Malignant Stroma Research Articles

Phytochemicals and Their Nanoformulations for Targeting Hepatocellular Carcinoma: Exploring Potential and Targeting Strategies.

Hepatocellular carcinoma (HCC) continues to pose a global health concern, necessitating the exploration of innovative therapeutic approaches. In the recent decade, targeting tumor stroma consisting of extracellular matrix (ECM), immune cells, vascular system, hypoxia, and also suppressive mechanisms in HCC has attracted interest in repressing tumor growth and metastasis. Phytochemicals have attained considerable attention because of their manifold biological effects and high capacity for anticancer activities. These chemical agents have shown the capability to modulate different cells and secretions within the stroma of malignancies. In recent years, the development of nanoformulations has further enhanced the therapeutic potential of phytochemicals by improving their solubility, bioavailability, and targeted delivery to tumor tissues. This review aims to provide an encyclopedic overview of the potential of phytochemicals and their nanoformulations as promising therapeutic strategies for targeting HCC. The review initially highlights the broad array of phytochemicals exhibiting potent anticancer properties, including flavonoids, alkaloids, terpenoids, and phenolic compounds, among others. Then, the nanoformulations and modification of these agents will be reviewed. Finally, we will review the latest experiments that have examined the modulation of HCC using adjuvant phytochemicals and their nanoformulations.

Epithelial Carcinomas Arising within Phyllodes Tumours of the Breast: A Review of Their Pathological Characteristics.

Epithelial proliferation is a common feature of phyllodes tumours (PTs), but epithelial malignancy is rare. This review seeks to further our understanding of epithelial malignancy within PTs by analysing their histopathological characteristics in previously reported cases and providing an overview of studies on their pathological features. PubMed and DeepDyve were searched for case reports, case series, and literature reviews of in situ and invasive carcinoma within PTs. Only cases where the carcinoma was within the PT were included. Cases of synchronous carcinoma in the ipsilateral or contralateral breast were excluded. Ninety-eight cases of in situ or invasive carcinoma within a PT were identified. Across the grades of PTs, there was a similar proportion of invasive carcinomas compared to in situ lesions. Malignant PT correlates with a higher likelihood of epithelial malignancy, and molecular studies support a possible causal pathophysiological relationship. This higher likelihood may suggest interactions between malignant stroma and the transforming epithelium that could potentially play a significant role in the phenomenon, which remains to be elucidated. Encasement within a PT likely improves the prognosis of breast carcinoma due to earlier detection. The presence of carcinoma within a malignant PT has uncertain prognostic implications. Thorough sampling of all PTs is recommended for appropriate prognostication and management.

Abstract 4462: Immunoregulatory effects of NNMT-expressing cancer-associated fibroblasts

Abstract Nicotinamide N-methyltransferase (NNMT) is highly expressed in the stroma of several malignancies and has been shown to drive the transformation of resting fibroblasts into cancer-associated fibroblasts (CAFs) through epigenetic changes. Given that CAFs can promote immunosuppression in cancer, the aim of our study was to investigate the effect of NNMT-expressing CAFs on the tumor-immune environment. Using a co-culture system of normal fibroblasts and activated PBMCs, we found that IFN-γ produced by PBMCs upregulates NNMT expression in fibroblasts. We confirmed this mechanism in vivo in IFN-γ knockout mice and identified T cells as the main source of IFN-γ in the tumor. Gene expression and protein analysis showed that upregulation of NNMT in CAFs induces the secretion of the chemokine CXCL1, a critical chemoattractant for immunosuppressive myeloid-derived suppressor cells (MDSCs). Upregulation of NNMT induces CXCL1 secretion directly through promoter hypomethylation, and in vitro migration assays show that NNMT-expressing CAFs recruit high numbers of MDSCs. Using spectral flow cytometry, we analyzed the tumor-immune cell infiltration in whole-body NNMT-knockout mice and discovered that NNMT knockout of the stroma significantly reduced the abundance of MDSCs and increased the number of functional CD8+ T cells. Increased T cell cytotoxicity was associated with a significant reduction in tumor burden in the syngeneic ID8 ovarian and MC38 colon cancer models. These findings were confirmed after adoptive transfer of NNMT-wildtype immune cells into irradiated whole-body NNMT-knockout mice. Moreover, in scRNA-seq data of various human malignancies, we found a strong correlation between NNMT and CXCL1 expression in CAFs. In summary, our results support a model in which cancer cells induce IFN-γ secretion by T-cells, thereby upregulating NNMT expression in fibroblasts, leading to CXCL1 secretion. CXCL1 secreted by CAFs recruits MDSCs to the tumor, which in turn suppress the anti-tumor T cell response. Citation Format: Janna Heide, Andras Piffko, Agnes J. Bilecz, Ethan A. Teich, Lisa Schweizer, Sayed R. Alhunayan, Kaiting Yang, Ernst Lengyel. Immunoregulatory effects of NNMT-expressing cancer-associated fibroblasts. [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 4462.

