On the Relationship between MMA Levels in Blood Products and Donor Sex, Age, and Donation Frequency.

As the aging process accelerates, the age structure of blood donors turns to older and even aged groups. Methylmalonic acid (MMA), a byproduct of propionate metabolism, may be upregulated in the serum of older adults. As a mediator of chronic disease and tumor progression, the MMA content in blood products has become the focus of research. Absolute concentrations of MMA in blood products were determined based on the liquid chromatography-tandem mass spectrometry, so as to analyze how they were affected by donors' age, sex, and frequency of blood donation. The MMA content in leukocyte-depleted suspended red blood cell (lds-RBC) was significantly higher than that in fresh plasma (p<0.0001). The MMA content among five age groups showed no difference in either fresh plasma or lds-RBCs. The MMA content in fresh plasma was similar in the parameters of the sex, whereas that in lds-RBCs was higher in males than that in females (p=0.035). There were no significant differences in MMA content when it comes to different frequencies of blood donors in either fresh plasma or lds-RBCs. Additionally, there was no significant difference or clear trend in the rate of elevated plasma MMA levels among different sexes, age groups, and blood donation frequency groups. MMA in the blood products from donors in China does not compromise the safety of blood transfusions for cancer patients. Nevertheless, there is a need to focus on MMA levels in Chinese and to develop race-specific and age-specific normal reference ranges.

Transarterial chemoembolization (TACE) plus tyrosine kinase inhibitors versus TACE in patients with hepatocellular carcinoma: a systematic review and meta-analysis.

PURPOSE: Transarterial chemoembolization (TACE) with tyrosine kinase inhibitors (TKIs) has been increasingly used to treat unresectable hepatocellular carcinoma (uHCC). However, the superiority of combination therapy to TACE monotherapy remains controversial. Therefore, here we performed a meta-analysis to evaluate the efficacy and safety of TACE plus TKIs in patients with uHCC. METHODS: We searched four databases for eligible studies. The primary outcome was time to progression (TTP), while the secondary outcomes were overall survival (OS), tumor response rates, and adverse events (AEs). Pooled hazard ratios (HRs) with 95% confidence intervals (95% CIs) were collected for TTP and OS, and the data were analyzed using random-effects meta-analysis models in STATA software. OR and 95% CIs were used to estimate dichotomous variables (complete remission[CR], partial remission[PR], stable disease[SD], progressive disease[PD], objective response rate[ORR], disease control rate[DCR], and AEs) using RStudio's random-effects model. Quality assessments were performed using the Newcastle-Ottawa scale (NOS) for observational studies and the Cochrane risk of bias tool for randomized controlled trials (RCTs). RESULTS: The meta-analysis included 30 studies (9 RCTs, 21 observational studies) with 8246 patients. We judged the risk of bias as low in 44.4% (4/9) of the RCTs and high in 55.6% (5/9) of the RCTs. All observational studies were considered of high quality, with a NOS score of at least 6. Compared with TACE alone or TACE plus placebo, TACE combined with TKIs was superior in prolonging TTP (combined HR 0.72, 95% CI 0.65-0.80), OS (combined HR 0.57, 95% CI 0.49-0.67), and objective response rate (OR 2.13, 95% CI 1.23-3.67) in patients with uHCC. However, TACE plus TKIs caused a higher incidence of AEs, especially hand-foot skin reactions (OR 87.17%, 95%CI 42.88-177.23), diarrhea (OR 18.13%, 95%CI 9.32-35.27), and hypertension (OR 12.24%, 95%CI 5.89-25.42). CONCLUSIONS: Our meta-analysis found that TACE plus TKIs may be beneficial for patients with uHCC in terms of TTP, OS, and tumor response rates. However, combination therapy is also associated with a significantly increased risk of adverse reactions. Therefore, we must evaluate the clinical benefits and risks of combination therapy. Further well-designed RCTs are needed to confirm our findings. TRIAL REGISTRATION: PROSPERO registration number: CRD42022298003.

