Decreased DAB2IP gene expression, which could be induced by fractionated irradiation, is associated with resistance to γ‑rays and α‑particles in prostate cancer cells

Genetic profiling in radiotherapy: a comprehensive review

This comprehensive review explores the pivotal role of radiotherapy in cancer treatment, emphasizing the diverse applications of genetic profiling. The review highlights genetic markers for predicting radiation toxicity, enabling personalized treatment planning. It delves into the impact of genetic profiling on radiotherapy strategies across various cancer types, discussing research findings related to treatment response, prognosis, and therapeutic resistance. The integration of genetic profiling is shown to transform cancer treatment paradigms, offering insights into personalized radiotherapy regimens and guiding decisions in cases where standard protocols may fall short. Ultimately, the review underscores the potential of genetic profiling to enhance patient outcomes and advance precision medicine in oncology.

Down-regulation of autophagy-associated protein increased acquired radio-resistance bladder cancer cells sensitivity to taxol

BACKGROUND

As a bladder-preserving therapy, radiation therapy (RT) has been widely used in the treatment of bladder cancer (BCa) and made great progress in the past few decades. However, some BCa patients have low RT responsiveness and local recurrence rate after RT could reach 50%. Acquired radio-resistance (ARR) is one of the important reasons for the failure of RT. Unfortunately, these ARR cells also lack sensitivity to chemotherapy and cause tumor recurrence and metastasis.

PURPOSE

To build ARR-phenotype BCa cell model, discuss the possible molecular mechanism of ARR and find effective target molecules to overcome ARR.

MATERIALS AND METHODS

Five thousand six hundred and thirty-seven cells were subjected 30 times to 2 Gy of γ-rays and the surviving cells were called 5637R. Colony formation and MTT assay were applied to evaluate cells sensitivity to ionizing radiation (IR) and anti-neoplastic agents, respectively. Cells abilities of migration and invasion were determined using transwell method. Quantitative real-time polymerase chain reaction (RT-qPCR) and western blot (WB) were respectively utilized to compare the difference of gene and protein expression between 5637 and 5637R cells. Molecule inhibitors and small interfering RNA (siRNA) systems were employed to decrease the expression of target proteins, respectively.

RESULTS

BCa cells survived from fractionated irradiation (FI) exhibited tolerance to both IR and chemotherapy drugs. These ARR cells (5637R) had elevated migration and invasion abilities, accompanied by increased expression of epithelial mesenchymal transition (EMT)-related transcription factors (ZEB1/Snail/Twist). Moreover, 5637R cells showed enhanced cancer stem cell (CSC)-like characteristics with activated KMT1A-GATA3-STAT3 circuit, a newly reported self-renewal pathway of human bladder cancer stem cell (BCSC). Combined with Kaplan-Meier's analysis, we speculated that GATA3/MMP9/STAT3 could be an effective molecular panel predicting poor prognosis of BCa. In order to enhance the sensitivity of resistant cells to radiation, we introduced ERK inhibitor (FR 180204) and STAT3 inhibitor (S3I-201). However, both of them could not enhance ARR cells response to IR. On the other hand, siRNAs were respectively implemented to inhibit the expression of endogenous Beclin1 and Atg5, two important autophagy-related genes, in BCa cells, which significantly increased 5637R cells death upon taxol exposing. Similarly, chloroquine (CQ), a classic autophagy inhibitor, enhanced the cytotoxicity of taxol only on 5637R cells.

CONCLUSIONS

Long-term FI treatment is an effective method to establish the ARR-phenotype BCa cell model, by enriching BCSCs and enhancing cells migration and invasion. Both inhibiting the expression of autophagy-related proteins and using autophagy inhibitor can increase the sensitivity of ARR cells to taxol, suggesting that autophagy may play an important role in ARR cells chemical tolerance.