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.

Fibroblast Activation Protein Triggers Release of Drug Payload from Non-internalizing Small Molecule Drug Conjugates in Solid Tumors.

Small molecule drug conjugates (SMDC) are modular anticancer prodrugs that include a tumor-targeting small organic ligand, a cleavable linker, and a potent cytotoxic agent. Most of the SMDC products that have been developed for clinical applications target internalizing tumor-associated antigens on the surface of tumor cells. We have recently described a novel non-internalizing small organic ligand (named OncoFAP) of fibroblast activation protein (FAP), a tumor-associated antigen highly expressed in the stroma of most solid human malignancies. In this article, we describe a new series of OncoFAP-Drug derivatives based on monomethyl auristatin E (MMAE; a potent cytotoxic tubulin poison) and dipeptide linkers that are selectively cleaved by FAP in the tumor microenvironment. The tumor-targeting potential of OncoFAP was confirmed in patients with cancer using nuclear medicine procedures. We used mass spectrometry methodologies to quantify the amount of prodrug delivered to tumors and normal organs, as well as the efficiency of the drug release process. Linkers previously exploited for anticancer drug conjugates were used as benchmark. We identified OncoFAP-Gly-Pro-MMAE as the best performing SMDC, which has now been prioritized for further clinical development. OncoFAP-Gly-Pro-MMAE selectively delivered more than 10% injected dose per gram of MMAE to FAP-positive tumors, with a tumor-to-kidney ratio of 16:1 at 24 hours post-injection. The FAP-specific drug conjugates described in this article promise to be efficacious for the targeting of human malignancies. The extracellular release of potent anticancer payloads mediates durable complete remission in difficult-to-treat animal models of cancer.

A Recurrent Breast Carcinosarcoma in a Young Woman, a Case Study

Carcinosarcoma is a biphasic tumor comprised of both malignant epithelium and malignant stroma. Compared to other types of breast cancer, this subtype is clinically aggressive and has a poor prognosis. Luckily, it is extremely rare. Carcinosarcomas of the breast presents a challenge, both diagnostically and therapeutically, due to the lack of systemic guidelines in management. Here, we present a case of a 37- year-old woman affected by carcinosarcoma of the right breast. We discuss the clinical presentation, the histopathology findings, and the imaging characteristics of the tumor, the diagnostic approach, and the treatment plan, as well as a short literature review.

