. Moreover, intratumoral NY-ESO-1 expression (FC 0.55, p = 0.03) was associated with IN. Using GSEA with IO360 in the FinXX trial, PI3K-Akt signaling was associated with ID compared to IN (p = 0.01). We further evaluated the differential gene expression in a spatially resolved manner using CosMx with single-cell sequencing in the MC cohort. Expressions of MHC class I and class II in tumor cells, including HLA-A, HLA-B, HLA-C, HLA-DRA, HLA-DRB1, HLA-DPA1, and HLA-E, were associated with IN compared to ID and IE. Conclusions: Using an in-depth analysis with spatially defined context, we identified characteristics associated with distinct immune landscapes in TNBC. Our study highlights the potential future implications of intratumoral MHC expression, CD40, and PI3K-AKT as biomarkers and therapeutic targets. Clinical trial information: NCT00114816 .

Radiation fractionation effect on IDO1 through NF-kB/COX2 axis in non-small cell lung cancer.

e20613 Background: Lung cancer is the leading cancer mortality worldwide. Radiotherapy(RT) plays an important role in lung cancer treatment. Different does fractionation of RT has different effects on the prognosis of lung cancer. For example, stereotactic body radiotherapy can significantly improve the prognosis compared with conventionally Fractionated Radiotherapy. In non-small cell lung cancer, we have previously shown that Indoleamine 2,3-dioxygenase 1 (IDO1) metabolites and radiation induced changes had significant effects on long-term survival in patients treated with either Stereotactic body Radiation Therapy of 10Gy fraction size or conventional fractionated radiotherapy of 2Gy fraction size. However, the underlining molecular mechanism is unknown. In this study, we aimed to elaborate the molecular mechanism of such clinical differential effects in the laboratory. Methods: This study applied two dose/fractionation regimens with a similar BED10: 10Gyx1 and 2Gyx8. 10Gyx1 and 2Gyx8 were tested in cell lines of A549, H1299, Calu-1, TC-1 of human and murine NSCLC as well as normal rat cardiomyocyte cell line H9c2, and in vivo (TC-1 implanted C57Bl/6 mice). The mRNA and protein levels of IDO1, p-NF-kB, COX2 from cells and tumor tissues were determined by using qPCR, western blot and immunohistochemistry. Survival outcome was tested by colony formation assay in vitro and tumor growth curve in vivo. Results: In vitro, 10Gyx1 and 2Gyx8 induced IDO1 expression in all tested cell lines and the level of IDO1 expression induced by 10Gyx1 was lower than 2Gyx8. Both 10Gyx1 and 2Gyx8 increased p-NF-kB and COX2 expression and the level induced by 10Gyx1 was lower than 2Gyx8. In tumor bearing mice, two dose/fractionation regimens also induced intratumor IDO1 expression and increased the levels of p-NF-kB and COX2. Interestingly, the increased levels of IDO1, p-NF-kB, COX2 after 10Gyx1 were also significantly lower than 2Gyx8 in vivo. IDO inhibitor synergized with RT and enhanced cell killing efficacy of RT. Conclusions: The findings of this study suggest different does fractionation of RT induced up-regulation of IDO1 through NF-kB/COX2 axis in NSCLC and non-cancerous cell lines, what’s more, hypofractionated radiotherapy 10Gyx1 had less upregulation that of conventionally fractionated radiotherapy 2Gy x8 on IDO1 immune inhibitory pathway. The finding of hypofractionated radiotherapy less immune suppression differ from the traditional belief of more immune stimulation. Our current study provides a rationale in using IDO1 as a biomarker to design RT dose fractionation and/or immunotherapy in combination and possibilities for clinical trials to design IDO1 inhibitors in combination with radiotherapy.

NeoIRX trial: Immunologic induction with peri-lymphatic cytokines to enhance pembrolizumab (pembro) response in stage II/III triple-negative breast cancer (TNBC).