Upregulation of DAB2IP Inhibits Ras Activity and Tumorigenesis in Human Pancreatic Cancer Cells

KRAS mutation-induced Ras activation plays an important role in the pathogenesis of pancreatic cancer, but the role of wild-type Ras and Ras GTPase-activating proteins remains unclear. The present study was designed to determine the expression spectra of Ras GTPase-activating proteins genes in pancreatic cancer cells, and the role of DAB2IP, a Ras GTPase-activating proteins gene, in the development and progression of pancreatic cancer. Following the analyses of the expression profiles of 16 Ras GTPase-activating proteins in 6 pancreatic cancer cell lines including Bxpc-3 (with wild-type KRAS), Capan-2, Sw1990, Aspc-1, CFPAC-1, and Panc-1 (with mutant KRAS) and 1 normal human pancreatic ductal epithelial cell line, H6C7, the expression of DAB2IP messenger RNA was further analyzed by quantitative real-time polymerase chain reaction. The role of DAB2IP in pancreatic cancer was further investigated in vitro and in vivo by upregulating DAB2IP in Bxpc-3 cells through transfection of DAB2IP into Bxpc-3 cells with recombinant lentivirus. The DAB2IP expression in pancreatic cancer cells and tissues with wild-type KRAS was significantly lower than that in cells and tissues with mutant KRAS (P < .05). In Bxpc-3 cells with wild-type KRAS, overexpression of DAB2IP decreased the expression of P-AKT and P-ERK and the Ras activity; increased the expression of P-JNK and caspase 3; inhibited cell proliferation, invasiveness, and migration; and increased the cell sensitivity to cetuximab. Overexpression of DAB2IP inhibited tumor progression in a mouse model. In conclusion, DAB2IP downregulates Ras activity in wild-type pancreatic cancer cells. Overexpression of DAB2IP decreases the Ras activity, inhibits cell proliferation, and increases sensitivity to cetuximab in wild-type pancreatic cancer cells. In conclusion, DAB2IP may serve as a potential molecular therapeutic target for the treatment of pancreatic cancer.

Prediction of Radioresistant Prostate Cancer Based on Differentially Expressed Proteins

INTRODUCTION

Although relapses after radiotherapy are common in prostate cancer (PCA) patients, those with a high risk for radioresistance cannot be identified prior to treatment yet. Therefore, this proof-of-concept study was performed to compare protein expression profiles of patients with radio-recurrent PCA to patients treated with primary radical prostatectomy separated by Gleason risk groups. We hypothesized that radio-recurrent PCA have a similar protein expression as high-risk Gleason PCA.

METHODS

Patient cohorts consisted of (i) 31 patients treated with salvage prostatectomy for locally recurrent PCA after primary radiotherapy and (ii) 94 patients treated with primary prostatectomy split into a Gleason high-risk (≥4 + 3; n = 42 [44.7%]) versus a low-risk group (≤3 + 4; n = 52 [55.3%]). Immunohistochemistry was performed using 15 antibodies with known association to radioresistance in PCA in vitro. ELISA was used for validation of selected markers in serum.

RESULTS

Androgen receptor (AR) was overexpressed in most radio-recurrent PCA (89.7%) and in most primary high-risk Gleason PCA (87.8%; p = 0.851), while only 67.3% of the low-risk group showed an expression (p = 0.017). Considering the highest Gleason pattern in primary PCA, aldo-keto reductase family 1 member C3 (AKR1C3) was most similarly expressed by patients with radio-recurrent PCA and patients with Gleason patterns 4 and 5 (p = 0.827 and p = 0.893) compared to Gleason pattern 3 (p = 0.20). These findings were supported by ELISA.

CONCLUSION

This is the first study to evaluate protein markers in order to predict radioresistance in PCA. Our results point to AR and AKR1C3 as the most promising markers that might help stratify patients for radiotherapy.

Low Expression of ASK1-Interacting Protein-1 Is Significantly Correlated with Tumor Angiogenesis and Poor Survival in Patients with Early Stage Non-Small Cell Lung Cancer

Objective

To investigate the expression of tumor suppressor protein ASK1-interacting protein-1 (AIP1) in cancer tissues of patients with early-stage non-small cell lung cancer (NSCLC) and its correlation with tumor progression, tumor angiogenesis and prognosis.

Methods

A total of 136 patients with stage I NSCLC who underwent radical resection of lung cancer in Qianfoshan Hospital of Shandong Province from January 2011 to December 2011 were enrolled. Immunohistochemistry was used to detect AIP1 protein in tumor tissues. Vascular endothelial CD34 immunohistochemical staining was used to count intratumoral microvessel density (MVD). SPSS 19.0 software was used to analyze the relationship between AIP1 protein expression and clinicopathological features, tumor angiogenesis and prognosis.

