Preoperative Radiotherapy Decision-Tree for Rectal Cancer Patients: A Real-World Analysis Based on the Swedish Colorectal Cancer Registry.

BACKGROUND: There are 3 widely used preoperative radiotherapy (RT) procedures in rectal cancer treatment including long-course RT (LRT), short-course RT with delayed surgery (SRTW), and short-course RT with immediate surgery (SRT). However, further evidence is required to determine which treatment option results in more optimal patient survival. METHODS: This Swedish Colorectal Cancer Registry-based retrospective study of real-world data included 7766 stage I-III rectal cancer patients, of which 2982, 1089, 763, and 2932 patients received no RT (NRT), LRT, SRTW, and SRT, respectively. The Kaplan-Meier survival curve and Cox proportional hazard multivariate model were used to identify potential risk factors and to examine the independent association of RT with patient survival after adjusting for baseline confounding factors. RESULTS: RT effects on survival differed by age and clinical T stage (cT) subgroups. Subsequent survival analysis by age and cT subgroups confirmed that patients ≥70 years old with cT4 benefited from any RT (P < .001, NRT as reference) and equally from any RT (P > .05 pairwise between RTs). In contrast, for cT3 patients ≥70 years, SRT and LRT were associated with better survival than SRTW (P < .001). In patients <70 years, LRT and SRTW had superior survival benefits in cT4 patients but inferior to SRT (P < .001); SRT was the only effective treatment in the cT3N+ subgroup (P = .032); patients with cT3N0 and <70 years did not benefit from any RT. CONCLUSION: This study suggests that preoperative RT strategies may have varying effects on the survival of rectal cancer patients, depending on their age and clinical stage.

APR-246 Enhances Colorectal Cancer Sensitivity to Radiotherapy.

p53 mutation is common and highly related to radiotherapy resistance in rectal cancer. APR-246, as a small molecule, can restore the tumor-suppressor function to mutant p53. As there is currently no existing study on combining APR-246 with radiation in rectal cancer, our objective was to investigate whether APR-246 could enhance the sensitivity of colorectal cancer cells, regardless of their p53 status, to radiation treatment. The combination treatment had synergistic effects on HCT116p53-R248W/- (p53Mut) cells, followed by HCT116p53+/+ [wild-type p53 (p53WT)] cells, and exhibited an additive effect on HCT116p53-/- (p53Null) cells through inhibiting proliferation, enhancing reactive oxygen species, and apoptosis. The results were confirmed in zebrafish xenografts. Mechanistically, p53Mut and p53WT cells shared more activated pathways and differentially expressed genes following the combination treatment, compared with p53Null cells, although the combination treatment regulated individual pathways in the different cell lines. APR-246 mediated radiosensitization effects through p53-dependent and -independent ways. The results may provide evidence for a clinical trial of the combination in patients with rectal cancer.

Using Cellulose Nanocrystal as Adjuvant to Improve the Dispersion Ability of Multilayer Graphene in Aqueous Suspension.

Cellulose nanocrystal (CNC) has been applied in various fields due to its nano-structure, high aspect ratio, specific surface area and modulus, and abundance of hydroxy groups. In this work, CNC suspensions with different concentrations (0.4, 0.6, and 0.8%) were used as the adjuvant to improve the dispersion ability of multilayer graphene (MLG) in aqueous suspension, which is easy to be aggregated by van der Waals force between layers. In addition, N-methyl-2-pyrrolidone, ethanol, and ultrapure water were used as control groups. Zeta potential analysis and Fourier transform infrared spectroscopy showed that the stability of MLG/CNC has met the requirement, and the combination of CNC and MLG was stable in aqueous suspension. Results from transmission electron microscopy, Fourier transform infrared spectroscopy, and absorbance showed that MLG had a better dispersion performance in CNC suspensions, compared to the other solutions. Raman spectrum analysis showed that the mixtures of 1.0 wt% MLG with 0.4% CNC had the least defects and fewer layers of MLG. In addition, it is found that CNC suspension with 0.8% concentration showed the highest ability to disperse 1.0 wt% MLG with the most stable performance in suspension. Overall, this work proved the potential application of CNC as adjuvant in the field of graphene nanomaterials.

The bromodomain and extra-terminal domain inhibitor JQ1 synergistically sensitizes human colorectal cancer cells to topoisomerase I inhibitors through repression of Mre11-mediated DNA repair pathway.

