(15)O-Water PET Study of the Effect of Imatinib, a Selective Platelet-Derived Growth Factor Receptor Inhibitor, Versus Anakinra, an IL-1R Antagonist, on Water-Perfusable Tissue Fraction in Colorectal Cancer Metastases

Whole-body parametric mapping of tumour perfusion in metastatic prostate cancer using long axial field-of-view [15O]H2O PET

PURPOSE

Tumour perfusion is a nutrient-agnostic biomarker for cancer metabolic rate. Use of tumour perfusion for cancer growth assessment has been limited by complicated image acquisition, image analysis and limited field-of-view scanners. Long axial field-of-view (LAFOV) PET scan using [15O]H2O, allows quantitative assessment of whole-body tumour perfusion. We created a tool for automated creation of quantitative parametric whole-body tumour perfusion images in metastatic cancer.

METHODS

Ten metastatic prostate cancer patients underwent dynamic LAFOV [15O]H2O PET (Siemens, Quadra) followed by [18F]PSMA-1007 PET. Perfusion was measured as [15O]H2O K1 (mL/min/mL) with a single-tissue compartment model and an automatically captured cardiac image-derived input function. Parametric perfusion images were automatically calculated using the basis-function method with initial voxel-wise delay estimation and a leading-edge approach. Subsequently, perfusion of volumes-of-interest (VOI) can be directly extracted from the parametric images. We used a [18F]PSMA-1007 SUV 4 fixed threshold for tumour delineation and transferred these VOIs to the perfusion map.

RESULTS

For 8 primary tumours, 64 lymph node metastases, and 85 bone metastases, median tumour perfusion were 0.19 (0.15-0.27) mL/min/mL, 0.16 (0.13-0.27) mL/min/mL, and 0.26 (0.21-0.39), respectively. The correlation between calculated perfusion from time-activity-curves and parametric images was excellent (r = 0.99, p < 0.0001).

CONCLUSION

LAFOV PET imaging using [15O]H2O enables truly quantitative parametric images of whole-body tumour perfusion, a potential biomarker for guiding personalized treatment and monitoring treatment response.

PET Imaging of Metabolism, Perfusion, and Hypoxia: FDG and Beyond

ABSTRACT

Imaging glucose metabolism with [18F]fluorodeoxyglucose positron emission tomography has transformed the diagnostic and treatment algorithms of numerous malignancies in clinical practice. The cancer phenotype, though, extends beyond dysregulation of this single pathway. Reprogramming of other pathways of metabolism, as well as altered perfusion and hypoxia, also typifies malignancy. These features provide other opportunities for imaging that have been developed and advanced into humans. In this review, we discuss imaging metabolism, perfusion, and hypoxia in cancer, focusing on the underlying biology to provide context. We conclude by highlighting the ability to image multiple facets of biology to better characterize cancer and guide targeted treatment.

Colorectal cancer subtyping and prognostic model construction based on interleukin-related genes

Members of the interleukin (IL) family are closely linked to cancer development and progression. However, research on the prognosis of colorectal cancer (CRC) related to IL is still lacking. This study investigated new CRC prognostic markers and offered new insights for CRC prognosis and treatment. CRC-related data and IL gene data were collected from public databases. Sample clustering was done with the NMF package to divide samples into different subtypes. Differential, enrichment, survival, and immune analyses were conducted on subtypes. A prognostic model was constructed using regression analysis. Drug sensitivity analysis was performed using GDSC database. Western blot analysis was performed to assess the effect of IL-7 on the JAK/STAT signaling pathway. Flow cytometry was used to examine the impact of IL-7 on CD8+ T cell apoptosis. Two CRC subtypes based on IL-associated genes were obtained. Cluster 1 had a higher survival rate than cluster 2, and they showed differences in some immune levels. The two clusters were mainly enriched in the JAK-STAT signaling pathway, T helper 17 cell differentiation, and the IL-17 signaling pathway. An 11-gene signature was built, and risk score was an independent prognosticator for CRC. The low-risk group showed a higher sensitivity to nine common targeted anticancer drugs. Western blot and flow cytometry results demonstrated that IL-7 could phosphorylate STAT5 and promote survival of CD8+ T cells. In conclusion, this study divided CRC samples into two IL-associated subtypes and obtained an 11-gene signature. In addition, targeted drugs that may improve the prognosis of patients with CRC were identified. These findings are of paramount importance for patient prognosis and CRC treatment.NEW & NOTEWORTHY We identified two clusters with significant survival differences in colorectal cancer (CRC) based on interleukin-related genes, constructed an 11-gene risk score model that can independently predict the prognosis of CRC, and explored some targeted drugs that may improve the prognosis of patients with CRC. The results of this study have important implications for the prognosis and treatment of CRC.

