The epidermal growth factor receptor (EGFR) family of receptor tyrosine kinases (RTK) consists of four members: EGFR1/ErbB1/HER1, ErbB2/HER2, ErbB3/HER3, and HER4/ErbB4. Signaling through these receptors regulates many key cellular activities, such as cell division, migration, adhesion, differentiation, and apoptosis. The ErbB family has been shown to be overexpressed in different types of cancers and is a target of several inhibitors already in clinical trials. ErbB3 lacks a functional tyrosine kinase domain and therefore has not been as extensively studied as the other members of this family, but its importance in activating downstream pathways, such as the PI3K/Akt pathway, makes this RTK a worthy investigation target, especially in urothelial carcinoma where the PI3K/Akt pathway is vital for progression. In recent times, ErbB3 overexpression has been linked to drug resistance and progression of various diseases, especially cancer. ErbB3 levels in the serum were shown in many cases to be reflective of its role in disease progression, and therefore detection of serum ErbB3 levels during treatment may be of importance.Here we describe two methods for detecting ErbB3 protein in serum from patients who have undergone a clinical trial, utilizing two well-established methods in molecular biology-western blotting and ELISA, focusing on sample preparation and troubleshooting.

The epidermal growth factor receptor (EGFR) family of receptor tyrosine kinases (RTK) consists of four members: EGFR1/ErbB1/HER1, ErbB2/HER2, ErbB3/HER3, and HER4/ErbB4. Signaling through these receptors regulates many key cellular activities, such as cell division, migration, adhesion, differentiation, and apoptosis. The ErbB family has been shown to be overexpressed in different types of cancers and is a target of several inhibitors already in clinical trials. ErbB3 lacks a functional tyrosine kinase domain and therefore has not been as extensively studied as the other members of this family, but its importance in activating downstream pathways, such as the PI3K/Akt pathway, makes this RTK a worthy investigation target, especially in urothelial carcinoma where the PI3K/Akt pathway is vital for progression. In recent times, ErbB3 overexpression has been linked to drug resistance and progression of various diseases, especially cancer. ErbB3 levels in the serum were shown in many cases to be reflective of its role in disease progression, and therefore detection of serum ErbB3 levels during treatment may be of importance.Here we describe two methods for detecting ErbB3 protein in serum from patients who have undergone a clinical trial, utilizing two well-established methods in molecular biology-western blotting and ELISA, focusing on sample preparation and troubleshooting.

Platinum-based chemotherapy is commonly used for the treatment of locally advanced and metastatic bladder cancer. However, there are currently no methods to predict chemotherapy response in this disease setting. A better understanding of the biology of bladder cancer has led to developments of molecular biomarkers that may help guide clinical decision making. These biomarkers, while promising, have not yet been validated in prospective trials and are not ready for clinical applications. As alkylating agents, platinum drugs kill cancer cells mainly through induction of DNA damage. A microdosing approach is currently being tested to determine if chemoresistance can be identified by measuring platinum-induced DNA damage using highly sensitive accelerator mass spectrometry technology. The hope is that these emerging strategies will help pave the road towards personalized therapy in advanced bladder cancer.

Nanotechnology is being developed for the diagnosis and treatment of both nonmyoinvasive bladder cancer (NMIBC) and invasive bladder cancer. The diagnostic applications of nanotechnology in NMIBC mainly focus on tumor identification during endoscopy to increase complete resection of bladder cancer while nanotechnology to capture malignant cells or their components continues to be developed. The therapeutic applications of nanotechnology in NMIBC are to reformulate biological and cytotoxic agents for intravesical instillation, combine both diagnostic and therapeutic application in one nanoformulation. In invasive and advanced bladder cancer, magnetic resonance imaging with supraparamagnetic iron oxide nanoparticles can improve the sensitivity and specificity in detecting small metastasis to lymph nodes. Nanoformulation of cytotoxic agents can potentially decrease the toxicity while increasing efficacy.

Patient-derived xenograft (PDX) models allow for personalized drug selection and the identification of drug resistance mechanisms in cancer cells. However, PDX models present technical disadvantages, such as long engraftment time, low success rate, and high maintenance cost. On the other hand, tumor spheroids are emerging as an in vitro alternative model that can maintain the phenotype of cancer cells long enough to perform all assays and predict a patient's outcome. The present work aimed to describe a simple, reproducible, and low-cost 3D in vitro culture method to generate bladder tumor spheroids using human cells from PDX mice. Cancer cells from PDX BL0293 and BL0808 models, previously established from advanced bladder cancer, were cultured in 96-well round-bottom ultra-low attachment (ULA) plates with 5% Matrigel and generated regular and round-shaped spheroids (roundness > 0.8) with a diameter larger than 400 μm and a hypoxic core (a feature related to drug resistance in solid tumors). The responses of the tumor spheroids to the antineoplastic drugs cisplatin, gemcitabine, and their combination were similar to tumor responses in in vivo studies with PDX BL0293 and BL0808 mice. Therefore, the in vitro 3D model using PDX tumor spheroids appears as a valuable tool that may predict the outcome of in vivo drug-screening assays and represents a low-cost strategy for such purpose.