Camptothecin (CPT) and its derivatives, irinotecan and topotecan are specific topoisomerase I (Top1) inhibitors and potent anticancer drugs. Mechanistically, they induce DNA double-strand breaks (DSBs). Although CPT is an effective chemotherapeutic agent used in the management of advanced colorectal cancer, there exist associated side effects. Herein, we aimed to establish novel drug combinations that can effectively aid in managing the CPT-related side effects. Besides, bromodomain and extra-terminal domain (BET) inhibitors have proved as promising drugs that target epigenetic mechanisms in various cancers, they alter DNA repair processes, hence are a potential candidate for CPT synthetic lethality. A novel BET inhibitor JQ1 synergized with CPT, exerted antiproliferative effects. Through cell cycle analyses and apoptosis assays, we revealed that a combination of CPT and JQ1 induces subG1-phase arrest and enhances cell apoptosis. This combination increased the intensity of γ-H2AX staining, a specific marker of DSBs. Moreover, colorectal cancer cells highly expressing Top1 showed greater sensitivity to JQ1, which was lowered through the lentiviral shRNA-mediated knockdown of Top1. JQ1, combined with CPT, impeded the recruitment of the Mre11-mediated MRN complex. Finally, JQ1 enhanced the in vivo sensitivity of tumors to CPT without inducing toxicity. These results demonstrate that a combination of BET inhibitor with Top1 inhibitor is safe and exerts positive chemotherapeutic effects in colorectal cancer.

Sandcastle worm-inspired phytic acid and magnesium oxychloride cement copolymerization for performance enhancement.

The development of magnesium oxychloride cement (MOC) can convert wastes in the potash industry into valuable products and reduce CO2 emission. The use of acid radicals has the potential to enhance the water resistance of MOC. However, because of the internal stress formed during the crystallization process, the occurrence of cracks accompanied by a significant decrease in the mechanical properties is inevitable. Inspired by the sandcastle worm and organic-inorganic copolymerization, a novel strategy was proposed, which employed phytic acid (PA) to copolymerize with phase 5 crystals to reduce the internal stress and prevent crack generation. XPS and TG-DSC analyses revealed that organic-inorganic copolymers were successfully produced. Furthermore, the compressive strength (CS) and water resistance of MOC-PA were significantly enhanced. The enhanced properties were associated with the coordination bonds and high tension of the rigid rings in phytic acid, which was sufficient to overcome the internal stress. Additionally, the repeated hydrolysis of rod-like phase 5 generated a gel-like phase from the outside inward, enhancing their water resistance. Compared with MOC-0, MOC-0.6 showed a 17.8% increase in CS and a 102.3% increase in water resistance. The microscopic mechanisms of the enhanced CS and water resistance of high-performance greener cements were proposed.

miR-124 Intensified Oxaliplatin-Based Chemotherapy by Targeting CAPN2 in Colorectal Cancer.

Our previous study demonstrated that miR-124 was downregulated in colorectal cancer (CRC) compared with normal mucosa, and the downregulated expression of miR-124 was an independent prognostic factor in CRC patients. However, the function of miR-124 in CRC patients treated with chemotherapy is currently unclear. The aim of this study was to determine the miR-124 expression and its regulative role in oxaliplatin (L-OHP)-based chemotherapy of CRC patients. We observed that low miR-124 expression was correlated with worse overall survival (OS) in the 220 patients who received postoperative chemotherapy of 5-fluorouracil [5-FU]+leucovorin+L-OHP (FOLFOX) or capecitabine+L-OHP (XELOX). miR-124 overexpression promoted L-OHP-induced, but not 5-FU-induced, cytotoxicity and apoptosis in HT29 and SW480 cells. CAPN2 was a direct target of miR-124, and its protein expression was reduced by forced expression of miR-124. miR-124 inhibited tumorigenesis and promoted OS of mice bearing xenograft tumors, especially upon L-OHP treatment. miR-124 also promoted L-OHP-induced apoptosis and restrained CAPN2 protein expression in xenograft tumors. Our results suggest that miR-124 could be considered as both a predictor of L-OHP-based chemotherapy for personalized treatment and a therapeutic target for CRC.

Effect of Phenol Formaldehyde Resin Penetration on the Quasi-Static and Dynamic Mechanics of Wood Cell Walls Using Nanoindentation.