Improvement in the estimation of perfusable tissue fraction and myocardial flow reserve in the ischemic myocardial lesions using ECG-gated dynamic myocardial PET with 15O-water

OBJECTIVE

Perfusable tissue fraction (PTF) and myocardial flow reserve (MFR) from 15O-water dynamic positron emission tomography (PET) are parameters of myocardial viability. However, myocardial motion causes errors in these values. We aimed to develop accurate estimation of PTF and MFR in ischemic lesions using an electro-cardiogram (ECG)-gated dynamic myocardial PET with 15O-water.

METHODS

Twenty-seven patients with ischemic heart disease were enrolled. All patients underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). List mode 3D PET data and ECG signals were acquired using Philips Gemini TF64 instrument. For each scan, 500 MBq of 15O-water was infused slowly for 2 min, and the dynamic data were scanned for 6 min. Both non-gated dynamic images and ECG-gated diastolic dynamic images were reconstructed. On the myocardial PET images of each patient, the entire myocardial region of interest (ROI) was set and divided into 17 segments. Myocardial blood flow in the resting state (rest MBF), hyperemic state (stress MBF), PTF, and MFR in each segment were estimated from both non-gated and ECG-gated dynamic PET images. Coronary arteriograms were obtained for all patients. In total, 128 normal segments without stenosis and 50 ischemic segments with > 90% stenosis were evaluated.

RESULTS

In the ischemic myocardial segments, the PTF with ECG-gated PET was estimated as significantly lower than that with non-gated PET (0.63 ± 0.09 vs. 0.72 ± 0.08 [mL/mL], p < 0.001). The ECG-gated PET estimated a significantly lower PTF in the ischemic segments than in the normal segments (0.63 ± 0.09 vs. 0.67 ± 0.07 [mL/mL], p < 0.01). In the normal segments, the ECG-gated PET detected no significant difference in MFR compared with those from the non-gated PET (2.15 ± 0.76 vs. 2.24 ± 0.79, p = 0.28). However, in the ischemic myocardial segments, the MFR with ECG-gated PET was estimated as significantly lower than that with the non-gated PET (1.23 ± 0.29 vs. 1.69 ± 0.71, p < 0.001). The ECG-gated PET presented a significantly higher inter-observer reproducibility of PTF and rest MBF than the non-gated PET (p < 0.01). Neither stress MBF nor MFR yielded significant differences in inter-observer reproducibility between the ECG-gated and non-gated PET.

CONCLUSIONS

The ECG-gated dynamic 15O-water PET suppressed the myocardial motion effect and resulted in a lower PTF and MFR in ischemic myocardial lesions than the non-gated PET. The ECG-gated PET seemed to be better than the conventional non-gated dynamic PET for the detection of ischemic myocardial lesion.

[15O]H2O PET: Potential or Essential for Molecular Imaging?

Imaging water pathways in the human body provides an excellent way of measuring accurately the blood flow directed to different organs. This makes it a powerful diagnostic tool for a wide range of diseases that are related to perfusion and oxygenation. Although water PET has a long history, its true potential has not made it into regular clinical practice. The article highlights the potential of water PET in molecular imaging and suggests its prospective role in becoming an essential tool for the 21st century precision medicine in different domains ranging from preclinical to clinical research and practice. The recent technical advances in high-sensitivity PET imaging can play a key accelerating role in empowering this technique, though there are still several challenges to overcome.