Azoreductase-Responsive Metal-Organic Framework-Based Nanodrug for Enhanced Cancer Therapy via Breaking Hypoxia-induced Chemoresistance.

The insufficient oxygen supply may cause hypoxia in a solid tumor, which can lead to drug resistance and unsatisfactory chemotherapy effect. To address this issue, a new nanodrug has been developed with azoreductase-responsive functional metal-organic frameworks (AMOFs), where chemotherapeutic drugs were encapsulated in the AMOFs and small interfering RNAs (siRNAs) were absorbed on the surface of AMOFs. The siRNA was designed to contain hypoxia-inducible factor (HIF)-1α against RX-0047, which can induce significant downregulation of HIF-1α protein. The azobenzene units within the frameworks of AMOFs could be reduced to amines by the highly expressed azoreductase under the oxygen-deficient environment, which results in azoreductase-responsive release of the encapsulated drugs and siRNAs under the hypoxic condition. Therefore, once the drug-loaded AMOF entered the hypoxic cancer cells, the azoreductase-responsive release of siRNA could decrease the efflux of chemotherapeutic drugs via inhibiting the expressions of HIF-1α, multidrug resistance gene 1, and P-glycoprotein. This nanodrug can thus efficiently break hypoxia-induced chemoresistance and result in high-efficient cancer therapy in hypoxic tumors. As far as we know, this is the first attempt to construct an AMOF-based nanodrug with hypoxic harvesting behaviors. This proof-of-concept research provides a simple strategy for the construction of hypoxic-responsive AMOFs and also offers a unique on-command drug delivery platform, which can effectively break hypoxia-induced chemoresistance.

Highly selective imaging of lysosomal azoreductase under hypoxia using pH-regulated and target-activated fluorescent nanoprobes.

In this work, we propose a pH-regulated and target-activated fluorescent nanoprobe for highly selective monitoring of lysosomal azoreductase under hypoxia in living cells. We expect it will offer a potentially rich opportunity to understand the physiological processes of lysosomes under hypoxic conditions.

Azoreductase-Responsive Nanoprobe for Hypoxia-Induced Mitophagy Imaging.

Mitophagy, as a crucial metabolic process, plays an essential role in maintaining cellular and tissue homeostasis. Various stresses especially hypoxia could improve intracellular reactive oxygen species (ROS) level to induce mitophagy. However, high-specific fluorescence imaging of mitophagy in living cells under hypoxia is still a challenge. Based on this, we report an azoreductase-responsive nanoprobe (termed Micelle@Mito-rHP@TATp, MCM@TATp) by encapsulating cationic spiropyrane derivative (Mito-rHP) to realize specific imaging of mitophagy in living cells under hypoxia. An azoreductase-responsive amphiphilic polymer, 1,2-distearoyl- sn-glycero-3-phosphoethanolamine-azo- N-[maleimide(polyethylene glycol-2000) (Mal-PEG2000-Azo-DSPE), was first self-assembled into a micelle in aqueous solution. Meanwhile, the synthetic Mito-rHP encapsulated into this formed micelle to construct MCM. By modifying the surface of MCM with cell-penetrating peptide (TATp) to form MCM@TATp, the nanoprobe could avoid endolysosomal trapping. Under hypoxic conditions, the azobenzene moiety-contained MCM@TATp would be disrupted by the highly expressed azoreductase, then the encapsulated Mito-rHP would be released. Since Mito-rHP is a mitochondria-targeted and pH-sensitive probe, thus it could target into mitochondria and displayed a desirable "off-on" fluorescence response to mitophagy during which mitochondria were regarded to undergo acidification. The results indicated that the MCM@TATp in our design could image mitophagy under hypoxia in high-specificity. As further application, we have also demonstrated that this MCM@TATp can perform well to realize mitophagy imaging under the photodynamic therapy (PDT) which can induce hypoxia in treatment of cancer. We expect this new strategy would be a powerful tool for hypoxia-related fundamental and clinical research.