Stromal fibroblasts regulate microvascular-like network architecture in a bioengineered breast tumour angiogenesis model

The plasticity of the tumour microenvironment is a key contributor to cancer development and progression. Here, we present a bioengineered breast tumour angiogenesis model comprised of mammary derived epithelial, endothelial and fibroblast cells, to dissect the mechanisms of cancer-associated fibroblasts (CAFs) on microvascular-like network formation and epithelial spheroid morphology. Primary patient-derived mammary endothelial cells, normal breast fibroblasts (NBF, patient matched) and CAFs were cultured within three-dimensional (3D) semi-synthetic hydrogels where CAFs promoted an increase in the density and morphology of the microvascular-like network. The mammary microenvironment also increased the number of MCF-10a epithelial spheroids when compared with a non-mammary microenvironment, and a malignant mammary microenvironment resulted in further morphological differences in the epithelial spheroids. The morphological changes observed following interactions between breast CAFs and endothelial cells, highlight the plasticity of the malignant stroma in tumour vascularisation. Our in vitro bioengineered breast cancer microenvironment provides a robust model to study cell-cell and cell-matrix interactions.Statement of SignificanceIn recent years there has been an increase in the sophistication of 3D culture models, however less attention has been paid to the cell source utilised. In this study, we describe the influence of a normal and malignant stromal microenvironment on vessel-like behaviour in a 3D model. Using a semi-synthetic hydrogel, we studied the effects of mammary-derived cancer-associated fibroblasts and normal fibroblasts on human umbilical vein endothelial cells or human mammary microvascular endothelial cells. An increase in vessel-like network and epithelial cell density was seen in a mammary versus non-mammary microenvironment. This study highlights the importance of using tissue-specific endothelial cells in cancer research and demonstrates the microenvironmental impact of fibroblasts on endothelial and epithelial growth and morphology.

Whole-Genome Sequencing and Target Validation Analysis of Müllerian Adenosarcoma: A Tumor With Complex but Specific Genetic Alterations.

Mullerian adenosarcoma (MAS) is a biphasic tumor with malignant stroma. It is most commonly of endometrial origin but occasionally originates in the cervix, ovary, or other pelvic/peritoneal sites. The typical MAS is low grade with an indolent clinical course; however, tumors with sarcomatous overgrowth (SO) or a high-grade sarcoma tend to be aggressive. Tumor etiology is largely unknown. To better understand the global genome alterations and gene mutations in MAS, whole-genome sequencing (WGS) and target validation analysis were performed. MAS showed remarkable chromosome (chr) copy number variation (CNV), specifically, gains in chr 1q, 5p, 12p, 12q, and 17q and losses in chr 3p, 3q, 9p, and 11q. Gain of chr 12q13-15 was present in 50% of cases. The selected gene products in gain regions were upregulated as measured by immunohistochemistry. HMGA2 overexpression was significantly correlated with SO. While the structural variation (SV) rate was relatively low overall, a disproportionally high rate of break-ends at chr 7 was noted involving 6 in-frame rearrangement fusion genes. Among 40 frequently mutated genes detected by WGS and validated in 29 MAS by next generation sequencing (NGS), KMT2C, and BCOR were frequently seen in MAS both with and without SO, while MAGEC1 and KDM6B were strongly associated with SO. Overall, a higher rate of frequently mutated genes was found in MAS with SO (33%) than MAS without (11%). This study uncovers the complex and specific genetic alterations in this malignancy. The findings provide a tool for future investigation of these molecular changes in tumorigenesis and target therapies.

Fibroblastic Subtype has a Favourable Prognosis in Appendicular Osteosarcoma of Dogs

Osteosarcoma (OS) is an aggressive malignant bone neoplasm that occurs mostly in the appendicular skeleton of dogs and people. OS is classified based on the presence of malignant stroma and the formation of extracellular matrix into osteoblastic, chondroblastic and fibroblastic forms. This study investigated the correlation between the three histological subtypes of canine OS and clinical outcome. Additionally, we examined whether there was any difference in the immunolabelling of desmin, S100 and neuron-specific enolase (NSE) between the three histological subtypes. Formalin-fixed and paraffin wax-embedded tissues from 87 dogs with primary OS were available for this study. The survival times were correlated with appendicular OS subtypes in dogs that were treated surgically, received adjuvant chemotherapy and had no pulmonary metastasis at the time of diagnosis. Dogs with an appendicular fibroblastic OS had significantly prolonged mean average survival times (546±105 days) in comparison with dogs having appendicular osteoblastic (257±48 days) or appendicular chondroblastic (170±28 days) OS (P=0.003, Log Rank). The results also revealed that the appendicular chondroblastic subtype is a significant indicator for poor prognosis in dogs compared with the fibroblastic or osteoblastic subtypes (P=0.006, Cox regression). Moreover, the findings indicated that there was no significant correlation between the localization of desmin, NSE or S100 and histological subtypes. Importantly, dogs with appendicular fibroblastic OS were found to have a better prognosis when compared with dogs with other subtypes. This may suggest that histological subtypes of appendicular OS have diverse behaviour and could be used to categorize patients for risk-based assessment.

