Non-invasive molecular imaging of prostate cancer lymph node metastasis

An Extracellular Matrix Overlay Model for Bioluminescence Microscopy to Measure Single-Cell Heterogeneous Responses to Antiandrogens in Prostate Cancer Cells

Prostate cancer (PCa) displays diverse intra-tumoral traits, impacting its progression and treatment outcomes. This study aimed to refine PCa cell culture conditions for dynamic monitoring of androgen receptor (AR) activity at the single-cell level. We introduced an extracellular matrix-Matrigel (ECM-M) culture model, enhancing cellular tracking during bioluminescence single-cell imaging while improving cell viability. ECM-M notably tripled the traceability of poorly adherent PCa cells, facilitating robust single-cell tracking, without impeding substrate permeability or AR response. This model effectively monitored AR modulation by antiandrogens across various PCa cell lines. Single-cell imaging unveiled heterogeneous antiandrogen responses within populations, correlating non-responsive cell proportions with drug IC50 values. Integrating ECM-M culture with the PSEBC-TSTA biosensor enabled precise characterization of ARi responsiveness within diverse cell populations. Our ECM-M model stands as a promising tool to assess heterogeneous single-cell treatment responses in cancer, offering insights to link drug responses to intracellular signaling dynamics. This approach enhances our comprehension of the nuanced and dynamic nature of PCa treatment responses.

Developing a nomogram for preoperative prediction of cervical cancer lymph node metastasis by multiplex immunofluorescence

BACKGROUND

Most traditional procedures can destroy tissue natural structure, and the information on spatial distribution and temporal distribution of immune milieu in situ would be lost. We aimed to explore the potential mechanism of pelvic lymph node (pLN) metastasis of cervical cancer (CC) by multiplex immunofluorescence (mIF) and construct a nomogram for preoperative prediction of pLN metastasis in patients with CC.

METHODS

Patients (180 IB1-IIA2 CC patients of 2009 FIGO (International Federation of Gynecology and Obstetrics)) were divided into two groups based on pLN status. Tissue microarray (TMA) was prepared and tumor-infiltrating immune markers were assessed by mIF. Multivariable logistic regression analysis and nomogram were used to develop the predicting model.

RESULTS

Multivariable logistic regression analysis constructs a predictive model and the area under the curve (AUC) can reach 0.843. By internal validation with the remaining 40% of cases, a new ROC curve has emerged and the AUC reached 0.888.

CONCLUSIONS

This study presents an immune nomogram, which can be conveniently used to facilitate the preoperative individualized prediction of LN metastasis in patients with CC.

Dual-Tracer PET-Computed Tomography Imaging for Precision Radio-Molecular Theranostics of Prostate Cancer: A Futuristic Perspective

Dual/multi-tracer PET-computed tomography (CT) scan has been an interesting and intriguing concept and is promising in noninvasive and overall characterization of tumor biology and heterogeneity and has scientifically augmented the practice of precision oncology. In prostate carcinoma, particularly in metastatic castration-resistant prostate carcinoma setting, dual-tracer PET-CT can be potentially useful in selecting patients for chemotherapy, androgen deprivation therapy or prostate-specific membrane antigen (PSMA)-based peptide receptor radioligand therapy either as mono-therapy or as combination therapy, ascertaining differentiation status, staging/restaging, prognostication, and predicting progression/response. PSMA PET/CT has great potential as a "rule out" test in baseline staging, while being very useful in restaging and metastatic workup.

SPOP promotes cervical cancer progression by inducing the movement of PD-1 away from PD-L1 in spatial localization

Background

Metastasis is a major obstacle in the treatment of cervical cancer (CC), and SPOP-mediated regulatory effects are involved in metastasis. However, the mechanisms have not been fully elucidated.

Methods

Proteomic sequencing and SPOP immunohistochemistry (IHC) were performed for the pelvic lymph node (pLN)-positive and non-pLN groups of CC patients. The corresponding patients were stratified by SPOP expression level for overall survival (OS) and relapse-free survival (RFS) analysis. In vitro and in vivo tests were conducted to verify the causal relationship between SPOP expression and CC metastasis. Multiplex immunofluorescence (m-IF) and the HALO system were used to analyse the mechanism, which was further verified by in vitro experiments.

Results

SPOP is upregulated in CC with pLN metastasis and negatively associated with patient outcome. In vitro and in vivo, SPOP promotes CC proliferation and metastasis. According to m-IF and HALO analysis, SPOP may promote CC metastasis by promoting the separation of PD-1 from PD-L1. Finally, it was further verified that SPOP can achieve immune tolerance by promoting the movement of PD-1 away from PD-L1 in spatial location and function.