Azoreductase and Target Simultaneously Activated Fluorescent Monitoring for Cytochrome c Release under Hypoxia.

Hypoxia-induced cell apoptosis is closely related to degenerative diseases, autoimmune disorders, and tumor disease. In the process of apoptosis, the release of cytochrome c (Cyt c) is deemed to be a critical factor of the intrinsic pathway. Strategies for tracking Cyt c release in living cells based on the subcellular localization have been proposed recently. However, they are inherently lack of specificity for distinguishing the release of Cyt c in apoptotic process induced by hypoxia from other stimulus. In this paper, an azoreductase and target simultaneously activated fluorescent aptameric nanosensor integrating gold nanoparticles (AuNPs) and Cyt c-targeted aptamer-consisted double-stranded DNA hybridization complex (DSDHC) was proposed. It is worth noting that the employment of azobenzene moiety labeled on the DSDHC first ensured the aptameric nanosensor could be conjugated to the surface of AuNPs and then specifically reduced by hypoxia-related azoreductase. Upon Cyt c released from mitochondrion under hypoxia, the competitive displacement of Cyt c subsequently activated the fluorescence of the aptameric nanosensor and the fluorescence enhancement depended principally on the content of Cyt c release. Inspired by this, a new strategy for quantitative analysis and in situ imaging of Cyt c under hypoxic condition was proposed. The high spatial resolution monitoring of the dynamics of Cyt c release under hypoxia will offer a potentially rich opportunity to understand the apoptotic mechanism under hypoxic conditions, thus further facilitating risk assessment and risk reduction for hypoxic environments.

Hypoxia-triggered gene therapy: a new drug delivery system to utilize photodynamic-induced hypoxia for synergistic cancer therapy.

The therapeutic effects of photodynamic therapy (PDT) are limited by cancer hypoxia because the PDT process is dependent on O2 concentration. Based on this, a new living drug delivery system integrated PDT and hypoxia-triggered gene therapy is proposed, which is made up of three primary constituents: hypoxia-induced cleaved azobenzene (Azo) bridges, HIF-1α-against antisense oligonucleotide (ASO)/G4-constituted double-stranded DNA/RNA hybridization complex (DRHC) and the photosensitizer TMPyP4. During PDT, the continuous consumption of oxygen could remarkably facilitate an intracellular low-oxygen microenvironment. Then, the hypoxia-responsive Azo bridges were reduced by the highly expressed reductases to amines under the oxygen-deficient environment, resulting in a hypoxia-triggered ASO release and providing a synergistic therapy with PDT for suppression of tumor growth. This new drug delivery system opens a new avenue for the design and fabrication of smart drug delivery methods, which can deliver and release drugs according to the specific biological microenvironment in the body.

Quantitative detection of exosomal microRNA extracted from human blood based on surface-enhanced Raman scattering.

Since the nature of the exosomal lipid bilayer can allow miRNAs to be protected from degradation by cellular RNAses in body fluids, exosomal microRNA (miRNA) has become an ideal source of non-invasive biomarkers for the early diagnosis and prognosis. In this paper, a new surface-enhanced Raman scattering (SERS) analysis strategy combining stable SERS reporter element and duplex-specific nuclease (DSN)-assisted signal amplification for quantitative detection of exosomal miRNA extracted from human blood is proposed. Firstly, we prepared SERS signal reporter of Au@R6G@AgAu nanoparticles (R6G attachment on the gold nanoparticles, then encapsulated in AgAu alloy shell nanoparticles named as ARANPs) with an inter small nanogap to generate stable SERS signal. Then, ARANPs and separating substrate of silicon microbead (SiMB) were then covalently attached to the 3'- and 5'- end of capture probe (CP) targeting exosomal miRNA. Upon target miRNA binding, DNA in heteroduplexes could be specifically cleaved by DSN and resulted in the release of ARANPs from the surface of SiMB. Meanwhile, target miRNA remained intact and subsequently involved in the next round of target-recycling amplification. The combination of stable SERS intensity and signal amplification significantly improved the sensitivity of the sensing systems, resulting in detection limits of 5 fM. More importantly, this method also could be used for the detection of exosomal miRNAs extracted from the blood collected from patients of recurrence in non-small-cell lung cancer (NSCLC), with a detection of 5.0µL of sample volume, which has potential for point-of-care testing (POCT) in clinical analysis.