Interleukins (Cytokines) as Biomarkers in Colorectal Cancer: Progression, Detection, and Monitoring

Cancer is the primary cause of death in economically developed countries and the second leading cause in developing countries. Colorectal cancer (CRC) is the third most common cause of cancer-related deaths worldwide. Risk factors for CRC include obesity, a diet low in fruits and vegetables, physical inactivity, and smoking. CRC has a poor prognosis, and there is a critical need for new diagnostic and prognostic biomarkers to reduce related deaths. Recently, studies have focused more on molecular testing to guide targeted treatments for CRC patients. The most crucial feature of activated immune cells is the production and release of growth factors and cytokines that modulate the inflammatory conditions in tumor tissues. The cytokine network is valuable for the prognosis and pathogenesis of colorectal cancer as they can aid in the cost-effective and non-invasive detection of cancer. A large number of interleukins (IL) released by the immune system at various stages of CRC can act as "biomarkers". They play diverse functions in colorectal cancer, and include IL-4, IL-6, IL-8, IL-11, IL-17A, IL-22, IL-23, IL-33, TNF, TGF-β, and vascular endothelial growth factor (VEGF), which are pro-tumorigenic genes. However, there are an inadequate number of studies in this area considering its correlation with cytokine profiles that are clinically useful in diagnosing cancer. A better understanding of cytokine levels to establish diagnostic pathways entails an understanding of cytokine interactions and the regulation of their various biochemical signaling pathways in healthy individuals. This review provides a comprehensive summary of some interleukins as immunological biomarkers of CRC.

Role of Interleukin-1 in the pathogenesis of colorectal cancer: A brief look at anakinra therapy

Colorectal cancer (CRC) is known as one of the deadliest and most common cancers globally and causes nearly one million cancer deaths yearly. Like many malignancies, the immune system and its components play a crucial role in the pathogenesis of CRC. As multifunction mediators of the immune system, cytokines are involved in several inflammatory and anti-inflammatory responses. Interleukin-1 (IL-1) belongs to a family of 11 members and is involved in inflammatory responses. Beyond its biological role as a mediator of innate immune responses, it is also seen in chronic stress and inflammation and numerous pathological states. The role of IL-1 in malignancies can also be very significant because it has recently been shown that this cytokine can also be secreted from tumor cells and induce the recruitment of myeloid-derived immunosuppressive cells. As a result, the tumor microenvironment (TME) is affected and, despite being inflammatory, causes the onset and progression of tumor cells. Since surgery and chemotherapy are the first choices to treat patients with cancer, especially CRC, it is usually not well-prognosed, particularly in patients with metastatic lesions CRC. Therefore, targeted therapy may prolong the overall survival of CRC patients. Furthermore, evidence shows that anakinra has had satisfactory results in treating CRC. Therefore, this review summarized the role of IL-1 in the pathogenesis of CRC as well as immunotherapy based on inhibition of this cytokine in this type of cancer.

Potential synergy between PSMA uptake and tumour blood flow for prediction of human prostate cancer aggressiveness

BACKGROUND

Both prostate-specific membrane antigen (PSMA) uptake and tumour blood flow (TBF) correlate with International Society of Urological Pathology (ISUP) Grade Group (GG) and hence prostate cancer (PCa) aggressiveness. The aim of the present study was to evaluate the potential synergistic benefit of combining the two physiologic parameters for separating significant PCa from insignificant findings.

METHODS

From previous studies of [82Rb]Rb positron emission tomography (PET) TBF in PCa, the 43 patients that underwent clinical [68Ga]Ga-PSMA-11 PET were selected for this retrospective study. Tumours were delineated on [68Ga]Ga-PSMA-11 PET or magnetic resonance imaging. ISUP GG was recorded from 52 lesions.

RESULTS

[68Ga]Ga-PSMA-11 maximum standardized uptake value (SUVmax) and [82Rb]Rb SUVmax correlated moderately with ISUP GG (rho = 0.59 and rho = 0.56, both p < 0.001) and with each other (r = 0.65, p < 0.001). A combined model of [68Ga]Ga-PSMA-11 and [82Rb]Rb SUVmax separated ISUP GG > 2 from ISUP GG 1-2 and benign with an area-under-the-curve of 0.85, 96% sensitivity, 74% specificity, and 95% negative predictive value. The combined model performed significantly better than either tracer alone did (p < 0.001), primarily by reducing false negatives from five or six to one (p ≤ 0.025).

