Targeted Delivery of Therapeutics to Urological Cancer Stem Cells

Progressing nanotechnology to improve targeted cancer treatment: overcoming hurdles in its clinical implementation

The use of nanotechnology has the potential to revolutionize the detection and treatment of cancer. Developments in protein engineering and materials science have led to the emergence of new nanoscale targeting techniques, which offer renewed hope for cancer patients. While several nanocarriers for medicinal purposes have been approved for human trials, only a few have been authorized for clinical use in targeting cancer cells. In this review, we analyze some of the authorized formulations and discuss the challenges of translating findings from the lab to the clinic. This study highlights the various nanocarriers and compounds that can be used for selective tumor targeting and the inherent difficulties in cancer therapy. Nanotechnology provides a promising platform for improving cancer detection and treatment in the future, but further research is needed to overcome the current limitations in clinical translation.

Cancer Stem Cell Markers for Urinary Carcinoma

Cancer stem cell (CSC) refers to cancer cells with stem cell properties, that is, they have the ability of “self-renewal” and “differentiation.” Cancer stem cells exist in cancer cells and are the “culprit” of cancer recurrence and metastasis. It is difficult to be found because of its small amount, and it is difficult for anticancer drugs to produce effects on it. At present, the isolation and identification of cancer stem cells from many solid tumors are still quite difficult, mainly due to the lack of specific molecular markers of cancer stem cells. In this review, cancer stem cell surface markers and functional markers in urinary system were summarized. These markers can provide molecular targets for cancer therapy.

Alternative models of cancer stem cells: The stemness phenotype model, 10 years later

The classical cancer stem cell (CSCs) theory proposed the existence of a rare but constant subpopulation of CSCs. In this model cancer cells are organized hierarchically and are responsible for tumor resistance and tumor relapse. Thus, eliminating CSCs will eventually lead to cure of cancer. This simplistic model has been challenged by experimental data. In 2010 we proposed a novel and controversial alternative model of CSC biology (the Stemness Phenotype Model, SPM). The SPM proposed a non-hierarchical model of cancer biology in which there is no specific subpopulation of CSCs in tumors. Instead, cancer cells are highly plastic in term of stemness and CSCs and non-CSCs can interconvert into each other depending on the microenvironment. This model predicts the existence of cancer cells ranging from a pure CSC phenotype to pure non-CSC phenotype and that survival of a single cell can originate a new tumor. During the past 10 years, a plethora of experimental evidence in a variety of cancer types has shown that cancer cells are indeed extremely plastic and able to interconvert into cells with different stemness phenotype. In this review we will (1) briefly describe the cumulative evidence from our laboratory and others supporting the SPM; (2) the implications of the SPM in translational oncology; and (3) discuss potential strategies to develop more effective therapeutic regimens for cancer treatment.

Clinical therapies and nano drug delivery systems for urinary bladder cancer

Bladder cancer is the 10^th most commonly occurring malignancy worldwide with a 75% of 5-year survival rate, while it ranks 13^th among the deaths occurring due to cancer. The majority of bladder cancer cases are diagnosed at an early stage and 70% are of non-invasive grade. However, 70% of these cases develop chemoresistance and progress to the muscle invasive stage. Conventional chemotherapy treatments are unsuccessful in curbing chemoresistance, bladder cancer progression while having an adverse side effect, which is mainly due to off-target drug distribution. Therefore, new drug delivery strategies, new therapeutics and therapies or their combination are being explored to develop better treatments. In this regard, nanotechnology has shown promise in the targeted delivery of therapeutics to bladder cancer cells. This review discusses the recent discovery of new therapeutics (chemotherapeutics, immunotherapeutic, and gene therapies), recent developments in the delivery of therapeutics using nano drug delivery systems, and the combination treatments with FDA-approved therapies, i.e., hyperthermia and photodynamic therapy. We also discussed the potential of other novel drug delivery systems that are minimally explored in bladder cancer. Lastly, we discussed the clinical status of therapeutics and therapies for bladder cancer. Overall, this review can provide a summary of available treatments for bladder cancer, and also provide opportunities for further development of drug delivery systems for better management of bladder cancer.