Molecular and functional imaging in cancer-targeted therapy: current applications and future directions

Abstract

Targeted anticancer drugs block cancer cell growth by interfering with specific signaling pathways vital to carcinogenesis and tumor growth rather than harming all rapidly dividing cells as in cytotoxic chemotherapy. The Response Evaluation Criteria in Solid Tumor (RECIST) system has been used to assess tumor response to therapy via changes in the size of target lesions as measured by calipers, conventional anatomically based imaging modalities such as computed tomography (CT), and magnetic resonance imaging (MRI), and other imaging methods. However, RECIST is sometimes inaccurate in assessing the efficacy of targeted therapy drugs because of the poor correlation between tumor size and treatment-induced tumor necrosis or shrinkage. This approach might also result in delayed identification of response when the therapy does confer a reduction in tumor size. Innovative molecular imaging techniques have rapidly gained importance in the dawning era of targeted therapy as they can visualize, characterize, and quantify biological processes at the cellular, subcellular, or even molecular level rather than at the anatomical level. This review summarizes different targeted cell signaling pathways, various molecular imaging techniques, and developed probes. Moreover, the application of molecular imaging for evaluating treatment response and related clinical outcome is also systematically outlined. In the future, more attention should be paid to promoting the clinical translation of molecular imaging in evaluating the sensitivity to targeted therapy with biocompatible probes. In particular, multimodal imaging technologies incorporating advanced artificial intelligence should be developed to comprehensively and accurately assess cancer-targeted therapy, in addition to RECIST-based methods.

A Mathematical Model for Simulating Photoacoustic Signal Generation Process in Biological Tissues

“…For instance: photoacoustic tomography (PAT) [1, 2, 4, 31 -33], multispectral optoacoustic tomography (MSOT) [5] or multispectral PAT, light emitting diode (LED) based PAI [34], optical detection PAT (OD-PAT) or also named non-contact laser ultrasound (NC-LUS) [35 -37], photoacoustic microscopy (PAM) [30,38], optical resolution photoacoustic microscopy (OR-PAM) [39], acoustic resolution photoacoustic microscopy (AR-PAM) [30], raster-scan optoacoustic mesoscopy (RSOM) [5], LED based PA microscopy (LD-PAM) [40], Second generation PA remote sensing based microscopy [41], PA endoscopy which is providing molecular contrast at considerable depths allowing for simultaneous imaging of structural and functional information [5,42,43], PA topography through an ergodic relay (PATER) [44], and photoacoustic elastography (PAE) [45 -47]. PAI has a big contribution in cancer diagnosis [5,48,49] as instance in breast cancer [4,5,9,50], which has a high record in threatening human's health, mostly females [51,52], the second most frequent cancer worldwide following lung cancer and the fifth leading cause of cancer death and a major cause of cancer death among women [53 -55]. Imaging Alzheimer's disease would be sensible by PAI of brain.…”

High-Affinity NIR-Fluorescent Inhibitors for Tumor Imaging via Carbonic Anhydrase IX

“…Yield: 116.0 mg, 62%, yellow oily residue. 1 -6). AZ21-4 (32 mg, 0.038 mmol) was dissolved in dichloromethane (7 mL) and TFA (0.3 mL), and the reaction mixture was stirred for 2 h at room temperature.…”

RNA-cleaving DNAzymes for accurate biosensing and gene therapy

“…82 In this process, some signaling pathways that determine cell growth, division, and proliferation are improperly activated, while some apoptosis related signaling pathways are blocked, ultimately leading to the occurrence of cancers. 83 Although a series of gene therapy strategies targeting these abnormal genes have acquired significant breakthrough in cancer treatment, metastasis, immunosuppression, and treatment resistance is still the main restriction to cure cancers. Given the significant advantages of DNAzymes, the gene intervention strategy using RNA-cleaving DNAzymes is expected to be a promising alternative for solving the above problems in cancer gene therapy.…”