CONCLUSION

PSMA uptake and TBF provide complementary information about tumour aggressiveness. We suggest that a combined analysis of PSMA uptake and TBF could significantly improve the negative predictive value and allow non-invasive separation of significant from insignificant PCa.

The Role of Interleukins in Colorectal Cancer

Despite great progress has been made in treatment strategies, colorectal cancer (CRC) remains the predominant life-threatening malignancy with the feature of high morbidity and mortality. It has been widely acknowledged that the dysfunction of immune system, including aberrantly expressed cytokines, is strongly correlated with the pathogenesis and progression of colorectal cancer. As one of the most well-known cytokines that were discovered centuries ago, interleukins are now uncovering new insights into colorectal cancer therapy. Herein, we divide currently known interleukins into 6 families, including IL-1 family, IL-2 family, IL-6 family, IL-8 family, IL-10 family and IL-17 family. In addition, we comprehensively reviewed the oncogenic or antitumour function of each interleukin involved in CRC pathogenesis and progression by elucidating the underlying mechanisms. Furthermore, by providing interleukins-associated clinical trials, we have further driven the profound prospect of interleukins in the treatment of colorectal cancer.

Repeatability of tumor blood flow quantification with 82Rubidium PET/CT in prostate cancer - a test-retest study

BACKGROUND

Non-invasive tumor blood flow (TBF) quantification is a candidate approach for risk stratification and monitoring of prostate cancer patients. Validation data have recently been published on prostate TBF measurement with the widely used positron emission tomography (PET) flow tracer ⁸²Rubidium (⁸²Rb). However, no test-retest data is available for TBF measurement with ⁸²Rb PET in prostate cancer. Such information is important to determine the potential clinical usefulness of the technique. The aim of the present study was to determine the test-retest repeatability of TBF measurement with both dynamic and static ⁸²Rb PET.

METHODS

We recruited 10 low-to-high-risk prostate cancer patients scheduled for clinical prostate-specific membrane antigen (PSMA) PET/computed tomography (CT) or magnetic resonance imaging. Pelvic and cardiac static and dynamic ⁸²Rb PET/CT were performed at baseline and repeated on a different day within 1 week. In total, 11 primary lesions were analyzed.

RESULTS

For K1, standardized uptake values (SUV)max, SUVmean, and SUVpeak, prostate cancer ⁸²Rb PET TBF has a repeatability of 32%, 51%, 53%, and 58% and an intraclass correlation of 0.98, 0.89, 0.88, and 0.88, respectively.

CONCLUSION

Dynamic ⁸²Rb PET/CT with kinetic modeling measures TBF in prostate cancer with high repeatability, which allows identification of blood flow changes of 32%. Static late-uptake ⁸²Rb PET/CT is inferior, and only intra-individual blood flow changes above 51% can hence be recognized.

HIGH expression of OSM and IL-6 are associated with decreased breast cancer survival: synergistic induction of IL-6 secretion by OSM and IL-1β

Chronic inflammation has been recognized as a risk factor for the development and maintenance of malignant disease. Cytokines such as interleukin-6 (IL-6), oncostatin M (OSM), and interleukin-1 beta (IL-1β) promote the development of both acute and chronic inflammation while promoting in vitro metrics of breast cancer metastasis. However, anti-IL-6 and anti-IL-1β therapeutics have not yielded significant results against solid tumors in clinical trials. Here we show that these three cytokines are interrelated in expression. Using the Curtis TCGA™ dataset, we have determined that there is a correlation between expression levels of OSM, IL-6, and IL-1β and reduced breast cancer patient survival (r = 0.6, p = 2.2 x 10⁻²³). Importantly, we confirm that OSM induces at least a 4-fold increase in IL-6 production from estrogen receptor-negative (ER−) breast cancer cells in a manner that is dependent on STAT3 signaling. Furthermore, OSM induces STAT3 phosphorylation and IL-1β promotes p65 phosphorylation to synergistically induce IL-6 secretion in ER− MDA-MB-231 and to a lesser extent in ER+ MCF7 human breast cancer cells. Induction may be reduced in the ER+ MCF7 cells due to a previously known suppressive interaction between ER and STAT3. Interestingly, we show in MCF7 cells that ER’s interaction with STAT3 is reduced by 50% through both OSM and IL-1β treatment, suggesting a role for ER in mitigating STAT3-mediated inflammatory cascades. Here, we provide a rationale for a breast cancer treatment regime that simultaneously suppresses multiple targets, as these cytokines possess many overlapping functions that increase metastasis and worsen patient survival.