To evaluate the effects of phenol formaldehyde (PF) resin modification on wood cell walls, Masson pine (Pinus massoniana Lamb.) wood was impregnated with PF resin at the concentrations of 15%, 20%, 25%, and 30%, respectively. The penetration degree of PF resin into wood tracheids was quantitatively determined using confocal laser scanning microscopy (CLSM). The micromechanical properties of the control and PF-modified wood cell walls were then analyzed by the method of quasi-static nanoindentation and dynamic modulus mapping techniques. Results indicated that PF resin with low molecular weight can penetrate deeply into the wood tissues and even into the cell walls. However, the penetration degree decreased accompanying with the increase of penetration depth in wood. Both the quasi-static and dynamic mechanics of wood cell walls increased significantly after modification by the PF resin at the concentration less than 20%. The cell-wall mechanics maintained stable and even decreased as the resin concentration was increased above 20%, resulting from the increasing bulking effects such as the decreased crystallinity degree of cellulose. Furthermore, the mechanics of cell walls in the inner layer was lower than that in the outer layer of PF-modified wood.

Heterogeneous nuclear ribonucleoprotein L facilitates recruitment of 53BP1 and BRCA1 at the DNA break sites induced by oxaliplatin in colorectal cancer.

Although oxaliplatin is an effective chemotherapeutic drug for treatment of colorectal cancer (CRC), tumor cells can develop mechanisms to evade oxaliplatin-induced cell death and show high tolerance and acquired resistance to this drug. Heterogeneous nuclear ribonucleoprotein L (hnRNP L) has been proved to play a critical role in DNA repair during IgH class switch recombination (CSR) in B lymphocytes, while, its role in CRC and chemotherapeutic resistance remain unknown. Our study aims to uncover an unidentified mechanism of regulating DNA double-strand breaks (DSBs) by hnRNP L in CRC cells treated by oxaliplatin. In present study, we observed that knockdown of hnRNP L enhanced the level of DNA breakage and sensitivity of CRC cells to oxaliplatin. The expression of key DNA repair factors (BRCA1, 53BP1, and ATM) was unaffected by hnRNP L knockdown, thereby excluding the likelihood of hnRNP L mediation via mRNA regulation. Moreover, we observed that phosphorylation level of ATM changed oppositely to 53BP1 and BRCA1 in the CRC cells (SW620 and HCT116) which exhibit synergistic effect by oxaliplatin plus hnRNP L impairment. And similar phenomenon was observed in the foci formation of these critical repair factors. We also found that hnRNP L binds directly with these DNA repair factors through its RNA-recognition motifs (RRMs). Analysis of cell death indicated that the RRMs of hnRNP L are required for cell survival under incubation with oxaliplatin. In conclusion, hnRNP L is critical for the recruitment of the DNA repair factors in oxaliplatin-induced DSBs. Targeting hnRNP L is a promising new clinical approach that could enhance the effectiveness of current chemotherapeutic treatment in patients with resistance to oxaliplatin.

Cell-based therapy for acute and chronic liver failures: distinct diseases, different choices.

Cell-based therapies (CBTs) are considered the effective approaches to treat liver failure. However, which cell type is the most suitable source of CBTs for acute liver failure (ALF) or chronic liver failure (CLF) remains unclear. To investigate this, mature hepatocytes in adult liver (adult HCs), fetal liver cells (FLCs), induced hepatic stem cells (iHepSCs) and bone marrow derived mesenchymal stromal cells (BMSCs) were used to CBTs for ConA-induced ALF and Fah-deficient induced CLF in mice. The results showed that only BMSCs remitted liver damage and rescued ALF in ConA-treated mice. In this process, BMSCs inhibited ConA-induced inflammatory response by decreasing the mRNA expressions of TNF-α, IFN-γ and FasL and increasing IL-10 mRNA expression. However, in the CLF model, not BMSCs but adult HCs transplantation lessened liver injury, recovered liver function and rescued the life of Fah-/- mice after NTBC withdrawal. Further study showed that adult HCs offered more effective liver regeneration compared to other cells in Fah-/- mice without NTBC. These results demonstrated that BMSCs and adult HCs are the optimal sources of CBTs for ConA-induced ALF and Fah-deficient induced CLF in mice, respectively. This finding deepens our understanding about how to select a proper CBT for different liver failure.