604 Background: The addition of pembro to neoadjuvant chemotherapy (NACT) improves pathological complete response (pCR) rate and recurrence-free survival in stage II/III TNBC, albeit with substantial chemotherapy-attributed toxicity. We hypothesize that locoregional cytokine therapy could be combined with pembro to optimize immune response and clinical outcome. In a phase Ib early-stage breast cancer trial, we previously demonstrated that peri-lymphatic cytokine injection (IRX-2 regimen, comprised of physiologic doses of IL-2, IFNg, and other cytokines derived from activated donor lymphocytes, given with low-dose cyclophosphamide) is well tolerated and associated with increased intratumoral lymphocytes, T-cell activation, and PD-L1 expression. Here, we report preliminary outcomes of neoIRX, a phase II trial evaluating induction IRX-2 + pembro preceding NACT + pembro. Methods: Subjects with stage II/III TNBC were randomized to receive induction pembrolizumab (all subjects: 200mg IV) +/- peri-areolar IRX-2 (IRX-2 arm: 1 ml SQ x2 daily for 10 days + cyclophosphamide 300 mg/m2 IV x 1) preceding initiation of NACT + pembro. The primary endpoint was pCR rate following NACT + pembro (n = 15 subjects/arm planned); secondary endpoints were safety and tolerability. We explored post-induction/pre-NACT radiographic (ultrasound) and histologic outcomes (TILs, tumor regression) as a biomarker strategy to predict pCR. Results: The trial terminated after n = 12 subjects due to withdrawal of drug support for IRX-2. The IRX-2 arm achieved 83% pCR (n = 5/6, CI 36-100%) compared to 33% pCR with pembro alone (n = 2/6, CI 4-78%). The regimen was well-tolerated with minimal IRX-2-attributed toxicities (67% grade I skin bruise). Toxicities during NACT + pembro were similar to Keynote-522. 67% (n = 4/6) of IRX-2 subjects experienced week 3 radiographic regression, with evidence of brisk lymphocyte infiltration on week 3 biopsy, and with 100% pCR rate (n = 4/4) following NACT + pembro. n = 2/6 subjects receiving pembro+IRX-2 experienced pCR on week 3 biopsy, versus n = 0/3 evaluable in control arm. Conclusions: Induction IRX-2 + pembro is well tolerated and is associated with encouraging outcomes, supporting further study of peri-lymphatic induction cytokine therapy in stage II/III TBNC. Post-induction radiographic and histologic outcomes may identify patients with immune-responsive tumors, for whom NACT de-escalation may be a promising therapeutic approach to mitigate toxicity. Clinical trial information: NCT04373031 .

Sunitinib attenuates reactive MDSCs enhancing anti-tumor immunity in HNSCC

Enhancer of zeste homolog 2 (EZH2) is implicated in promoting HNSCC malignant progression. However, EZH2 inhibitors, when used alone, increase the number of myeloid-derived suppressor cells (MDSCs), which are responsible for enhancing tumor stemness and promoting tumor immune escape. We aimed to determine whether combining tazemetostat (an EZH2 inhibitor) and sunitinib (a MDSC inhibitor) can improve the response rate to an immune-checkpoint-blocking (ICB) therapy. We evaluated the efficacy of the above treatment strategies by bioinformatics analysis and animal experiments. EZH2 overexpression and abundant MDSCs in patients with HNSCC are associated with tumor progression. Tazemetostat treatment alone had limited inhibitory effect on HNSCC progression in the mouse models, accompanied by a surge in the number of MDSCs in the tumor microenvironment. Conversely, the combined use of tazemetostat and sunitinib reduced the number of MDSCs and regulatory T cell populations, promoting intratumoral infiltration of T cells and inhibiting of T cell exhausting, regulating of wnt/β-catenin signaling pathway and tumor stemness, promoting the intratumoral PD-L1 expression and improved the response rate to anti-PD-1 therapy. The combined use of EZH2 and MDSC inhibitors effectively reverses HNSCC-specific immunotherapeutic resistance and is a promising strategy for overcoming resistance to ICB therapy.

Effect of DUAL pharmacological blockade of AURKA and PD-L1 pathways on plasticity and metastasis for triple negative breast cancer.