Fibromodulin deficiency reduces collagen structural network but not glycosaminoglycan content in a syngeneic model of colon carcinoma

Tumor barrier function in carcinoma represents a major challenge to treatment and is therefore an attractive target for increasing drug delivery. Variables related to tumor barrier include aberrant blood vessels, high interstitial fluid pressure, and the composition and structure of the extracellular matrix. One of the proteins associated with dense extracellular matrices is fibromodulin, a collagen fibrillogenesis modulator expressed in tumor stroma but scarce in normal loose connective tissues. Here, we investigated the effects of fibromodulin on stroma ECM in a syngeneic murine colon carcinoma model. We show that fibromodulin deficiency decreased collagen fibril thickness but glycosaminoglycan content and composition were unchanged. Furthermore, vascular density, pericyte coverage and macrophage amount were unaffected. Fibromodulin can therefore be a unique effector of dense collagen matrix assembly in tumor stroma and, without affecting other major matrix components or the cellular composition, can function as a main agent in tumor barrier function.

Theranostic Probes for Targeting Tumor Microenvironment: An Overview

Long gone is the time when tumors were thought to be insular masses of cells, residing independently at specific sites in an organ. Now, researchers gradually realize that tumors interact with the extracellular matrix (ECM), blood vessels, connective tissues, and immune cells in their environment, which is now known as the tumor microenvironment (TME). It has been found that the interactions between tumors and their surrounds promote tumor growth, invasion, and metastasis. The dynamics and diversity of TME cause the tumors to be heterogeneous and thus pose a challenge for cancer diagnosis, drug design, and therapy. As TME is significant in enhancing tumor progression, it is vital to identify the different components in the TME such as tumor vasculature, ECM, stromal cells, and the lymphatic system. This review explores how these significant factors in the TME, supply tumors with the required growth factors and signaling molecules to proliferate, invade, and metastasize. We also examine the development of TME-targeted nanotheranostics over the recent years for cancer therapy, diagnosis, and anticancer drug delivery systems. This review further discusses the limitations and future perspective of nanoparticle based theranostics when used in combination with current imaging modalities like Optical Imaging, Magnetic Resonance Imaging (MRI) and Nuclear Imaging (Positron Emission Tomography (PET) and Single Photon Emission Computer Tomography (SPECT)).

The Tyrosine Kinase Inhibitor Imatinib Augments Extracellular Fluid Exchange and Reduces Average Collagen Fibril Diameter in Experimental Carcinoma

A typical obstacle to cancer therapy is the limited distribution of low molecular weight anticancer drugs within the carcinoma tissue. In experimental carcinoma, imatinib (STI571) increases efficacy of synchronized chemotherapy, reduces tumor interstitial fluid pressure, and increases interstitial fluid volume. STI571 also increases the water-perfusable fraction in metastases from human colorectal adenocarcinomas. Because the mechanism(s) behind these effects have not been fully elucidated, we investigated the hypothesis that STI571 alters specific properties of the stromal extracellular matrix. We analyzed STI571-treated human colorectal KAT-4/HT-29 experimental carcinomas, known to have a well-developed stromal compartment, for solute exchange and glycosaminoglycan content, as well as collagen content, structure, and synthesis. MRI of STI571-treated KAT-4/HT-29 experimental carcinomas showed a significantly increased efficacy in dynamic exchanges of solutes between tumor interstitium and blood. This effect was paralleled by a distinct change of the stromal collagen network architecture, manifested by a decreased average collagen fibril diameter, and increased collagen turnover. The glycosaminoglycan content was unchanged. Furthermore, the apparent effects on the stromal cellular composition were limited to a reduction in an NG2-positive stromal cell population. The current data support the hypothesis that the collagen network architecture influences the dynamic exchanges of solutes between blood and carcinoma tissue. It is conceivable that STI571 reprograms distinct nonvascular stromal cells to produce a looser extracellular matrix, ultimately improving transport characteristics for traditional chemotherapeutic agents. Mol Cancer Ther; 15(10); 2455-64. ©2016 AACR.