Autophagy contributes to the survival of CD133+ liver cancer stem cells in the hypoxic and nutrient-deprived tumor microenvironment.

Liver cancer stem cells (LCSCs) can drive and maintain hepatocellular carcinoma (HCC) growth, metastasis, and recurrence. Therefore, they are potentially responsible for the poor prognosis of HCC. Oxygen and nutrient deficiencies are common characteristics of the tumor microenvironment. However, how LCSCs adapt to oxygen- and nutrient-deprived conditions is unclear. Here, we used immunofluorescent staining and flow cytometry analysis to show that CD133+ cells were significantly enriched after hypoxia and nutrient starvation (H/S) in the human HCC cell line Huh7. Sorted CD133+ cells showed higher survival, less apoptosis, and possess higher clonogenic ability under H/S compared to the CD133- population. Under H/S, electron microscopy revealed more advanced autophagic vesicles in CD133+ cells. Additionally, CD133+ cells had higher autophagy levels as measured by both RT-qPCR and Western blotting. CD133+ cells had more accumulated GFP-LC3 puncta, which can be detected by fluorescence microscopy. The autophagic inhibitor chloroquine (CQ) significantly increased apoptosis and decreased the clonogenic capacity of CD133+ cells under H/S. Pre-culturing in H/S enhanced the sphere-forming capacity of CD133+ cells. However, CQ significantly impaired this process. Therefore, autophagy is essential for LCSCs maintenance. CD133+ cells were also found to have a higher tumor-forming ability in vivo, which could be inhibited by CQ administration. Collectively, our results indicate that the involvement of autophagy in maintenance of CD133+ LCSCs under the oxygen- and nutrient-deprived conditions that are typical of the tumor microenvironment in HCC. Therefore, autophagy inhibitors may make LCSCs more sensitive to the tumor microenvironment and be useful in improving anti-cancer treatments.

Autophagy lessens ischemic liver injury by reducing oxidative damage.

BACKGROUND: Hepatic ischemia/reperfusion is a multi-factorial process which causes liver injury. It is reported that ischemia alone is sufficient to induce liver injury. Nutrient deprivation is a crucial factor impacting ischemic injury of the liver. Therefore, we explored the role of autophagy in ischemia through using hepatic ischemia rat model in vivo and nutrient-free model in vitro. RESULTS: We found that both ischemia in vivo and nutrient deprivation in vitro activated autophagy, inhibition of which aggravated ischemia- or nutrient deficiency-induced injury. In the nutrient-free condition, autophagy inhibition enhanced liver cell necrosis but not apoptosis by promoting reactive oxygen species (ROS) accumulation, and antioxidant NAC could reverse this trend. Inhibition of autophagy also resulted in the increase of the percentage of necrotic cell but not apoptotic cell in the ischemia-treated rat livers. Further studies showed that under nutrient deprivation, autophagy inhibition promoted mitochondrial ROS generation, which further aggravated mitochondria damage. These changes formed a "vicious cycle" that accelerated the process of cell necrosis. Autophagy inhibition also increased mitochondrial oxidative stress during hepatic ischemia, and antioxidant could suppress the aggravation of ischemia-induced liver damage in the co-treatment of autophagy inhibitor. CONCLUSIONS: Taken together, our results suggested that autophagy suppressed ischemic liver injury by reducing ROS-induced necrosis. This finding will contribute to the development of the therapeutic strategy about the pre-treatment of liver surgery.

p53-mediated autophagy adjustment is involved in the protection of silibinin against murine dermal inflammation and epidermal apoptosis induced by UVB irradiation.

Apoptosis in murine dermal cells is retarded by ultraviolet B (UVB) irradiation-induced autophagic intervention while simultaneously epidermal cells commit apoptosis, during which inflammatory cytokines released from the lost epidermal cells promote immune responses of dermal inflammatory cells, forming morphological symptoms of acute cutaneous diseases. Autophagy is involved in prevention or provocation of apoptosis of dermal or epidermal cells of UVB-irradiated mice via modulation of intracellular metabolism, intervening the balance between cell death and survival in dermis and epidermis. p53 expressed in immune system affects autophagy function through activating or inactivating genes encoding apoptotic factors and inflammatory cytokines. Silibinin protects dermal and epidermal cells of UVB irradiated skin against abnormally autophagy-mediated apoptosis adjustments. In this study, how UVB irradiation intervenes autophagy in dermal and epidermal cells as well as how silibinin protects UVB irradiated skin through physiological recovering of autophagy function in dermis and epidermis are focused and elucidated preliminarily. Silibinin treatment (50 mg/kg/day for 4 days) reversed dermal and epidermal autophagy levels from UVB irradiation-induced improper autophagy intervention, repaired the balance between cell survival and death in dermis and epidermis, and protected skin against damage through mediation of p53 activation in dermal and epidermal cells.