Conclusion

This study shows that SPOP can inhibit the immune microenvironment by promoting the movement of PD-1 away from PD-L1, thereby promoting pLN metastasis of CC and resulting in worse OS and RFS.

The SPOP is associated with pelvic lymph node (pLN) metastasis and prognosis in cervical cancer (CC) patients.

This paper discusses the potential mechanism of pLN metastasis of CC from the perspective of spatial location.

This is a multi-cross study, including clinical data, tissue microarray (TMA), multicolor immunofluorescence (m-IF), spatial immunolocalization, in vitro and in vivo functional and mechanism research fusion, from clinical to basic and clinical research.

Development of a Transcriptional Amplification System Based on the PEG3 Promoter to Target Androgen Receptor-Positive and -Negative Prostate Cancer Cells

Localized prostate cancer (PCa) is often curable, whereas metastatic disease treated by castration inevitably progresses toward castration-resistant PCa (CRPC). Most CRPC treatments target androgen receptor (AR) signaling. However, not all CRPC cells rely on AR activity for survival and proliferation. With advances in immunotherapy and fluid biopsies for cancer management, expression systems specific for both AR-positive and -negative PCa are required for virus-based vaccines and cell imaging. To target both AR-responsive and non-responsive cells, we developed a three-step transcriptional amplification (3STA) system based on the progression elevated gene-3 (PEG3) promoter named PEG3AP1-3STA. Notably, we report on different genetic modifications that significantly improved PEG3 promoter's strength in PCa cells. Adenoviruses incorporating PEG3 promoter with and without transcriptional amplification systems were generated. The potential of PEG3AP1-3STA to target PCa cells was then evaluated in vitro and in vivo in androgen-responsive and non-responsive PCa cell lines. PEG3AP1-3STA was shown to be active in all PCa cell lines and not regulated by androgens, and its activity was amplified 97-fold compared to that of a non-amplified promoter. The PEG3AP1-3STA system can thus be used to target advanced AR+ and AR- cells for imaging or immunovirotherapy in advanced PCa.

A PCA3 gene-based transcriptional amplification system targeting primary prostate cancer

Targeting specifically primary prostate cancer (PCa) cells for immune therapy, gene therapy or molecular imaging is of high importance. The PCA3 long non-coding RNA is a unique PCa biomarker and oncogene that has been widely studied. This gene has been mainly exploited as an accurate diagnostic urine biomarker for PCa detection. In this study, the PCA3 promoter was introduced into a new transcriptional amplification system named the 3-Step Transcriptional Amplification System (PCA3-3STA) and cloned into type 5 adenovirus. PCA3-3STA activity was highly specific for PCa cells, ranging between 98.7- and 108.0-fold higher than that for benign primary prostate epithelial or non-PCa cells, respectively. In human PCa xenografts, PCA3-3STA displayed robust bioluminescent signals at levels that are sufficient to translate to positron emission tomography (PET)-based reporter imaging. Remarkably, when freshly isolated benign or cancerous prostate biopsies were infected with PCA3-3STA, the optical signal produced from primary PCa biopsies was significantly higher than from benign prostate biopsies (4.4-fold, p < 0.0001). PCA3-3STA therefore represents a PCa-specific expression system with the potential to target, with high accuracy, primary or metastatic PCa epithelial cells for imaging, vaccines, or gene therapy.

Bioluminescence Microscopy as a Method to Measure Single Cell Androgen Receptor Activity Heterogeneous Responses to Antiandrogens

Cancer cell heterogeneity is well-documented. Therefore, techniques to monitor single cell heterogeneous responses to treatment are needed. We developed a highly translational and quantitative bioluminescence microscopy method to measure single cell androgen receptor (AR) activity modulation by antiandrogens from fluid biopsies. We showed that this assay can detect heterogeneous cellular response to drug treatment and that the sum of single cell AR activity can mirror the response in the whole cell population. This method may thus be used to monitor heterogeneous dynamic treatment responses in cancer cells.

FDG-PET/CT for pre-operative staging and prognostic stratification of patients with high-grade prostate cancer at biopsy

Background

The role of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in prostate cancer (PCa) has not been well defined yet. Because high-grade PCa tends to exhibit increased glycolytic rate, FDG-PET/CT could be useful in this setting. The aim of this study was to assess the value of FDG-PET/CT for pre-operative staging and prognostic stratification of patients with high-grade PCa at biopsy.

Methods

Fifty-four patients with a Gleason sum ≥8 PCa at biopsy underwent FDG-PET/CT as part of the staging workup. Thirty-nine patients underwent radical prostatectomy (RP) and pelvic lymph node (LN) dissection, 2 underwent LN dissection only, and 13 underwent non-surgical treatments. FDG-PET/CT findings from clinical reports, blinded reading and quantitative analysis were correlated with clinico-pathological characteristics at RP.