Results

Low expression of AIP1 was more common in tumor tissues with high MVD, and patients with low expression of AIP1 were more likely to have tumor recurrence. Multivariate analysis showed that low expression of AIP1 had predictive value for overall survival, disease-free survival, and disease-specific survival.

Conclusion

Downregulation of AIP1 protein expression is associated with lung cancer progression, tumor angiogenesis and poor prognosis. Consequently, AIP1 may prove to be an important predictor of recovery from lung cancer and could become a new therapeutic target for lung cancer treatment.

Exosomes impact survival to radiation exposure in cell line models of nervous system cancer

Radiation is utilized in the therapy of more than 50% of cancer patients. Unfortunately, many malignancies become resistant to radiation over time. We investigated the hypothesis that one method of a cancer cell's ability to survive radiation occurs through cellular communication via exosomes. Exosomes are cell-derived vesicles containing DNA, RNA, and protein. Three properties were analyzed: 1) exosome function, 2) exosome profile and 3) exosome uptake/blockade. To analyze exosome function, we show radiation-derived exosomes increased proliferation and enabled recipient cancer cells to survive radiation in vitro. Furthermore, radiation-derived exosomes increased tumor burden and decreased survival in an in vivo model. To address the mechanism underlying the alterations by exosomes in recipient cells, we obtained a profile of radiation-derived exosomes that showed expression changes favoring a resistant/proliferative profile. Radiation-derived exosomes contain elevated oncogenic miR-889, oncogenic mRNAs, and proteins of the proteasome pathway, Notch, Jak-STAT, and cell cycle pathways. Radiation-derived exosomes contain decreased levels of tumor-suppressive miR-516, miR-365, and multiple tumor-suppressive mRNAs. Ingenuity pathway analysis revealed the most represented networks included cell cycle, growth/survival. Upregulation of DNM2 correlated with increased exosome uptake. To analyze the property of exosome blockade, heparin and simvastatin were used to inhibit uptake of exosomes in recipient cells resulting in inhibited induction of proliferation and cellular survival. Because these agents have shown some success as cancer therapies, our data suggest their mechanism of action could be limiting exosome communication between cells. The results of our study identify a novel exosome-based mechanism that may underlie a cancer cell's ability to survive radiation.

Activation of tumor cell integrin αvβ3 by radiation and reversal of activation by chemically modified tetraiodothyroacetic acid (tetrac)

PURPOSE

Integrin αvβ3 is an important structural and signaling protein of the plasma membrane of cancer cells and dividing blood vessel cells. The plastic extracellular domain of the protein binds to extracellular matrix proteins and plasma membrane proteins, changing cell-cell interactions and generating intracellular signals that influence cell behavior. αvβ3 also contains a receptor for thyroid hormone and derivatives, including tetraiodothyroacetic acid (tetrac).

MATERIALS AND METHODS

Human prostate cancer (PC3) cells were engrafted in the chicken chorioallantoic membrane model. The well-vascularized spheroidal xenografts were exposed to X-radiation in varying dosages (1-10 Gy) and in the presence and absence of an antibody that recognizes unliganded human β3 integrin monomer in the extended or open (activated) configuration.

RESULTS

Radiation significantly increased activated β3 within 1 h (P < .001), a radiation response not previously reported. Incubation of cells with unmodified tetrac or tetrac covalently linked to a nanoparticle (Nanotetrac, NDAT) did not change basal activation state of the integrin monomer, but prevented radiation-induced activation of β3.

CONCLUSIONS

Activation of the integrin in response to radiation is interpreted as a defensive response, perhaps leading to increased intercellular affinity and inhibition of cell division, a radioresistant state. Action of NDAT indicates that pharmacologic interventions in the radiation response of integrin β3 monomer and therefore of αvβ3 are feasible.