A paracrine activin A–mDia2 axis promotes squamous carcinogenesis via fibroblast reprogramming

Cancer‐associated fibroblasts (CAFs) are key regulators of tumorigenesis and promising targets for next‐generation therapies. We discovered that cancer cell‐derived activin A reprograms fibroblasts into pro‐tumorigenic CAFs. Mechanistically, this occurs via Smad2‐mediated transcriptional regulation of the formin mDia2, which directly promotes filopodia formation and cell migration. mDia2 also induces expression of CAF marker genes through prevention of p53 nuclear accumulation, resulting in the production of a pro‐tumorigenic matrisome and secretome. The translational relevance of this finding is reflected by activin A overexpression in tumor cells and of mDia2 in the stroma of skin cancer and other malignancies and the correlation of high activin A/mDia2 levels with poor patient survival. Blockade of this signaling axis using inhibitors of activin, activin receptors, or mDia2 suppressed cancer cell malignancy and squamous carcinogenesis in 3D organotypic cultures, ex vivo, and in vivo, providing a rationale for pharmacological inhibition of activin A‐mDia2 signaling in stratified cancer patients.

Struma Ovarii With the Coexistence of Hashimoto’s Thyroiditis: A Case Report

Background: Struma ovarii (SO) is a rare phenomenon. In addition, it can be identified from the histological assessment and may show the characteristics of Hashimoto’s thyroiditis in rare cases. In several cases, malignant stroma ovarii is found to produce hyperthyroidism while very few cases are reported with Hashimoto’s thyroiditis. The present study reported SO co-incident with Hashimoto’s thyroiditis. It should be mentioned that accurate monitoring of any signs of hypothyroidism is highly important after the surgery. Case Report: A 21-year-old patient with oligomenorrhea, hypogastric pain for the last year, dyspareunia and dysmenorrhea with a right adnexal cystic focus, and a bright echogenic focus referred to Al-Zahra hospital, Rasht. Histopathologic examination was compatible with the diagnosis of mature cystic teratoma containing SO co-incident with Hashimoto’s thyroiditis while the patient was in a good general appearance 2 days after the surgery. Regarding the subclinical hypothyroidism and due to her willingness to conceive, the clinician administered levothyroxine and thus the patient was in a stable state within 6 months. Conclusion: In general, it is recommended to consider SO in women with ovarian mass and impaired thyroid function.

Pulmonary Blastoma in an adult male

Pulmonary blastoma is one of the rare lung tumors and is considered to be distinct from other lung tumors by its pathological features, clinical course and prognosis [1]. Classic pulmonary blastoma is composed of both malignant mesenchymal stroma and epithelial components resembling embryonic lung tissue. Surgery is the standard treatment and the efficacy of adjuvant chemotherapy and radiotherapy has not yet been established [2]. Case Report Our patient was admitted and managed at Abassia Pulmonary Hospital, Ministry of Health, Cairo Governorate, Egypt. A 37-year-old Egyptian male presented to our hospital after repeated attacks of blood tinged sputum. The first attack dated about 6 months before admission. The patient had progressive shortness of breath over a period of two years. The patient was a smoker of one pack of cigarettes per day for more than 15 years. There was no significant past history nor family history. After admission to the Chest Medicine Department at Abbasia Pulmonary Hospital, routine basic investigations were done including complete blood picture with differential count, fasting blood sugar and 2 hours after meal, liver function tests, renal function tests, and coagulation profile. All investigations were within normal.