[Rapid identification of softwood and hardwood by near infrared spectroscopy of cross-sectional surfaces].

The feasibility of wood identification of softwood and hardwood by near infrared spectroscopy (NIR) coupled with partial least squares discriminant analysis (PLS-DA) was investigated in the present paper. The near infrared spectra (780 - 2 500 nm) were collected from wood cross-section from one softwood species (Chinese fir) and one hardwood species (eucalyptus). The results show that: (1) The identification accuracy of the calibration samples predicted by the model based on NIR coupled the PLS-DA was 100%. The correlation coefficient between the NIR predicted category variable value and the true value was 0.990, and the SEC was 0.071; (2) The identification accuracy by the model based on the spectra with 780-1 100 nm wavelengths also was 100%, and the correlation coefficient and SEC were 0. 990 and 0. 070, respectively; (3) The identification accuracy for the test samples was 100%. It was suggested that NIR can be used to rapidly and accurately identify softwood and hardwood samples. It also provides a new approach to identifying wood species.

Targeting autophagy potentiates chemotherapy-induced apoptosis and proliferation inhibition in hepatocarcinoma cells.

Induction of cell death and inhibition of cell growth are the main targets of cancer therapy. Here we evaluated the role of autophagy on chemoresistance of human hepatocarcinoma (HCC) cell lines, focusing on its crosstalk with cell apoptosis and proliferation. In this study, a chemotherapeutic agent (cisplatin or 5FU) induced the formation of autophagosomes in three human HCC cell lines and upregulated the expression of autophagy protein LC3-II. Inhibition of autophagy by 3-methyladenine or si-beclin 1 increased chemotherapy-induced apoptosis in HCC cells. Meanwhile, increased damage of the mitochondrial membrane potential was also observed in HCC cells when autophagy was inhibited. Furthermore, inhibition of autophagy reduced clone formation and impaired cell growth of HCC cells when treated with chemotherapy. Co-administration of an autophagy inhibitor (chloroquine) and chemotherapy significantly inhibited tumor growth in a mouse xenograft tumor model, with greater extent of apoptosis and impaired proliferation of tumor cells. This study suggests that autophagy is a potential novel target to improve therapy efficiency of conventional chemotherapeutics towards HCC.

Autophagy in hypoxia protects cancer cells against apoptosis induced by nutrient deprivation through a Beclin1-dependent way in hepatocellular carcinoma.

Oxygen deficiency and nutrient deprivation widely exists in solid tumors because of the poor blood supply. However, cancer cells can survive this adverse condition and proliferate continuously to develop. To figure out the way to survive, we investigated the role of autophagy in the microenvironment in hepatocellular carcinoma. In order to simulate the tumor microenvironment more veritably, cells were cultured in oxygen-nutrient-deprived condition following a hypoxia preconditioning. As a result, cell death under hypoxia plus nutrient deprivation was much less than that under nutrient deprivation only. And the decreased cell death mainly attributed to the decreased apoptosis. GFP-LC3 and electron microscopy analysis showed that autophagy was significantly activated in the period of hypoxia preconditioning. However, autophagic inhibitor-3-MA significantly abrogated the apoptosis reduction in hypoxia, which implied the involvement of autophagy in protection of hepatocellular carcinoma cells against apoptosis induced by starvation. Furthermore, Beclin 1 was proved to play an important role in this process. siRNA targeting Beclin 1 was transfected into hepatocellular carcinoma cells. And both data from western blot detecting the expression of LC3-II and transmission microscopy observing the accumulation of autophagosomes showed that autophagy was inhibited obviously as a result of Beclin 1 knockdown. Besides, the decreased apoptosis of starved cells under hypoxia was reversed. Taken together, these results suggest that autophagy activated by hypoxia mediates the tolerance of hepatocellular carcinoma cells to nutrient deprivation, and this tolerance is dependent on the activity of Beclin 1.