New Way to Diagnose Tumor at an Early Stage

A new study finding shows the possibility of designing smarter photoacoustic (PA) probes for the precise diagnosis of tumors.

The specific imaging of a potential tumor biomarker through a probe can detect many cancer types at an early stage, according to a study published in Angewandte Chemie International Edition.

As survival rates differ greatly between cancer patients treated at early or late stages, early detection of tumors is of great importance to cancer therapy.

Tumor Lysis Syndrome - Risk Factors, Symptoms, Diagnosis & Treatment
Tumor lysis syndrome is a collection of metabolic abnormalities due to the tumor cell lysis in patients with treatment for malignancies.

‘Early detection of tumor is possible through Cathepsin B (CTSB)-initiated intracellular self-assembly of small-molecule PA imaging probes into nanoparticles.’

Cathepsin B (CTSB) is considered as a potential biomarker for the early diagnosis of cancers due to its increased expression in the early stage of many cancer types. As a result, the effective and precise monitoring of CTSB activity offers a way out.

Taking this into account, a research team from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences used photoacoustic (PA) imaging for CTSB in tumor detection in a new study.

PA imaging is a new type of non-invasive and non-ionizing biomedical imaging method, which has a huge potential in biomedical research and disease diagnosis due to its excellent tissue-penetrating depth and high spatial resolution.

Tumor Metastasis Can Now be Prevented: Here�s How
Prevention of tumor metastasis is now possible. The molecular mechanism of cancer metastasis involves a cell surface receptor called CCR7. Certain potential drug molecules have been identified that block CCR7, which could prevent metastasis.

Using the self-assembly signal enhancement of PA imaging probe, they designed a CTSB-activatable near-infrared PA probe Val-Cit-Cys(SEt)-Lys(Cypate)-CBT (Cypate-CBT).

When Cypate-CBT enters CTSB-overexpressing tumor cells, its disulfide bond is reduced by intracellular glutathione, and its specific cleavage substrate Val-Cit is cleaved by CTSB to produce Cypate-CBT-Cleaved, which undergoes an intermolecular CBT-Cys click reaction to yield Cypate-CBT-Dimer.

Cancer Can be Detected Using Tattoo Ink and Food Dyes
Detection of cancer is possible by using an imaging technique coupled with nanoparticles loaded with coloring agents such as tattoo inks and food dyes.

The Cypate-CBT-Dimer then self-assembles into near-infrared nanoparticles Cypate-CBT-NPs.

This approach effectively increases local probe concentration, prolongs the retention time, and enhances the PA signal of the probe for CTSB activity imaging.

About Brain Tumor
Brain tumors are the abnormal growth of brain cells that may be benign or metastatic. Brain tumors account for about 2.4% of all the tumor diagnosesandare most challenging due to their critically delicate location.

They also found that compared with unmodified Cypate, the newly designed probe showed a 4.9-fold and 4.7-fold PA signal enhancement in CTSB-overexpressing MDA-MB-231 cancer cells or tumors, respectively.

Source-Medindia