Migration dynamics of ovarian epithelial cells on micro-fabricated image-based models of normal and malignant stroma

A profound remodeling of the collagen in the extracellular matrix (ECM) occurs in human ovarian cancer but it is unknown how this affects migration dynamics and ultimately tumor growth. Here, we investigate the influence of collagen morphology on ovarian cell migration through the use of second harmonic generation (SHG) image-based models of ovarian tumors. The scaffolds are fabricated by multiphoton excited (MPE) polymerization, where the process is akin to 3D printing except it achieves much greater resolution (∼0.5 µm) and utilizes collagen and collagen analogs. We used this technique to create scaffolds with complex 3D submicron features representing the collagen fiber morphology in normal stroma, high risk stroma, benign tumors, and high grade ovarian tumors. We found the highly aligned malignant stromal structure promoted enhanced motility and also increased cell and f-Actin alignment relative to the other tissues. However, using models based on fiber crimping characteristics, we found cells seeded on linear fibers based on normal stromal models yielded the highest degree of alignment but least motility. These results show that both the fiber properties themselves and as well as their overall alignment govern the resulting migration dynamics. These models cannot be synthesized by other conventional fabrication methods and we suggest the MPE image-based fabrication method will enable a variety of studies in cancer biology. Statement of significanceThe extracellular matrix collagen in ovarian cancer is highly remodeled but the consequences on cell function remain unknown. It is important to understand the operative cell matrix interactions, as this could lead to better prognostics and better prediction of therapeutic efficacy. We probe migration dynamics using high resolution (∼0.5 µm) multiphoton excited fabrication to synthesize scaffolds whose designs are derived directly from Second Harmonic Generation microscope images of the collagen in normal ovarian tissues as well as benign and malignant tumors. Collectively our results show the importance of the matrix morphology (fiber shape and alignment) on driving cell motility, cell shape and f-Actin alignment. These collagen-based models have complex fiber morphology and cannot be created by conventional fabrication technologies.

CD10 expression by stromal cells in carcinoma of breast and its correlation with ER, PR, HER2neu and Ki67-A tissue microarray study in a tertiary care hospital

Introduction: CD10 is a metalloproteinase (Zinc dependent) which is expressed in stroma of various epithelial malignancies. It is associated with biological aggressiveness of the tumor. Till now very few studies has been undertaken correlating CD10 with other prognostic markers like lymphnode status, tumor grade, stage, ER, PR, HER2-neu and ki67 in breast carcinoma. Aim: To see the CD10 expression in breast carcinoma and correlate it with ER, PR, HER2 neu and ki67. Materials and Methods: 55 cases of carcinoma breast were diagnosed on histology. Tissue microarray blocks were prepared and Immunohistochemistry was performed for ER, PR, HER2neu, Ki67 and CD10. Result: 32(58%) cases are CD10 positive and 23 (42%) cases are CD10 negative. Out of this 32 positive cases, 12 (22%) cases are weak positive and 20 (36%) cases are strong positive. CD10 is positively correlated with tumor grade.CD10 is negatively correlated with ER and PR status which is not statistically significant and no correlation is found between CD10 and HER2-neu. A positive correlation is seen between CD10 and ki67, but it is not statistically significant. Conclusion: CD10 expression is positively correlated with Ki67 and increasing tumor grade and whereas inversely correlated with ER and PR status. No correlation is seen between CD10 with lymph node status and HER2-neu. Keywords: Breast carcinoma, Histomorphology, IHC, Tissue microarray.