Results

Suspicious foci of increased FDG uptake were found in the prostate, LNs and bones in 44, 13 and 6% of patients, respectively. Higher clinical stage, post-RP Gleason sum and pattern, and percentage of cancer involvement within the prostate were significantly associated with the presence of intraprostatic FDG uptake (IPFU) (P < 0.05 in all cases). Patients without IPFU who underwent RP were downgraded to Gleason ≤7 in 84.6% of cases, as compared to 30.8% when IPFU was reported (P = 0.003). Qualitative and quantitative IPFU were significantly positively correlated with post-RP Gleason pattern and sum, and pathological T stage. Absence and presence of IPFU were associated with a median 5-year cancer-free survival probability of 70.2 and 26.9% (P = 0.0097), respectively, using the CAPRA-S prognostic tool.

Conclusion

These results suggest that, among patients with a high-grade PCa at biopsy, FDG-PET/CT could improve pre-treatment prognostic stratification by predicting primary PCa pathological grade and survival probability following RP.

Imaging in prostate carcinoma

Imaging plays a central role in the detection, diagnosis, staging, and follow-up of prostate carcinoma. This article discusses the role of multiple imaging modalities in the diagnosis and staging of prostate cancer, with attention to imaging features of localized and metastatic disease, imaging adjuncts to improve prostate biopsy, and potential imaging biomarkers. In addition, the role of imaging in the management of prostate cancer, with emphasis on surveillance, evaluation of response to new therapies, and detection of recurrent disease is described. Lastly, future directions in prostate cancer imaging are presented.

[Imaging diagnostics of advanced prostate cancer]

The diagnostic approach to prostate cancer is still a big challenge for the treating physician. Regarding an individualized and risk-adapted evaluation of different therapeutic options, precise diagnostic tools are crucial to accurately distinguish between localized and advanced prostate cancer. Imaging of advanced prostate cancer is currently changing due to numerous technical innovations. While choline-based hybrid positron emission tomography-computed tomography (PET/CT) has been established as an important diagnostic tool in clinical imaging of advanced prostate cancer, well-investigated methods, such as magnetic resonance imaging (MRI) and bone scintigraphy are currently expanding the diagnostic potential due to technical improvements. The specific use of imaging for advanced prostate cancer may help to offer the patient a well-tailored oncologic therapy. Further research is needed to evaluate whether this individualized therapy can consistently improve the prognosis of patients suffering from advanced prostate cancer.

A molecular imaging system based on both transcriptional and genomic amplification to detect prostate cancer cells in vivo

An imaging modality that can accurately discern prostate cancer (PCa) foci would be useful to detect PCa early or guide treatment. We have engineered numerous adenoviral vectors (Ads) to carry out reporter gene-based imaging using specific promoters to express a potent transcriptional activator, which in turn activates the reporter gene in PCa. This two-step transcriptional amplification (TSTA) method can boost promoters' activity, while maintaining cell specificity. Here, we examined a dual TSTA (DTSTA) approach, which utilizes TSTA not only to express the imaging reporter, but also to direct viral genome replication of a conditionally replicating Ad (CRAd) to further augment the expression levels of the reporter gene by genomic amplification supported in trans by coadministered CRAd. In vitro studies showed up to 50-fold increase of the reporter genome by DTSTA. Compared with TSTA reporter alone, DTSTA application exhibited a 25-fold increase in imaging signal in PCa xenografts. DTSTA approach is also beneficial for a combination of two TSTA Ads with distinct promoters, although amplification is observed only when TSTA-CRAd can replicate. Consequently, the DTSTA approach is a hybrid method of transcriptional and genomic augmentation that can provide higher level reporter gene expression potentially with a lower dose of viral administration.

Lymph node-positive prostate cancer: current issues, emerging technology and impact on clinical outcome

Lymph node metastasis in patients with prostate cancer indicates a poorer prognosis compared with patients without lymph node metastasis; however, some patients with node-positive disease have long-term survival. Many studies have attempted to discern what characteristics of lymph node metastasis are prognostically significant. These characteristics include nodal tumor volume, number of positive lymph nodes, lymph node density, extranodal extension, lymphovascular invasion and tumor dedifferentiation. Favorable characteristics of regional lymph node involvement included a smaller tumor size and smaller tumor volume. However, the current staging system for prostate cancer does not provide different subclassifications for patients with node-positive prostate cancer. In recent years numerous advanced technologies for the detection of lymph node metastasis have been developed, including molecular imaging techniques and the CellSearch Circulating Tumor Cell System. With the increased detection of patients with prostate cancer, emergence of new technology to identify lymph node metastasis and the number of radical prostatectomies being performed on the rise, subclassifying patients with lymph node-positive disease is imperative. Subclassification would provide a better picture of patient prognosis and allow for a better understanding of targeted therapies to treat patients with lymph node metastasis.