Prognosis of castration-resistant prostate cancer (CRPC) carries is poor, and no effective therapeutic regimen is yet known. The phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway played a predominant role and may be a promising molecular target for CRPC. However, the toxicity of the dual PI3K inhibitors in clinical trials limits their clinical efficacy for CRPC. To solve this problem, we employed a highly integrated precision nanomedicine strategy to molecularly and physically target CRPC through synergistic effects, enhanced targeted drug delivery efficiency, and reduced unwanted side-effects. Gedatolisib (Ge), a potent inhibitor of PI3K/mTOR, was formulated into our disulfied-crosslinked micelle plateform (NanoGe), which exhibits excellent water solubility, small size (23.25±2 nm), excellent stability with redox stimulus-responsive disintegration, and preferential uptake at tumor sites. NanoGe improved the anti-neoplastic effect of free Ge by 53 times in PC-3M cells and 13 times in C4-2B cells though its enhanced uptake via caveolae- and clathrin-mediated endocytic pathways and the subsequent inhibition of the PI3K/mTOR pathway, resulting in Bax/Bcl-2 dependent apoptosis. In an animal xenograft model, NanoGe showed superior efficacy than free Ge, and synergized with nanoformulated cabazitaxel (NanoCa) as a nanococktail format to achieve a cure rate of 83%. Taken together, our results demonstrate the potency of NanoGe in combination with NanoCa is potent against prostate cancer.

Acute myeloid leukemia (AML) is a rare yet deadly cancer of the blood and bone marrow. Presently, induction chemotherapy with the DNA damaging drugs cytarabine (ARA-C) and idarubicin (IDA), known as 7 + 3, is the standard of care for most AML patients. However, 7 + 3 is a relatively ineffective therapy, particularly in older patients, and has serious therapy-related toxicities. Therefore, a diagnostic test to predict which patients will respond to 7 + 3 is a critical unmet medical need. We hypothesize that a threshold level of therapy-induced 7 + 3 drug-DNA adducts determines cytotoxicity and clinical response. We further hypothesize that in vitro exposure of AML cells to nontoxic diagnostic microdoses enables prediction of the ability of AML cells to achieve that threshold during treatment. Our test involves dosing cells with very low levels of ¹⁴C-labeled drug followed by DNA isolation and quantification of drug-DNA adducts via accelerator mass spectrometry. Here, we have shown proof of principle by correlating ARA-C- and DOX-DNA adduct levels with cellular IC₅₀ values of paired sensitive and resistant cancer cell lines and AML cell lines. Moreover, we have completed a pilot retrospective trial of diagnostic microdosing for 10 viably cryopreserved primary AML samples and observed higher ARA-C- and DOX-DNA adducts in the 7 + 3 responders than nonresponders. These initial results suggest that diagnostic microdosing may be a feasible and useful test for predicting patient response to 7 + 3 induction chemotherapy, leading to improved outcomes for AML patients and reduced treatment-related morbidity and mortality.

Immunotherapy has become the central pillar of cancer therapy. Immune checkpoint inhibitors (ICIs), a major category of tumor immunotherapy, reactivate preexisting anticancer immunity. Initially, ICIs were approved only for advanced and metastatic cancers in the salvage setting after or concurrent with chemotherapy at a response rate of around 20-30% with a few exceptions. With significant progress over the decade, advances in immunotherapy have led to numerous clinical trials investigating ICIs as neoadjuvant and/or adjuvant therapies for resectable solid tumors. The promising results of these trials have led to the United States Food and Drug Administration (FDA) approvals of ICIs as neoadjuvant or adjuvant therapies for non-small cell lung cancer, melanoma, triple-negative breast cancer, and bladder cancer, and the list continues to grow. This therapy represents a paradigm shift in cancer treatment, as many early-stage cancer patients could be cured with the introduction of immunotherapy in the early stages of cancer. Therefore, this topic became one of the main themes at the 2021 China Cancer Immunotherapy Workshop co-organized by the Chinese American Hematologist and Oncologist Network, the China National Medical Products Administration and the Tsinghua University School of Medicine. This review article summarizes the current landscape of ICI-based immunotherapy, emphasizing the new clinical developments of ICIs as curative neoadjuvant and adjuvant therapies for early-stage disease.

This rapid report focuses on the pharmacodynamic mechanism of the carboplatin/paclitaxel combination and correlates it with its cytotoxicity. Consistent with the synergistic to additive antitumor activity (the combination index ranging from 0.53 to 0.94), cells exposed to this combination had significantly increased carboplatin-DNA adduct formation when compared to that of carboplatin alone (450 ± 30 versus 320 ± 120 adducts per 10(8) nucleotides at 2 h, p = 0.004). Removal of paclitaxel increased the repair of carboplatin-DNA adducts: 39.4 versus 33.1 adducts per 10(8) nucleotides per hour in carboplatin alone (p = 0.021). This rapid report provides the first pharmacodynamics data to support the use of carboplatin/paclitaxel combination in the clinic.

Purpose

Bladder cancer is a common malignancy often diagnosed in older adults. Previous studies have reported racial/ethnic disparities in bladder cancer survival outcomes but have not focused on younger patients. We identified whether factors influencing cause specific survival in adolescents and young adults (ages 15 to 39) differed from older adults, and defined prognostic factors specifically in adolescents and young adults using the California Cancer Registry.

Materials and methods

Patients diagnosed with bladder cancer between 1988 through 2012 were included in the study. The primary outcome measure was cause specific survival. A multivariable Cox proportional hazards regression model was used to evaluate predictors of cause specific survival in patients of all ages and in adolescents/young adults. Interactions of age and other variables between younger and older adult patients were assessed.

Results

Of 104,974 patients with bladder cancer we identified 1,688 adolescent and young adult patients (1.6%). Compared to older patients these patients had a 58% reduced risk of bladder cancer death (HR 0.42, p <0.001). Significant age interactions were identified involving race/ethnicity and histology. Among adolescents and young adults, nonHispanic African-American patients with low socioeconomic status had poor cause specific (HR 7.1, p <0.001) and overall (HR 5.02, p <0.001) survival.

Conclusions

Racial/ethnic and socioeconomic disparities exist in adolescent and young adult patients with bladder cancer in California. Further studies are warranted to identify the underlying causes in order to overcome these disparities.