Lymphocytes in Peritumoral Stroma: Evaluation in Epithelial Ovarian Neoplasms

ABSTRACTBackground: Ovarian cancer is a heterogeneous disease, where chronic inflammation is one of the central mechanisms of its pathogenesis. The objectives of the study were to evaluate the expression of CD3, CD4, CD8 and CD20 in the peritumoral stroma of benign and malignant ovarian epithelial neoplasms and to relate them to prognostic factors in ovarian cancer.Methods: We evaluated 77 patients (40 benign epithelial ovarian neoplasms and 37 malignant epithelial ovarian neoplasms). Immunohistochemistry study for cytokines (CD3, CD4, CD8 and CD20) was performed. The evaluation of prognostic factors was performed using the Fisher’s exact test. The significance level was less than 0.05.Results: A higher CD3 expression was found in the stroma of ovarian malignancies compared benign neoplasms, and greater expression of CD4 cells in the stroma of benign neoplasms compared to ovarian cancer. There was a greater expression of CD8 cells in the stromal ovarian malignancies with molecular type II compared to type I. In the evaluation of lymph node metastases, the absence of immuno-labelling of CD20 cells was associated with the absence of lymph node metastases.Conclusion: The immune system plays a multifaceted role and can promote or inhibit tumor growth in different contexts.

Abstract 3967: Comparison of neoadjuvant FOLFIRINOX alone vs FOLFIRINOX + stereotactic body radiation as immune-modulators of the pancreatic adenocarcinoma microenvironment

Abstract Pancreatic ductal adenocarcinoma (PDAC) has dismal five-year survival (<9%). We examined the impact of neoadjuvant FOLFIRINOX alone or in combination with stereotactic body radiation (SBRT) on biomarkers in the PDAC tumor microenvironment (TME). We hypothesize conventional therapies may unmask novel targets in the TME that can be leveraged to enhance the efficacy of immunotherapy in PDAC. We conducted a pilot study using FFPE-tumor sections from PDAC patients who underwent upfront surgical resection (resection-only) or who received neoadjuvant FOLFIRINOX or FOLFIRINOX + SBRT (FOX or FOX+S, respectively) prior to resection (n=6/group). Average time (weeks) from end of neoadjuvant therapy - surgery was 6.6 ± 2.9 (FOX) or 7.0 ± 1.2 (FOX+S). Using the NanoString GeoMX platform to conduct multiplexed analysis of protein targets (~30 analytes) in spatially distinct regions of tumor tissue, we analyzed individual regions in each tumor that were enriched for malignant cells (Pan-Cytokeratin+), stroma (SMA+) or immune cells (CD45+). Across all tumor regions, FOX treatment was associated with increased CD14, CD56, PD-L1, phosphorylated (p-)STAT3, p-AKT, and PTEN compared to resection-only. In contrast, in FOX+S treated patients none of these were elevated in comparison to resection-only, and PTEN was significantly lower. Additionally, CD3, CD4, and CD8 expression—which did not differ between resection-only and FOX, were all significantly lower in FOX+S treated patients. Similar effects were observed in CD45-enriched regions. Whereas FOX treatment was associated with increased CD14, PD-L1, p-STAT3, p-AKT, PTEN, B7-H3, GZMB and β-catenin compared to resection-only, none of these were increased in FOX+S, while PTEN was again significantly decreased. Moreover, CD3 and CD4 expression were also significantly decreased in FOX+S. In tumor-rich regions, we found increased CD3, CD44, CD45RO, and CD56 in FOX-treated tumors as compared to resection-only. However, there was no difference in these markers when comparing resection-only and FOX+S. In addition, CD4 expression was lower in FOX+S samples while FOXP3 expression was unchanged, suggesting a relative enrichment of regulatory T cells. Finally, in αSMA-rich regions (stromal), FOX treatment was associated with increased p-STAT3 and significantly decreased CD4 and VISTA expression. FOX+S exhibited no such increase in p-STAT3 and further significant decreases in CD4 and VISTA expression, while also being associated with significantly lower CD3 and CD8 expression. This data provide insight into the immunological effects of standard of care neoadjuvant therapy for resectable/borderline-resectable PDAC. This work provides data to guide strategic new combination therapies for pancreatic cancer. Citation Format: Matthew R. Farren, Walid Shaib, Mohammad Zaidi, Layal Sayegh, David Kooby, Shishir Maithel, Alyssa Krasinskas, Olatunji Alese, Juan Sarmiento, Bassel El-Rayes, Gregory B. Lesinski. Comparison of neoadjuvant FOLFIRINOX alone vs FOLFIRINOX + stereotactic body radiation as immune-modulators of the pancreatic adenocarcinoma microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3967.