e13100 Background: Aurora-A mitotic kinase (AURKA) plays a pivotal role in Triple Negative Breast Cancer (TNBC) progression through activation of epithelial to mesenchymal transition (EMT)-mediated cancer cell plasticity. Cancer cells that undergo EMT acquire a CD44high/CD24low and/or ALDHhigh cancer stem-like phenotype (Cancer Stem Cells) characterized by high self-renewal capacity and intrinsic drug resistance. Cancer Stem Cells (CSCs) also shows high PD-L1 expression that plays a critical role in inducing tumor immune escape through CD8+ T-cells exhaustion. For these reasons, molecular characterization of oncogenic pathways that promote stemness and intra-tumoral PD-L1 expression is essential to evaluate whether novel combinatorial therapeutic strategies aimed to inhibit cancer cell plasticity, immune evasion capacity and organ metastasis may impact cancer progression. Methods: (1) TNBC Models: MDA-MB 231 and variant MDA-MB 231/LM cells, and unique TNBC-M40 cells established from metastatic PDXs; (2) In Vitro Studies: TNBC cells were treated with the AURKA inhibitor alisertib (50nM). PD-L1 expression was evaluated by immunoblotting assay. Apoptosis was measured by immunofluorescence using Cleaved-PARP antibodies. To assess stemness capacity, TNBC cells were cultured under non-adherent conditions to form mammospheres. ALDH activity (functional stemness marker) was measured using the Aldefluor Kit. (3) In Vivo Studies: 1x106 MDA-MB 231/LM cells were injected into the mammary fat pad of humanized NSG-CD34+ female mice. Animals were randomized into four groups (5 mice per group) and treated with anti-PD-L1 ICI atezolizumab (20 mg/Kg) and alisertib (25 mg/Kg) as monotherapy or in combination. Control groups were treated with saline solution placebo. PD-L1, CD44, Vimentin expression and tumor infiltration of CD8+ T-cells were assessed by immunofluorescence. Results: Treatment of MDA-MB 231/LM xenografts with alisertib decreased the levels of CD44 and PD-L1 expression and increased CD8+ T-cells tumor infiltration. Because PD-L1 genetic targeting enhanced in vitro alisertib-induced apoptosis, MDA-MB 231/LM xenografts were treated with alisertib and the anti-PD-L1 ICI atezolizumab. Combination of atezolizumab and alisertib resulted in the reduced expression of the EMT marker vimentin that was linked to lack of organ metastasis. Remarkably, combination of atezolizumab and alisertib also induced a significant reduction of ALDHHigh CSC in ex-vivo 3D-Organoids established from TNBC-M40 cells. Conclusions: This study provides innovative pre-clinical rationale for combining AURKA inhibitors with ICIs to impair cancer cell plasticity, immune evasion capacity and halt the progression of metastatic TNBCs that currently has limited effective therapeutic options.

Association of tumor-infiltrating lymphocytes (TILs) with clinicopathologic characteristics and prognosis in young women with HR+/HER2- breast cancer (BC).

505 Background: Increased TILs are associated with better prognosis in triple-negative BC, including in patients (pts) age &lt; 40. However, the role of TILs remains unclear in HR+/HER2- BC and little data exist in young pts, in whom immune microenvironment could be altered by age-related host/tumor differences. We assessed the extent and composition of immune infiltration in HR+ tumors of young women and correlated with clinicopathologic features and survival outcomes. Methods: From a prospective cohort study of women with BC diagnosed age ≤40, we identified those with stage I-III HR+/HER2- BC and available pre-treatment (tx) tumor tissue. Multiplexed immunofluorescence was used to quantify cytotoxic T (CD8+), T helper (Th, CD3+CD8-), T regulatory (Tregs, FOXP3+CD3+) and exhausted T (PD1+CD8+) cells in stroma and tumor. Univariate analyses tested associations between clinicopathologic variables and immune markers by high or low expression, divided based on median. High vs. low TILs were evaluated in Cox regression analyses for invasive breast cancer-free survival (iBCFS), distant disease-free survival (DDFS) and overall survival (OS). Results: In 390 pts, median age was 37 years (21-40), most had grade 2 (51%), T1 (65%), N0 (63%) tumors and 67% received adjuvant chemotherapy. Black pts (n = 17) had higher expression of stromal CD8+ ( P= .010), FOXP3+CD3+ ( P= .027) and PD1+CD8+ TILs ( P= .043); intratumoral TILs did not differ by race. Older age (36-40) was associated with high expression of CD8+ ( P= .033) and PD1+CD8+ TILs ( P= .031) within stroma and CD3+CD8- TILs within tumor ( P= .046). Grade 3 tumors had higher stromal and intratumoral expression of CD3+CD8- ( P= .002; P&lt; .001) and FOXP3+CD3+ TILs ( P= .020; P&lt; .001). No differences in TILs were seen according to recency of pregnancy, BRCA1/2 status or T/N stage. Over a median follow up of 8 years, 85 iBCFS events, 64 DDFS events and 37 deaths occurred. High stromal expression of CD3+CD8- TILs was associated with better iBCFS (HR 0.49, P= .002) and DDFS (HR 0.57, P= .046), which remained significant when adjusted for T/N stage, grade and chemotherapy (iBCFS HR 0.41, P&lt; .001; DDFS HR 0.45, P= .008). High stromal expression of CD3+CD8- and FOXP3+CD3+ TILs was associated with better OS (HR 0.47, P= .038) and iBCFS (HR 0.58, P= .018), respectively, on adjusted analyses only. High intratumoral expression of CD3+CD8- and FOXP3+CD3+ TILs was associated with better iBCFS (HR 0.59, P= .025; HR 0.63, P= .043) after adjustment only. Conclusions: The distribution of TIL subtypes in young women’s HR+ BC varied according to race, age and grade. High stromal and intratumoral expression of Th and Tregs was associated with improved BC outcomes. Characterization of immune cell subsets could help refine the prognostic value of TILs in HR+ BC, particularly in young pts who may benefit from individualized escalated/de-escalated tx strategies.

