Exosomes in Cancer Diagnosis and Radiation Therapy

Exosomes are a subgroup of extracellular vesicles that are released by all types of cells, including tumor cells, and mediate intercellular communication via the transport of various intracellular components, including microRNAs, messenger RNAs, and proteins. Radiation produces reactive oxygen species and induces DNA double-strand break in cancer cells and normal cells. Cancer cells have severe damage and die by irradiation, but normal cells can keep proliferation with their high DNA repair ability. Irradiated cells generate communication signals and cause biological changes in neighboring or distant non-irradiated cells. This review outlines the role of exosomes in radiation therapy. In the tumor microenvironment, exosomes are considered to regulate cell survival, migration, and resistance to therapy by interacting with vascular endothelial cells and various types of immune cells. Nowadays, radiation therapy is typically combined with immunotherapy. Regulation of the activity of exosomes may overcome the problem of resistance to immunotherapy. Furthermore, exosomes can attenuate resistance to chemotherapy by transporting certain types of microRNA. The current evidence suggests that exosomes may be useful in the diagnosis and treatment of cancer in the future.

Influence of GSTM1, GSTT1, and GSTP1 genetic polymorphisms on disorders in transplant patients: a systematic review

The glutathione-S-transferase (GST) enzymes are phase II isoenzymes responsible for protection against free radicals and xenobiotics. Since these proteins are described as polymorphic, polymorphisms in genes that encode them may alter enzymatic function and contribute to oxidative stress. In this context, such polymorphisms were already associated with several diseases and multiple therapeutic outcomes. A systematic review was performed to evaluate studies regarding the association between polymorphisms in three genes encoding enzymes of the GST family – GSTM1, GSTT1, and GSTP1 – and disorders in transplant patients. A total of 125 articles on which inclusion and exclusion criteria were applied were identified at PubMed database. Thirty-two studies met the target criteria and were included in the review. The mechanisms by which GST genotypes influence the development of disorders in transplant patients differ by disorder: they may participate in it by decreasing metabolism of drugs administered to patients undergoing transplantation, then exposing them to greater toxicity; by decreasing the repair ability against oxidative stress; or by encoding proteins that may be recognized as foreign, setting of an alloimmune reaction. Although some results are better established – such as GSTM1 null genotype’s role in the development of toxicity events in transplant patients – others require further evidences, as GST influence on the development of pulmonary decline and posttransplant diabetes mellitus (PTDM). The importance of investigating these associations lies in a personalized medicine, in which the high-risk genotype patient has its treatment individualized and its care for prophylaxis and surveillance increased, potentially reducing this population’s morbimortality.

Decreased DNA Repair Ability: A Mechanism for Low Early Embryonic Development Potential of Oocytes From Overweight Patients After Fertilization in IVF Cycles

BackgroundWhether female BMI impacts the DNA repair ability in the oocytes after fertilization has not been investigated. The aim of this study is to assess the early embryo quality and reproductive outcomes of oocytes from overweight women when fertilized with sperm with varying degrees of DNA fragmentation.MethodsA total number of 1,612 patients undergoing fresh autologous in vitro fertilization (IVF) cycles was included. These patients were divided into two groups according to maternal body mass index (BMI): normal weight group (18.5–24.9 kg/m2; n=1187; 73.64%) and overweight group (≥25 kg/m2; n=425; 26.36%). Each group was then subdivided into two groups by sperm DNA fragmentation index (DFI): low fragmentation group (<20% DFI, LF) and high fragmentation group (≥20% DFI, HF). Laboratory and clinical outcomes were compared between subgroups.ResultsFor the normal-weight group, there was no statistical significance in embryo quality and reproductive outcomes between the LF and HF groups. But in the overweight group, significantly lower fertilization rate (LF: 64%; HF: 59%; p=0.011), blastocyst development rate (LF: 57%; HF: 44%; p=0.001), as well as high-quality blastocyst rate (LF: 32%; HF: 22%; p=0.034) were found in the HF group, despite the similar pregnancy rates (LF: 56%; HF: 60%; p=0.630).ConclusionsDecreased DNA repair activity in oocytes may be a possible mechanism for the low early development potential of embryos from overweight patients in in vitro fertilization cycles.