Targeting intracellular oncoproteins with antibody therapy or vaccination.

Antibody-based therapies have better specificity and thus improved efficacy over standard chemotherapy regimens, which result in extended survival and improved quality of life for cancer patients. Because antibodies are viewed as too large to access intracellular locations, antibody therapy has traditionally targeted extracellular or secreted proteins expressed by cancer cells. However, many oncogenic proteins are found within the cell (such as intracellular phosphatases/kinases and transcription factors) and have therefore not been pursued for antibody therapies. Here, we explored the possibility of antibody therapy or vaccination against intracellular proteins. As proofs of concept, we selected three representative intracellular proteins as immunogens for tumor vaccine studies: PRL-3 (phosphatase of regenerating liver 3), a cancer-associated phosphatase; EGFP (enhanced green fluorescent protein), a general reporter; and mT (polyomavirus middle T), the polyomavirus middle T oncoprotein. A variety of tumors that expressed these intracellular proteins were clearly inhibited by their respective exogenous antibodies or by antigen-induced host antibodies (vaccination). These anticancer activities were reproducibly observed in hundreds of C57BL/6 tumor-bearing mice and MMTV-PymT transgenic breast tumor mice. Our in vivo data suggest that immunotherapies can target not only extracellular but also intracellular oncoproteins.

The Hippo pathway in biological control and cancer development.

The Hippo pathway is an evolutionally conserved protein kinase cascade involved in regulating organ size in vivo and cell contact inhibition in vitro by governing cell proliferation and apoptosis. Deregulation of the Hippo pathway is linked to cancer development. Its first core kinase Warts was identified in Drosophila more than 15 years ago, but it gained much attention when other core components of the pathway were identified 8 years later. Major discoveries of the pathway were made during past several years. The core kinase components Hippo, Salvador, Warts, and Mats in the fly and Mst1/2, WW45, Lats1/2, and Mob1 in mammals phosphorylate and inactivate downstream transcriptional co-activators Yorkie in the fly, Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) in mammals, respectively. Phosphorylated Yorkie, YAP, and TAZ are sequestered in the cytoplasm by interaction with 14-3-3 proteins. Here we review recent progresses of this pathway by focusing on how these proteins communicate with each other and how loss of regulation results in cancers.

TEADs mediate nuclear retention of TAZ to promote oncogenic transformation.

The transcriptional coactivators YAP and TAZ are downstream targets inhibited by the Hippo tumor suppressor pathway. The expression level of TAZ is recently shown to be elevated in invasive breast cancer cells and some primary breast cancers. TAZ is important for breast cancer cell migration, invasion, and tumorigenesis, but the underlying mechanism is not defined. In this study, we show that TAZ interacts with TEAD transcriptional factors. Knockdown of TEADs suppresses TAZ-mediated oncogenic transformation of MCF10A cells. Uncoupling TAZ from Hippo regulation by S89A mutation enhances its transforming ability. Several residues located in the N-terminal region of TAZ are identified to be important for interaction with TEADs, and these same residues are equally important for TAZ to transform MCF10A cells. Mechanistically, TAZ mutants defective in interaction with TEADs fail to accumulate in the nucleus. Live cell imaging of enhanced green fluorescent protein-TAZ and its mutant defective in TEAD interaction suggests that TEAD interaction mediates nuclear retention. These results reveal a novel mechanism for TEADs to regulate nuclear retention and thus the transforming ability of TAZ.