Upregulation of the Oct3/4 Network in Basal Breast Cancer Is Associated with Its Metastatic Potential and Shows Tissue Dependent Variability.

Adaptive plasticity of Breast Cancer stem cells (BCSCs) is strongly correlated with cancer progression and resistance, leading to a poor prognosis. In this study, we report the expression profile of several pioneer transcription factors of the Oct3/4 network associated with tumor initiation and metastasis. In the triple negative breast cancer cell line (MDA-MB-231) stably transfected with human Oct3/4-GFP, differentially expressed genes (DEGs) were identified using qPCR and microarray, and the resistance to paclitaxel was assessed using an MTS assay. The tumor-seeding potential in immunocompromised (NOD-SCID) mice and DEGs in the tumors were also assessed along with the intra-tumor (CD44+/CD24-) expression using flow cytometry. Unlike 2-D cultures, the Oct3/4-GFP expression was homogenous and stable in 3-D mammospheres developed from BCSCs. A total of 25 DEGs including Gata6, FoxA2, Sall4, Zic2, H2afJ, Stc1 and Bmi1 were identified in Oct3/4 activated cells coupled with a significantly increased resistance to paclitaxel. In mice, the higher Oct3/4 expression in tumors correlated with enhanced tumorigenic potential and aggressive growth, with metastatic lesions showing a >5-fold upregulation of DEGs compared to orthotopic tumors and variability in different tissues with the highest modulation in the brain. Serially re-implanting tumors in mice as a model of recurrence and metastasis highlighted the sustained upregulation of Sall4, c-Myc, Mmp1, Mmp9 and Dkk1 genes in metastatic lesions with a 2-fold higher expression of stem cell markers (CD44+/CD24-). Thus, Oct3/4 transcriptome may drive the differentiation and maintenance of BCSCs, promoting their tumorigenic potential, metastasis and resistance to drugs such as paclitaxel with tissue-specific heterogeneity.

Phenotypic plasticity and reduced tissue retention of exhausted tumor-infiltrating Tcells following neoadjuvant immunotherapy in head and neck cancer.

Neoadjuvant immunotherapies (NITs) have led to clinical benefits in several cancers. Characterization of the molecular mechanisms underlying responses to NIT may lead to improved treatment strategies. Here we show that exhausted, tumor-infiltrating CD8+ T (Tex) cells display local and systemic responses to concurrent neoadjuvant TGF-β and PD-L1 blockade. NIT induces a significant and selective increase in circulating Tex cells associated with reduced intratumoral expression of the tissue-retention marker CD103. TGF-β-driven CD103 expression on CD8+ Tcells is reversed following TGF-β neutralization invitro, implicating TGF-β in Tcell tissue retention and impaired systemic immunity. Transcriptional changes implicate Tcell receptor signaling and glutamine metabolism as important determinants of enhanced or reduced Tex treatment response, respectively. Our analysis illustrates physiological and metabolic changes underlying Tcell responses to NIT, highlighting the interplay between immunosuppression, tissue retention, and systemic anti-tumor immunity and suggest antagonism of Tcell tissue retention as a promising neoadjuvant treatment strategy.

Higher Intra-Tumoral Expression of Pro-coagulation Genes Is a Predictor of Angiogenesis, Epithelial Mesenchymal Transition and Worse Patient Survival in Gastric Cancer

Coagulation regulates angiogenesis in cancer, and is associated with tumor development and metastasis. To date, there have been no studies quantifying the state of intra-tumoral coagulation. We measured intra-tumoral coagulation gene expression using the "Hallmark-COAGULATION" gene set in the MSigDB, performing gene set variation analysis and then assigning a "coagulation score" to quantify gene expression. Clinical, histologic, and genetic data were analyzed in 807 gastric cancer patients from the TCGA_STAD and GSE84437 databases. Tumors with increased expression of pro-coagulation genes were consistently associated with higher AJCC T-categories (p = 0.018), lymph node metastasis (p = 0.036), and stage (p = 0.006) in both cohorts. Patients with high coagulation scores were found to have worse disease-specific survival and overall survival (OS) (p = 0.019 and 0.011, respectively) in TCGA, and worse OS in GSE84437 cohort (p = 0.012). Higher expression of pro-coagulation genes correlated with increased intra-tumoral angiogenesis, as well as increased proportions of lymphatic and microvascular endothelial cells, endothelial cells, and pericytes, calculated by xCell algorithm. High coagulation scores were significantly associated with low tumor mutation burden, but not with intratumor heterogeneity and homologous recombination deficiency. Gastric cancers with high coagulation scores contained higher amounts of M1 macrophages and dendritic cells, and low numbers of Th1 cells (all P<0.001). Genes for epithelial mesenchymal transition (EMT), myogenesis, apical junction, transforming growth factor (TGF)-β signaling, and angiogenesis were enriched in high coagulation score-gastric cancers (all false discovery rate <0.25). In conclusion, gastric cancers expressing higher levels of pro-coagulation genes demonstrate increased angiogenesis, EMT, TGF-β signaling and worse patient prognosis.