Hypoxia as a signal for prison breakout in cancer.

We discuss recent discoveries in hypoxic cellular pathophysiology and explore the interplay between hypoxic malignant cells and other stromal elements. This review will provide an update on the effects of hypoxia on cancer outcomes and therapeutic resistance. Hypoxia has been discovered to be a key driver for tumor progression, both because of impacts on tumor cells and separately on the wider tumor microenvironment. The latter effects occur via epithelial mesenchymal transition, autophagy and metabolic switching. Through epithelial mesenchymal transition, hypoxia both drives metastasis and renders key target tissues receptive to metastasis. Autophagy is a double-edged sword which requires greater understanding to ascertain when it is a threat. Metabolic switching allows tumor cells to access hypoxic survival mechanisms even under normoxic conditions.Every element of the malignant stroma contributes to hypoxia-driven progression. Exosomal transfer of molecules from hypoxic tumor cells to target stromal cell types and the importance of microRNAs in intercellular communication have emerged as key themes.Antiangiogenic resistance can be caused by hypoxia-driven vasculogenic mimicry. Beyond this, hypoxia contributes to resistance to virtually all oncological treatment modalities. Recent advances have moved us closer to being able to exploit hypoxic mechanisms to overcome hypoxia-driven progression and therapy failure.

Expression of chondroitin sulfotransferases (CHST3,7,11,15) and chondroitin sulfatases in normal and malignant prostate stroma and epithelium

Previous work demonstrated marked decline in arylsulfatase B (ARSB; N‐acetylgalactosamine‐4‐sulfatase) in malignant prostate tissues by immunohistochemistry, activity assay, and mRNA expression. In contrast, activity of galactosamine‐N‐acetyl‐6‐sulfatase (GALNS; N‐acetylgalactosamine‐6‐sulfatase) was significantly increased in malignant prostate tissues. These findings were associated with marked increase in chondroitin 4‐sulfate (C4S), decline in chondroitin 6‐sulfate (C6S), and increased C4S:C6S ratio in the malignant tissues. To further evaluate the chondroitin sulfation, mRNA expression of chondroitin sulfotransferases and chondroitin sulfatases was detected in malignant and normal prostate stromal and epithelial tissues obtained by laser capture microdissection (LCMD) of prostate tissues obtained from the Biorepository of the University of Illinois at Chicago. Primers were identified using Primer3, and QPCR was used to determine expression levels. Confirmation of epithelial vs. stromal content was confirmed by comparative expression of vimentin and E‐cadherin. ARSB expression was similar in the control and malignant stromal tissue and more than two‐fold higher than in the normal epithelial tissue. ARSB expression was reduced by over 50% in the malignant epithelium compared to normal epithelium. In contrast, GALNS expression was over 50% less in the stromal tissues than in the epithelium, and was increased almost two‐fold in the malignant vs. normal prostate epithelium. The expression of CHST15, which adds a 6‐sulfate group to C4S, was increased over four‐fold in the malignant prostate epithelium, and significantly reduced in both normal and malignant stromal tissue. Expression of the 6‐O sulfotransferases CHST3 and CHST7 was also determined. Normal and malignant stromal CHST3 was about 50% the level in the normal and malignant epithelium. CHST7 was slightly less in the malignant epithelium, compared to the normal epithelium and the normal and malignant stroma. The 4‐O sulfotransferase CHST11 was reduced about 50% in the malignant epithelium, compared to normal epithelium, and increased about 80% in the normal and malignant stroma. These findings suggest that increased expression of CHST15 and GALNS in the epithelium may lead to enhanced production of C4S. This is perhaps compensatory, due to decline in CHST11. However, in association with decline in ARSB, these effects lead to increased epithelial C4S. Since increased C4S has been associated with reduced activity of SHP2, the tyrosine‐protein phosphatase non‐receptor type 11 (PTPN11) and increased availability of galectin‐3, these changes have important consequences for cell signaling, growth, and metabolism and for stromal‐epithelial interactions.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Imaging and Characterization of Macrophage Distribution in Mouse Models of Human Prostate Cancer.