High Expression of Cancer-IgG Is Associated With Poor Prognosis and Radioresistance via PI3K/AKT/DNA-PKcs Pathway Regulation in Lung Adenocarcinoma

BackgroundLung adenocarcinoma (LUAD) is the dominant type of lung neoplasms, and radiotherapy is its mainstay treatment, yet poor prognosis caused by radioresistance remains problematic. Cancer-derived immunoglobulin G (cancer-IgG) has been detected in multiple cancers and plays important roles in carcinogenesis. This study aimed to demonstrate that cancer-IgG is associated with poor prognosis of LUAD and to identify its role in radioresistance.MethodsCancer-IgG expression was detected by immunohistochemistry from 56 patients with stage III LUAD and by western blot and immunofluorescence in LUAD cell lines and in a human bronchial epithelial cell line. The effects of cancer-IgG silencing on the proliferation and apoptosis of PC9 and H292 cells were evaluated by plate cloning and apoptosis assay; the effects of cancer-IgG silencing on DNA damage repair ability and radiosensitivity were evaluated by colony-forming assay, γH2AX immunofluorescence, and neutral comet assay. Finally, we used the protein phosphorylation microarray and western blot to explore mechanisms involving cancer-IgG that increased radioresistance.ResultsCancer-IgG is widely expressed in stage III LUAD, and the overall survival and disease-free survival of patients with positive expression are notably lower than those of patients with negative expression, indicating the associations between cancer-IgG and poor prognosis as well as radioresistance. The expression of cancer-IgG in the four LUAD cell lines was located mainly on the cell membrane and cytoplasm and not in the normal lung epithelial cell. Knockdown of cancer-IgG in PC9 and H292 cells resulted in increased apoptosis and negatively affected cancer cell proliferation. After irradiation, silencing of cancer-IgG showed a decrease in colonies as well as increases in the Olive tail moment and γH2AX foci in nucleus, indicating that the knockdown of cancer-IgG resulted in a decrease in the damage repair ability of DNA double-strand breaks in LUAD cells and an enhanced radiosensitivity. The expression of p-AKT, p-GSK3β, and p-DNA-PKcs decreased in the knockdown group after radiotherapy, suggesting that cancer-IgG could affect radiotherapy resistance by mediating double-strand breaks damage repair in LUAD cells through the PI3K/AKT/DNA-PKcs pathway.ConclusionsThis study revealed that cancer-IgG regulates PI3K/AKT/DNA-PKcs signaling pathways to affect radioresistance of LUAD and associated with poor prognosis.

Enhanced wound repair ability of arginine-chitosan nanocomposite membrane through the antimicrobial peptides-loaded polydopamine-modified graphene oxide

Skin wound healing is a complicated and lengthy process, which is influenced by multiple factors and need a suitable cellular micro-environment. For skin wound, wound dressings remain a cornerstone of dermatologic therapy at present. The dressing material can create an effective protective environment for the wound, and the interactions between the dressing and the wound has a great impact on the wound healing efficiency. An ideal wound dressing materials should have good biocompatibility, moisturizing property, antibacterial property and mechanical strength, and can effectively prevent wound infection and promote wound healing. In this study, in order to design wound dressing materials endowed with excellent antibacterial and tissue repair properties, we attempted to load antimicrobial peptides onto dopmine-modified graphene oxide (PDA@GO) using lysozyme (ly) as a model drug. Then, functionalized GO was used to the surface modification of arginine-modified chitosan (CS-Arg) membrane. To evaluate the potential of the prepared nanocomposite membrane in wound dressing application, the surface morphology, hydrophilic, mechanical properties, antimicrobial activity, and cytocompatibility of the resulting nanocomposite membrane were analyzed. The results revealed that prepared nanocomposite membrane exhibited excellent hydrophilic, mechanical strength and antimicrobial activity, which can effectively promote cell growth and adhesion. In particular, using PDA@GO as drug carrier can effectively maintain the activity of antimicrobial peptides, and can maximize the antibacterial properties of the nanocomposite membrane. Finally, we used rat full-thickness wound models to observe wound healing, and the surface interactions between the prepared nanocomposite membrane and the wound. The results indicated that nanocomposite membrane can obviously accelerated wound closure, and the wounds showed reduced inflammation, improved angiogenesis and accelerated re-epithelialization. Therefore, incorporation of antimicrobial peptides-functionalize graphene oxide (ly-PDA@GO) into CS-Arg membrane was a viable strategy for fabricating excellent wound dressing. Together, this study not only prepared a wound dressing with excellent tissue repair ability, but also provided a novel idea for the development of graphene oxide-based antibacterial dressing.

Coping with the calcium overload caused by cell injury: ER to the rescue

Cells maintain their cytosolic calcium (Ca2+) in nanomolar range and use controlled increase in Ca2+ for intracellular signaling. With the extracellular Ca2+ in the millimolar range, there is a steep Ca2+ gradient across the plasma membrane (PM). Thus, injury that damages PM, leads to a cytosolic Ca2+ overload, which helps activate PM repair (PMR) response. However, in order to survive, the cells must cope with the Ca2+ overload. In a recent study (Chandra et al. J Cell Biol,doi: 10.1083/jcb.202006035) we have examined how cells cope with injury-induced cytosolic Ca2+ overload. By monitoring Ca2+ dynamics in the cytosol and endoplasmic reticulum (ER), we found that PM injury-triggered increase in cytosolic Ca2+ is taken up by the ER. Pharmacological inhibition of ER Ca2+ uptake interferes with this process and compromises the repair ability of the injured cells. Muscle cells from patients and mouse model for the muscular dystrophy showed that lack of Anoctamin 5 (ANO5)/Transmembrane protein 16E (TMEM16E), an ER-resident putative Ca2+-activated chloride channel (CaCC), are poor at coping with cytosolic Ca2+ overload. Pharmacological inhibition of CaCC and lack of ANO5, both prevent Ca2+ uptake into ER. These studies identify a requirement of Cl– uptake by the ER in sequestering injury-triggered cytosolic Ca2+ increase in the ER. Further, these studies show that ER helps injured cells cope with Ca2+ overload during PMR, lack of which contributes to muscular dystrophy due to mutations in the ANO5 protein.