Infiltration by Intratumor and Stromal CD8 and CD68 in Cervical Cancer.

Background and Objectives: The tumor microenvironment (TME) plays a major role in neoplastic development. Various types of cells can be found in the TME. These cells can be classified into two groups, immunosuppressive and immunostimulatory types, depending on the function they perform in the antitumor immune response (IR). By interacting both with each other and with tumor cells, different immune mechanisms are activated or inhibited, which can suppress or promote the development and progression of cervical cancer (CC). Our aim was to investigate some of the main components of the cellular immune response in TME-tumor-infiltrating cytotoxic T cells (Tc, CD8+) and tumor-associated macrophages (TAMs, CD68+)-in patients with CC. Materials and Methods: We analyzed 72 paraffin-embedded tumor tissues of patients diagnosed and treated at Medical University Pleven, Bulgaria. Patients were classified according to the 2018 FIGO (International Federation of Gynaecology and Obstetrics) classification. From each patient, we selected one histological slide with hematoxylin eosin staining. In a microscopic evaluation, CD8+ T lymphocytes and CD68+-positive macrophages were counted in the tumor and stroma of five randomly selected fields at ×40 magnification (HPF). We analyzed the relationship between intratumoral and stromal CD8 and CD68 expression and FIGO stage and N status. Results: There was no significant association between the expression levels of intratumoral and stromal CD68+ cells in the different FIGO stages and according to the lymph nodes' involvement. For CD8+ cells, the association of stromal infiltration was also not found, but T intratumor infiltration was associated with a higher FIGO stage, despite the fact that the results did not reach significance (p = 0.063, Fisher test). Intratumoral CD8+ cells were significantly associated with positive N status, (p = 0.035). Discussion: The separation of tumor-infiltrating cytotoxic T cells and tumor-associated macrophages into intratumoral and stromal is inconsequential. In our study, the level of infiltration of CD68+ cells in tumors and stromata was not significantly associated with tumor progression or lymph node involvement. The results were different for CD8+ cells, in which levels of infiltration were associated with lymph nodes' statuses. Conclusions: The separate evaluation of CD68+ immune cells in the TME as intratumoral and stromal is not beneficial for defining prognoses, since the presence of these cells is not associated with the patient's stage. In our study, the presence of CD8+ cells was significantly associated with lymph node metastases. The prognostic value of the obtained results can be enriched with an additional study of the lymphocyte phenotype, including B and other subtypes of T lymphocytes, NK cells, as well as molecules involved in the immune response, such as HLA subtypes.

Abstract 6686: Tumor suppressor miRNA-665 based serum biomarker for detecting pancreatobiliary cancer