Promotion of Cell Proliferation through Inhibition of Cell Autophagy Signalling Pathway by Rab3IP is Restrained by MicroRNA-532-3p in Gastric Cancer

Background: RAB3A-interacting protein (Rab3IP) is known to be involved in cancer; however, its function during the proliferation of gastric cancer (GC) cells remains unknown. Therefore, this study aimed to explore the potential function of Rab3IP in GC. Methods: The expression of Rab3IP and its clinical pathology value were determined by quantitative real-time PCR and immunohistochemistry. Rab3IP (knockdown and overexpression) and light chain 3 (LC3) lentiviruses were transfected into GC cells, and cell proliferation was measured using cell counting kit-8, plate clone formation, flow cytometry, and tumorigenesis assays. Cell autophagy was measured using a confocal laser scanning microscope and by western blotting. Luciferase reporter assay was performed to analyse the regulation of Rab3IP by microRNA-532-3p (miR-532-3p). Results: Overexpression of Rab3IP in GC samples enhanced the cell proliferation ability, but decreased the number of autophagosomes and expression of LC3-II and sequestosome-1 (SQSTM1 or p62) markers. Furthermore, we found that miR-532-3p can bind to the 3'UTR region of RAB3IP and inhibit the proliferation ability of GC cells. Further, the expression of miR-532-3p negatively correlated with that of Rab3IP. Conclusions: Our study elucidates the central role of Rab3IP in inducing proliferation of GC cells through its involvement in autophagy. miR-532-3p directly targets Rab3IP and represses its function, thereby demonstrating a novel regulatory link in GC.

A potential clinical significance of DAB2IP and SPRY2 transcript variants in prostate cancer

Deregulation of key signaling pathways is one of the primary phenomena in carcinogenesis. DAB2IP and SPRY2 are regulatory elements, which act as feedback inhibitors of receptor tyrosine kinases signaling in mitogen-activated protein kinase pathway. These elements have also been implicated in the pathophysiology of cancer. Therefore, this study is aimed to investigate the expression of all known splice variants of DAB2IP and SPRY2 in prostate tissue. Fresh Prostate tissue samples (50 prostate cancer/ matched normal tissue and 30 BPH) were collected and total RNA was extracted followed by cDNA synthesis. The expression of DAB2IP and SPRY2 transcript variants were evaluated using RT-PCR and quantitative Real-time PCR. The results indicated significant down-regulation of DAB2IP transcript variant 1 in cancerous tissues compared to paired normal tissues (P = 0.001) as well as SPRY2 transcript variant 2 in cancerous tissues in comparison with the normal counterparts and BPH (P = 0.008 and P = 0.025, respectively). In addition, there was a significant negative correlation between DAB2IP.1 and SPRY2.2 expression with PSA levels in prostate cancer (P = 0.039 ρ =-0.24 and P = 0.045 ρ =-0.3, respectively). Interestingly, the down-regulation of DAB2IP.1 mRNA and SPRY2.2 mRNA was positively correlated in tumor samples (P = 0.002 ρ = 0.434). For the first time, this experiment highlights the deregulation of DAB2IP and SPRY2 transcript variants in human prostate cancer. The present study confirms and extends the previous reports through indicating transcript-specific down-regulation and significant association of DAB2IP and SPRY2 in prostate tumorigenesis.

Clair DK, Kyprianou N. Profiles of Radioresistance Mechanisms in Prostate Cancer

Radiation therapy (RT) is commonly used for the treatment of localized prostate cancer (PCa). However, cancer cells often develop resistance to radiation through unknown mechanisms and pose an intractable challenge. Radiation resistance is highly unpredictable, rendering the treatment less effective in many patients and frequently causing metastasis and cancer recurrence. Understanding the molecular events that cause radioresistance in PCa will enable us to develop adjuvant treatments for enhancing the efficacy of RT. Radioresistant PCa depends on the elevated DNA repair system and the intracellular levels of reactive oxygen species (ROS) to proliferate, self-renew, and scavenge anti-cancer regimens, whereas the elevated heat shock protein 90 (HSP90) and the epithelial-mesenchymal transition (EMT) enable radioresistant PCa cells to metastasize after exposure to radiation. The up-regulation of the DNA repairing system, ROS, HSP90, and EMT effectors has been studied extensively, but not targeted by adjuvant therapy of radioresistant PCa. Here, we emphasize the effects of ionizing radiation and the mechanisms driving the emergence of radioresistant PCa. We also address the markers of radioresistance, the gene signatures for the predictive response to radiotherapy, and novel therapeutic platforms for targeting radioresistant PCa. This review provides significant insights into enhancing the current knowledge and the understanding toward optimization of these markers for the treatment of radioresistant PCa.