Imaging in prostate cancer staging: present role and future perspectives

Despite recent improvements in detection and treatment, prostate cancer continues to be the most common malignancy and the second leading cause of cancer-related mortality. Thus, although survival rate continues to improve, prostate cancer remains a compelling medical health problem. The major goal of prostate cancer imaging in the next decade will be more accurate disease characterization through the synthesis of anatomic, functional, and molecular imaging information in order to plan the most appropriate therapeutic strategy. No consensus exists regarding the use of imaging for evaluating primary prostate cancer. However, conventional and functional imaging are expanding their role in detection and local staging and, moreover, functional imaging is becoming of great importance in oncologic management and monitoring of therapy response. This review presents a multidisciplinary perspective on the role of conventional and functional imaging methods in prostate cancer staging.

Preclinical lymphatic imaging

Noninvasive in vivo imaging of lymphatic vessels and lymphatic nodes is expected to fulfill the purpose of analyzing lymphatic vessels and their function, understanding molecular mechanisms of lymphangiogenesis and lymphatic spread of tumors, and utilizing lymphatic molecular markers as a prognostic or diagnostic indicator. In this review, we provide a comprehensive summary of in vivo imaging modalities for detecting lymphatic vessels, lymphatic drainage, and lymphatic nodes, which include conventional lymphatic imaging techniques such as dyes and radionuclide scintigraphy as well as novel techniques for lymphatic imaging such as optical imaging, computed tomography, magnetic resonance imaging, ultrasound, positron emission tomography using lymphatic biomarkers, photoacoustic imaging, and combinations of multiple modalities. The field of lymphatic imaging is ever evolving, and technological advances, combined with the development of new contrast agents, continue to improve the research of lymphatic vascular system in health and disease states as well as to improve the accuracy of diagnosis in the relevant diseases.

In vivo imaging of intraprostatic-specific gene transcription by PET

Better intraprostatic cancer imaging techniques are needed to guide clinicians in prostate cancer treatment decisions. Because many genes are specifically overexpressed in cancer cells, one strategy to improve prostate cancer detection is to image intraprostatic cancer-specific transcriptional activity. Because of the obstacles of weak cancer- or tissue-specific promoter activity and bladder clearance of many PET tracers, intraprostatic PET of gene transcriptional activity has not been previously reported.

METHODS

The two-step transcriptional amplification (TSTA) system that amplifies the prostate-specific antigen promoter activity was used for PET imaging of the reporter gene herpes simplex virus type-1 sr39 thymidine kinase (HSV1-sr39tk). The TSTA-sr39tk system was injected directly into prostates or prostatic tumors as a replication-incompetent adenovirus (AdTSTA-sr39tk) and imaged using PET.

RESULTS

AdTSTA-sr39tk was able to image prostate-specific antigen promoter transcriptional activity by 9-(4-(18)F-fluoro-3-[hydroxymethyl]butyl)guanine PET, in both mouse and canine prostates in vivo. Ex vivo small-animal PET images, scintigraphic counts, and sr39tk expression analysis confirmed the specificity of the observed signal.

CONCLUSION

Here, by combining the TSTA-amplified signal with a protocol for tracer administration, we show that in vivo PET detection of transcriptional activity is possible in both mouse and immunocompetent canine prostates. These results suggest that imaging applications using transcription-based tumor-specific promoters should be pursued to better visualize cancer foci that escape detection by conventional biopsies.

Oxidative stress and DNA methylation in prostate cancer

The protective effects of fruits, vegetables, and other foods on prostate cancer may be due to their antioxidant properties. An imbalance in the oxidative stress/antioxidant status is observed in prostate cancer patients. Genome oxidative damage in prostate cancer patients is associated with higher lipid peroxidation and lower antioxidant levels. Oxygen radicals are associated with different steps of carcinogenesis, including structural DNA damage, epigenetic changes, and protein and lipid alterations. Epigenetics affects genetic regulation, cellular differentiation, embryology, aging, cancer, and other diseases. DNA methylation is perhaps the most extensively studied epigenetic modification, which plays an important role in the regulation of gene expression and chromatin architecture, in association with histone modification and other chromatin-associated proteins. This review will provide a broad overview of the interplay of oxidative stress and DNA methylation, DNA methylation changes in regulation of gene expression, lifestyle changes for prostate cancer prevention, DNA methylation as biomarkers for prostate cancer, methods for detection of methylation, and clinical application of DNA methylation inhibitors for epigenetic therapy.