Abstract Background: MicroRNA-665 (miR-665), an intracellular inhibitor of pancreatic cancer (PC) cells, might be a potential biomarker to detect pancreatobiliary cancer (PBca). We sought to determine the diagnostic ability of miR-665 as a serum biomarker for PBca, and to explore the role of miR-665 in PC. Methods: This multicenter study enrolled patients with treatment-naïve PBca and healthy participants. PBca-related serum miRNAs were determined using weighted co-expression network analysis of a comprehensive serum miRNA microarray dataset in an exploratory cohort. Using various combinations of PBca-related serum miRNAs, Fisher’s linear discriminant analyses provided miRNA signatures to discriminate PBca from healthy controls. MiRNA signatures with a sensitivity/specificity (SN/SP) of ≥80/80% and high AUC in comparison with the AUC of CA19-9 were defined as the diagnostic miRNA signature in exploratory, validation and independent validation cohorts, whose accuracy was confirmed by 5-fold cross validation. Biology of the diagnostic miRNAs was evaluated using biopsy samples from liver metastasis of PC patients and human PC cells. Results: We analyzed 496 of 1487 enrolled subjects (150 healthy and 134 PBca, 50 healthy and 47 PBca, and 50 healthy and 46 PBca subjects in the exploratory, validation and independent validation cohorts, respectively). Among miRNA signatures from 82 PBca-related miRNAs, a five serum miRNA combination containing miR-665 was identified as the diagnostic miRNA signature in all three cohorts. SN/SP and AUC in the validation and independent validation cohorts were 92/88% and 0.95 (CA19-9: 81/92% and 0.94) and 87/80% and 0.91 (CA19-9: 80/98% and 0.87), respectively. In sub-population analysis for detecting 48 resectable PCs, the discriminative ability of the diagnostic miRNA signature plus CA19-9 (SN/SP: 90/78%) was superior in sensitivity to that of CA19-9 alone (60/94%). In seven PC patients with liver metastasis, high expression of intratumor miR-665 tended to correlate with high serum miR-665 level (r = 0.56) and low expression of intratumor phospho-Erk expression (r = 0.57). Transfection of miR-665 to a human PC cell led to cell growth suppression. Conclusions: This study identified the diagnostic ability of a tumor suppressor miR-665-based serum miRNA signature for PBca. For detecting resectable PC, a miR-665-based serum miRNA signature plus CA19-9 is a superior biomarker to CA19-9 alone. Citation Format: Shuichi Mitsunaga, Makoto Ueno, Masahiro Tsuda, Takamichi Kuwahara, Yukiko Takayama, Keiji Hanada, Hitoshi Yoshida, Kenji Takahashi, Kohei Nakata, Hideaki Iwama, Masafumi Ikeda, Satoshi Kobayashi, Ikuya Miki, Kazuo Hara, Ryota Higuchi, Akinori Shimizu, Tomohiro Nomoto, Hidetaka Iwamoto, Masafumi Nakamura, Etsuro Hatano, Hiroko Sudo, Satoko Takizawa, Atsushi Ochiai. Tumor suppressor miRNA-665 based serum biomarker for detecting pancreatobiliary cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6686.

Abstract 3990: Imaging molecular alterations during tucatinib response in preclinical models of HER2+ breast cancer

Abstract Introduction: Human epidermal growth factor receptor 2 (HER2) is overexpressed in 25% of breast cancers. Tucatinib, a small molecule HER2 inhibitor, was FDA approved for inoperable or metastatic HER2+ breast cancer. As many of these patients have inoperable tumors, there is a need to identify imaging metrics that can characterize response to tucatinib. Positron emission tomography (PET) imaging can quantify changes in the tumor microenvironment that precede changes in tumor size through imaging with radiopharmaceuticals that target proliferation (fluorothymidine, [18F]-FLT), hypoxia (fluoromisonidazole, [18F]-FMISO) and HER2 expression ([89Zr]-Pertuzumab). The goal of this study is to use advanced PET imaging to non-invasively monitor response to tucatinib in HER2+ primary breast cancer and quantify the subsequent tumor microenvironment modulation. Methods: HER2+ cell line (BT474) and patient derived xenograft (BCM 3472) tumor models were engrafted and developed to 270 ± 166.4 mm3 before being enrolled into experiments. Mice were treated with 50 mg/kg tucatinib via PO and were imaged with [18F]-FLT PET (N = 8) on days 0, 3 and 7, [18F]-FMISO PET (N = 6) on days 0, 3 and 7, or [89Zr]-Pertuzumab PET (N = 5) on days 0 and 14. Intratumoral proliferation, hypoxia and HER2 expression were quantified with standardized uptake value (SUV). Following the final imaging timepoint, tumors were excised for immunohistochemistry against Ki-67 (proliferation), pimonidazole (hypoxia), and HER2. A non-parametric T-test was used to assess for significance. Results: Tucatinib treated BT474 and BCM3472 tumors had a 2.07 and 2.63 fold decrease in tumor volume, respectively (p&amp;lt;0.01). Tucatinib treated BT474 and BCM3472 tumors had significantly decreased hypoxia and proliferation, relative to control tumors (p&amp;lt;0.05). Tucatinib treated BT474 tumors had significantly decreased HER2 expression (p&amp;lt;0.05); however, no significant change in HER2 expression was observed in tucatinib treated BCM3472 tumors. Conclusion: Tucatinib significantly decreases tumor volume and decreases intratumoral proliferation and hypoxia in both cell-line and patient-derived xenograft models of HER2+ breast cancer. Our data suggests molecular imaging may drive understanding of and predict response to tucatinib therapy. Acknowledgements: Tucatinib was provided by Seagen Inc. Bothell, Washington, USA. Citation Format: Patrick Song, Ameer Mansur, Anna Sorace. Imaging molecular alterations during tucatinib response in preclinical models of HER2+ breast cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3990.