Enhanced wound repair ability of arginine-chitosan nanocomposite membrane through the antimicrobial peptides-loaded dopmine-modified graphene oxide

Skin wound healing is a complicated and lengthy process, which is influenced by multiple factors and need a suitable cellular micro-environment. For skin wound, wound dressings remain a cornerstone of dermatologic therapy at present. The dressing material can create an effective protective environment for the wound, and the interactions between the dressing and the wound has a great impact on the wound healing efficiency. An ideal wound dressing materials should have good biocompatibility, moisturizing property, antibacterial property and mechanical strength, and can effectively prevent wound infection and promote wound healing. In this study, in order to design wound dressing materials endowed with excellent antibacterial and tissue repair properties, we attempted to load antimicrobial peptides onto dopmine-modified graphene oxide (PDA@GO) using lysozyme (ly) as a model drug. Then, functionalized GO was used to the surface modification of arginine-modified chitosan (CS-Arg) membrane. To evaluate the potential of the prepared nanocomposite membrane in wound dressing application, the surface morphology, hydrophilic, mechanical properties, antimicrobial activity, and cytocompatibility of the resulting nanocomposite membrane were analyzed. The results revealed that prepared nanocomposite membrane exhibited excellent hydrophilic, mechanical strength and antimicrobial activity, which can effectively promote cell growth and adhesion. In particular, using PDA@GO as drug carrier can effectively maintain the activity of antimicrobial peptides, and can maximize the antibacterial properties of the nanocomposite membrane. Finally, we used rat full-thickness wound models to observe wound healing, and the surface interactions between the prepared nanocomposite membrane and the wound. The results indicates that nanocomposite membrane can obviouly accelerated wound closure, and the wounds showed reduced inflammation, improved angiogenesis and accelerated re-epithelialization. Therefore, incorporation of antimicrobial peptides -functionalize graphene oxide (ly-PDA@GO) into CS-Arg membrane was a viable strategy for fabricating excellent wound dressing. Together, this study not only prepared a wound dressing with excellent tissue repair ability, but also provided a novel idea for the development of graphene oxide-based antibacterial dressing.

CS2164 and Venetoclax Show Synergistic Antitumoral Activities in High Grade B-Cell Lymphomas With MYC and BCL2 Rearrangements

High-grade B-cell lymphoma with concurrent MYC and BCL2 rearrangements (HGBL-DHL) is a rare, aggressive mature B-cell malignancy with a high likelihood of treatment failure following front-line immunochemotherapies. Patients with HGBL-DHL who develop a relapsed or refractory disease have little effective therapeutic strategies and show very poor clinical outcomes, thus calling for development of novel therapies for this specific patient population. In this study, we investigated the preclinical anti-lymphoma efficacies and potential mechanism of action of a novel treatment approach, combining the BCL2 inhibitor venetoclax with CS2164, a new orally active multitarget inhibitor, in HGBL-DHL models. This combination therapy exhibited a robust synergistic cytotoxicity against HGBL-DHL cells, evidenced by cooperatively inducing loss of cell viability and promoting cell apoptosis. Moreover, coadministration of CS2164 and venetoclax resulted in significant superior suppression of HGBL-DHL cell growth and remarkably abrogated tumor burden in a HGBL-DHL-xenografted mouse model. The synergistic lethality of CS2164 and venetoclax in HGBL-DHL cells was associated with induction of DNA damage and impairment of DNA repair ability. Of importance, the combined treatment almost abolished the expression of both BCL2 and MYC, two hallmark proteins of HGBL-DHL, and substantially blunted the activity of PI3K/AKT/mTOR signaling cascade. In addition, MCL1 and BCL-XL, two well-characterized contributors for venetoclax resistance, were significantly lessened in the presence of CS2164 and venetoclax, thus leading to the accumulation of proapoptotic proteins BAX and PUMA and then initiating the intrinsic apoptosis pathway. Taken together, these findings suggest that the regimen of CS2164 and venetoclax is highly effective to eliminate HGBL-DHL cells in the preclinical setting, warranting further clinical investigations of this regimen for the treatment of unfavorable HGBL-DHL patients.