Prostate carcinoma consists of tumor epithelium and malignant stroma. Until recently, diagnostic and therapeutic efforts have focused exclusively on targeting characteristics of the tumor epithelium, ignoring opportunities to target inflammatory infiltrate and extracellular matrix components. Prostate tumors are rich in tumor-associated macrophages (TAMs), which can be either of the cytotoxic M1 or protumorigenic M2 phenotype. We have quantified the proportion of each in seven common human prostate tumor lines grown subcutaneously in athymic nude mice and have imaged macrophage densities in vivo in xenografts derived from these lines. A panel of seven human prostate cancer xenografts was generated in intact male athymic nude mice reflecting variable expression of the androgen receptor (AR) and prostate-specific membrane antigen (PSMA). Mice were imaged ex vivo using near-infrared fluorescence (NIRF) imaging for PSMA expression and total macrophage densities to enable direct comparison between the two. Tumors were harvested for sectioning and additional staining to delineate M1 and M2 phenotype along with vascular density. Macrophage polarization analysis of sections revealed that all xenografts were > 94% M2 phenotype, and the few M1-polarized macrophages present were confined to the periphery. Xenografts displaying the fastest growth were associated with the highest densities of macrophages while the slowest growing tumors were characterized by focal, tumor-infiltrating macrophage densities. Xenograft sections displayed a strong positive spatial relationship between macrophages, vasculature, and PSMA expression. Prostate TAM disposition can be imaged ex vivo and is associated with growth characteristics of a variety of tumor subtypes regardless of PSMA or AR expression.

Hyaluronan, Cancer-Associated Fibroblasts and the Tumor Microenvironment in Malignant Progression.

This review summarizes the roles of CAFs in forming a “cancerized” fibrotic stroma favorable to tumor initiation and dissemination, in particular highlighting the functions of the extracellular matrix component hyaluronan (HA) in these processes. The structural complexity of the tumor and its host microenvironment is now well appreciated to be an important contributing factor to malignant progression and resistance-to-therapy. There are multiple components of this complexity, which include an extensive remodeling of the extracellular matrix (ECM) and associated biomechanical changes in tumor stroma. Tumor stroma is often fibrotic and rich in fibrillar type I collagen and hyaluronan (HA). Cancer-associated fibroblasts (CAFs) are a major source of this fibrotic ECM. CAFs organize collagen fibrils and these biomechanical alterations provide highways for invading carcinoma cells either under the guidance of CAFs or following their epithelial to mesenchymal transition (EMT). The increased HA metabolism of a tumor microenvironment instructs carcinoma initiation and dissemination by performing multiple functions. The key effects of HA reviewed here are its role in activating CAFs in pre-malignant and malignant stroma, and facilitating invasion by promoting motility of both CAFs and tumor cells, thus facilitating their invasion. Circulating CAFs (cCAFs) also form heterotypic clusters with circulating tumor cells (CTC), which are considered to be pre-cursors of metastatic colonies. cCAFs are likely required for extravasation of tumors cells and to form a metastatic niche suitable for new tumor colony growth. Therapeutic interventions designed to target both HA and CAFs in order to limit tumor spread and increase response to current therapies are discussed.