Abstract 2147: Decoding the natural biology of triple-negative breast cancer and response to chemotherapy by single-cell transcriptomics

Abstract Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that lacks the expression of estrogen receptor (ER), progesterone receptor (PR) and HER2 and therefore have limited hormonal treatment options. Neoadjuvant chemotherapy (NAC) is backbone of treatment for TNBC, and about 50% of patients respond well leading to pathological complete response (pCR). However, the remaining patients develop resistance to NAC and progress to metastatic disease and poor survival in 1-2 years after the initial treatment. Previous studies have performed bulk RNA expression profiling of TNBC patients and identified 5-6 subgroups of patients, however these studies could not resolve expression programs at single cell resolution to distinguish between the tumor cells and different components of the tumor microenvironment (TME). Here we performed scRNA-seq of pre-treatment fresh core biopsy tissue samples from TNBC patients in the ARTEMIS clinical trial and compared these data between pCR and non-pCR patients to identify programs associated with response to NAC. We also compared these data to scRNA-seq data from patients with disease-free breast tissue to understand the basic biology of TNBC and identify cell types that are reprogrammed in malignant disease. Using the single cell tumor cell data, we identified 4 archetypes of TNBC which represent patient-level intertumor expression programs: luminal secretory-like (LS), basal/luminal-like (BL), immunoregulatory (IM), and luminal androgen receptor (LAR). Notably, the archetype BL was associated with non-pCR, while IM was associated with pCR. We further identified 13 metatraits, which are unique intratumoral expression programs that are shared across patients. Across the cancer cells, we identified 13 metatraits such as cell cycling, stress, hypoxia, interferon response, HLA, partial epithelial-mesenchymal transition, and endoplasmic reticulum stress, many of which corresponded to NAC response. In the immune compartment, we found 15 myeloid cell states, 14 T/NK cell states, and 6 B cell states, several of which corresponded to pCR/non-pCR. Similarly, in the stromal compartment, there were 4 fibroblast cell states, 4 pericyte cell states, and 7 endothelial cell subtypes, of which several cell states were associated with NAC response. Overall, these data report the natural biology of TNBC patients and malignant cell states that are reprogrammed in malignant disease, as well as their correspondence to NAC response, providing new data to predict which TNBC patients are likely to respond to chemotherapy. Citation Format: Tapsi Kumar, Yiyun Lin, Yun Yan, Shanshan Bai, Jianzhuo Li, Tuan Tran, Min Hu, Elizabeth Ravenberg, Maia Rauch, Alyson Clayborn, Alastair Thompson, Lei Huo, Stacy Moulder, Clinton Yam, Nicholas Navin. Decoding the natural biology of triple-negative breast cancer and response to chemotherapy by single-cell transcriptomics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2147.

Conditional expression of endorepellin in the tumor vasculature attenuates breast cancer growth, angiogenesis and hyaluronan deposition.

The tumor stroma of most solid malignancies is characterized by a pathological accumulation of pro-angiogenic and pro-tumorigenic hyaluronan driving tumorigenesis and metastatic potential. Of all three hyaluronan synthase isoforms, HAS2 is the primary enzyme that promotes the build-up of tumorigenic HA in breast cancer. Previously, we discovered that endorepellin, the angiostatic C-terminal fragment of perlecan, evokes a catabolic mechanism targeting endothelial HAS2 and hyaluronan via autophagic induction. To explore the translational implications of endorepellin in breast cancer, we created a double transgenic, inducible Tie2CreERT2;endorepellin(ER)Ki mouse line that expresses recombinant endorepellin specifically from the endothelium. We investigated the therapeutic effects of recombinant endorepellin overexpression in an orthotopic, syngeneic breast cancer allograft mouse model. First, adenoviral delivery of Cre evoking intratumor expression of endorepellin in ERKi mice suppressed breast cancer growth, peritumor hyaluronan and angiogenesis. Moreover, tamoxifen-induced expression of recombinant endorepellin specifically from the endothelium in Tie2CreERT2;ERKi mice markedly suppressed breast cancer allograft growth, hyaluronan deposition in the tumor proper and perivascular tissues, and tumor angiogenesis. These results provide insight into the tumor suppressing activity of endorepellin at the molecular level and implicate endorepellin as a promising cancer protein therapy that targets hyaluronan in the tumor microenvironment.

