CRISPR/Cas9 system in breast cancer therapy: advancement, limitations and future scope.

Cancer is one of the major causes of mortality worldwide, therefore it is considered a major health concern. Breast cancer is the most frequent type of cancer which affects women on a global scale. Various current treatment strategies have been implicated for breast cancer therapy that includes surgical removal, radiation therapy, hormonal therapy, chemotherapy, and targeted biological therapy. However, constant effort is being made to introduce novel therapies with minimal toxicity. Gene therapy is one of the promising tools, to rectify defective genes and cure various cancers. In recent years, a novel genome engineering technology, namely the clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein-9 (Cas9) has emerged as a gene-editing tool and transformed genome-editing techniques in a wide range of biological domains including human cancer research and gene therapy. This could be attributed to its versatile characteristics such as high specificity, precision, time-saving and cost-effective methodologies with minimal risk. In the present review, we highlight the role of CRISPR/Cas9 as a targeted therapy to tackle drug resistance, improve immunotherapy for breast cancer.

Patient-derived organoids, creating a new window of opportunities for pancreatic cancer patients.

Standard-of-care regimens for pancreatic ductal adenocarcinoma (PDAC) include a combination of chemotherapies, which are associated with toxicity and eventually tumor resistance. The lack of relevant tool to identify and evaluate new therapies in PDAC necessitates the search for a model, especially for cases with treatment resistance to standard of care. In the study from Peschke et al (2022), they describe a longitudinal platform to identify drug-induced vulnerabilities following standard-of-care chemotherapy treatment using patient-derived organoids (PDOs) providing an opportunity to predict therapeutic response and define new treatment vulnerability induced by standard of care. Previously, tumor resistance to chemotherapy has typically been described as selection for resistant tumor cell populations. However, Peschke et al (2022) demonstrated that PDAC cells seemed to acquire resistance not only through genetic changes, but also through modifications in cellular plasticity leading to gene expression and metabolism changes. Thus, the study supports this type of platform for the identification of new therapeutic targets following standard-of-care treatments in PDAC.

Leishmania donovani inhibits ferroportin translation by modulating FBXL5-IRP2 axis for its growth within host macrophages.

Hepcidin mediated ferroportin (Fpn) degradation in macrophages is a well adopted strategy to limit iron availability towards invading pathogens. Leishmania donovani (LD), a protozoan parasite, resides within macrophage and competes with host for availing iron. Using in vitro and in vivo model of infection, we reveal that LD decreases Fpn abundance in host macrophages by hepcidin independent mechanism. Unaffected level of Fpn-FLAG in LD infected J774 macrophage confirms that Fpn down-regulation is not due its degradation. While increased Fpn mRNA but decreased protein expression in macrophages suggests blocking of Fpn translation by LD infection that is confirmed by 35 S-methionine labelling assay. We further reveal that LD blocks Fpn translation by induced binding of iron regulatory proteins (IRPs) to the iron responsive element present in its 5'UTR. Supershift analysis provides evidence of involvement of IRP2 particularly during in vivo infection. Accordingly, a significant increase in IRP2 protein expression with simultaneous decrease in its stability regulator F-box and leucine-rich repeat Protein 5 (FBXL5) is detected in splenocytes of LD-infected mice. Increased intracellular growth due to compromised expressions of Fpn and FBXL5 by specific siRNAs reveals that LD uses a novel strategy of manipulating IRP2-FBXL5 axis to inhibit host Fpn expression.