Fusion peptide is superior to co-expressing subunits for arming oncolytic herpes virus with interleukin 12

BackgroundG47∆ is a triple-mutated oncolytic herpes simplex virus type 1 (HSV-1) recently approved as a new drug for malignant glioma in Japan. As the next-generation, we develop armed oncolytic HSV-1 using G47∆ as the backbone. Because oncolytic HSV-1 elicits specific antitumor immunity, interleukin 12 (IL-12) can function as an effective payload to enhance the efficacy.MethodsWe evaluate the optimal methods for expressing IL-12 as a payload for G47∆-based oncolytic HSV-1. Two new armed viruses are generated for evaluation by employing different methods to express IL-12: T-mfIL12 expresses murine IL-12 as a fusion peptide, with the genes of two subunits (p35 and p40) linked by bovine elastin motifs, and T-mIL12-IRES co-expresses the subunits, with the two genes separated by an internal ribosome entry site (IRES) sequence.ResultsT-mfIL12 is significantly more efficient in producing IL-12 than T-mIL12-IRES in all cell lines tested, whereas the expression methods do not affect the replication capabilities and cytopathic effects. In two syngeneic mouse subcutaneous tumor models of Neuro2a and TRAMP-C2, T-mfIL12 exhibits a significantly higher efficacy than T-mIL12-IRES when inoculated intratumorally. Furthermore, T-mfIL12 shows a significantly higher intratumoral expression of functional IL-12, causing stronger stimulation of specific antitumor immune responses than T-mIL12-IRES.ConclusionsThe results implicate that a fusion-type expression of IL-12 is a method superior to co-expression of separate subunits, due to higher production of functional IL-12 molecules. This study led to the creation of triple-mutated oncolytic HSV-1 armed with human IL-12 currently used in phase 1/2 trial for malignant melanoma.

Loss of viral genome with altered immune microenvironment during tumour progression of Epstein-Barr virus-associated gastric carcinoma.

Epstein-Barr virus (EBV) is one of the major drivers of gastric carcinogenesis. EBV infection is established before tumour initiation and is generally maintained throughout tumour development; however, the significance of EBV in tumour maintenance and progression remains to be elucidated. Here, we report eight cases of EBV-associated gastric carcinoma (EBVaGC) with intratumoural heterogenous expression of EBV-encoded small RNA (EBER), a highly expressed latent gene of EBV, and demonstrate clinicopathological characteristics of these rare cases. By performing detailed histological assessment of EBER-positive and -negative components of each case, detection of EBV genome in tumour cells by fluorescence in situ hybridisation, TP73 methylation analysis, whole exome sequencing, and targeted gene panel sequencing, we identified tumours in two patients to be collision tumours of different origins. In the other six patients, some genetic/epigenetic alterations were shared between EBER-positive and -negative components, suggesting that EBV was eliminated from tumour cells during progression. Interestingly, in both tumour types, programmed death ligand 1 and intratumoural infiltration of CD8+ T lymphocytes were lower in EBER-negative than in EBER-positive components, suggesting an immunogenic role of EBV. To the best of our knowledge, this study is the first to demonstrate the detailed histological features and genetic/epigenetic alterations in EBVaGC with heterogenous EBER expression; the loss of EBV may benefit tumour progression and immune evasion and might be clinically important for selecting treatment strategies for such cancers. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Immunohistochemical profiling of the tumour microenvironment in borderline and malignant ovarian tumours in young women.

Ovarian cancer is a major cause of cancer-related deaths in women. Our previous study highlighted the interaction between cancer cells and the host immune response in solid cancers. The present study aimed to analyse the proportion, density and distribution of T and B lymphocytes within the tumour and surrounding stroma, and their prognostic significance in young women with borderline and malignant ovarian surface epithelial tumours. Full clinicopathological and outcome data were collected for 57 women aged <50 years diagnosed between January 2010 and December 2015. Representative tumour sections were stained for CD3 (T cells) and CD20 (B cells) and tumour-infiltrating lymphocytes (TILs) were scored following the TILs Working Group Recommendations and described as stromal, intra-tumoural, lymphoid aggregates and touching lymphocytes. Data were statistically analysed and the association with clinicopathological variables was assessed. The median age was 41 years and the most common histological type was serous carcinoma (n=21). The risk of malignancy index was a significant predictor of ovarian cancer diagnosis (P<0.05). A total of 15 out of 34 patients with cancer died. There was significantly greater stromal infiltration of CD3 and CD20 TILs (P=0.01 and P=0.03, respectively) and higher intratumoral CD20 expression in ovarian epithelial cancers compared with borderline tumours. The highest CD3 stroma count and density were observed in serous carcinoma, which also exhibited the highest numbers of CD3 and CD20 aggregates. There was no statistically significant difference between touching lymphocytes and tumour histological subtype. There was no significant association between TIL expression and patient survival. The count, distribution and density of T and B lymphocytes in ovarian tumours varied depending on tumour type and invasiveness. Their topographic distribution within the tumour and surrounding stroma did not impact prognosis in young women with ovarian cancer. TIL analysis in an older age group of women with ovarian tumours is ongoing to determine its potential prognostic significance.