Targeting 4-1BB for tumor immunotherapy from bench to bedside

Immune dysfunction has been proposed as a factor that may contribute to disease progression. Emerging evidence suggests that immunotherapy aims to abolish cancer progression by modulating the balance of the tumor microenvironment. 4-1BB (also known as CD137 and TNFRS9), a member of tumor necrosis factor receptor superfamily, has been validated as an extremely attractive and promising target for immunotherapy due to the upregulated expression in the tumor environment and its involvement in tumor progression. More importantly, 4-1BB-based immunotherapy approaches have manifested powerful antitumor effects in clinical trials targeting 4-1BB alone or in combination with other immune checkpoints. In this review, we will summarize the structure and expression of 4-1BB and its ligand, discuss the role of 4-1BB in the microenvironment and tumor progression, and update the development of drugs targeting 4-1BB. The purpose of the review is to furnish a comprehensive overview of the potential of 4-1BB as an immunotherapeutic target and to discuss recent advances and prospects for 4-1BB in cancer therapy.

Let’s color: An online coloring game improves subjective well-being and reduces anxiety during the COVID-19 pandemic (Preprint)

Background

COVID-19 has spread worldwide and generated tremendous stress on human beings. Unfortunately, it is often hard for distressed individuals to access mental health services under conditions of restricted movement or even lockdown.

Objective

The study first aims to develop an online digital intervention package based on a commercially released coloring game. The second aim is to test the effectiveness of difference intervention packages for players to increase subjective well-being (SWB) and reduce anxiety during the pandemic.

Methods

An evidence-based coloring intervention package was developed and uploaded to an online coloring game covering almost 1.5 million players worldwide in January 2021. Players worldwide participated to color either 4 rounds of images characterized by awe, pink, nature, and blue or 4 rounds of irrelevant images. Participants' SWB and anxiety and the perceived effectiveness of the game in reducing anxiety (subjective effectiveness [SE]) were assessed 1 week before the intervention (T1), after the participants completed pictures in each round (T2-T5), and after the intervention (T6). Independent 2-tailed t tests were conducted to examine the general intervention (GI) effect and the intervention effect of each round. Univariate analysis was used to examine whether these outcome variables were influenced by the number of rounds completed.

Results

In total, 1390 players worldwide responded and completed at least 1 assessment. Overall, the GI group showed a statistical significantly greater increase in SWB than the general control (GC) group (N=164, t162=3.59, Cohen d=0.59, 95% CI 0.36-1.24, P<.001). Compared to the control group, the best effectiveness of the intervention group was seen in the awe round, in which the increase in SWB was significant (N=171, t169=2.51, Cohen d=0.39, 95% CI 0.10-0.82, P=.01), and players who colored all 4 pictures had nearly significant improvements in SWB (N=171, F4,170=2.34, partial ŋ2=0.053, P=.06) and a significant decrease in anxiety (N=171, F4,170=3.39, partial ŋ2=0.075, P=.01).

Conclusions

These data indicate the effectiveness of online psychological interventions, such as coloring games, for mental health in the specific period. They also show the feasibility of applying existing commercial games embedded with scientific psychological interventions that can fill the gap in mental crises and services for a wider group of people during the pandemic. The results would inspire innovations to prevent the psychological problems caused by public emergencies and encourage more games, especially the most popular ones, to take more positive action for the common crises of humankind.

Cytisine Exerts an Anti-Epileptic Effect via α7nAChRs in a Rat Model of Temporal Lobe Epilepsy

Background and Purpose: Temporal lobe epilepsy (TLE) is a common chronic neurological disease that is often invulnerable to anti-epileptic drugs. Increasing data have demonstrated that acetylcholine (ACh) and cholinergic neurotransmission are involved in the pathophysiology of epilepsy. Cytisine, a full agonist of α7 nicotinic acetylcholine receptors (α7nAChRs) and a partial agonist of α4β2nAChRs, has been widely applied for smoking cessation and has shown neuroprotection in neurological diseases. However, whether cytisine plays a role in treating TLE has not yet been determined.

Experimental Approach: In this study, cytisine was injected intraperitoneally into pilocarpine-induced epileptic rats for three weeks. Alpha-bungarotoxin (α-bgt), a specific α7nAChR antagonist, was used to evaluate the mechanism of action of cytisine. Rats were assayed for the occurrence of seizures and cognitive function by video surveillance and Morris water maze. Hippocampal injuries and synaptic structure were assessed by Nissl staining and Golgi staining. Furthermore, levels of glutamate, γ-aminobutyric acid (GABA), ACh, and α7nAChRs were measured.

Results: Cytisine significantly reduced seizures and hippocampal damage while improving cognition and inhibiting synaptic remodeling in TLE rats. Additionally, cytisine decreased glutamate levels without altering GABA levels, and increased ACh levels and α7nAChR expression in the hippocampi of TLE rats. α-bgt antagonized the above-mentioned effects of cytisine treatment.

Conclusion and Implications: Taken together, these findings indicate that cytisine exerted an anti-epileptic and neuroprotective effect in TLE rats via activation of α7nAChRs, which was associated with a decrease in glutamate levels, inhibition of synaptic remodeling, and improvement of cholinergic transmission in the hippocampus. Hence, our findings not only suggest that cytisine represents a promising anti-epileptic drug, but provides evidence of α7nAChRs as a novel therapeutic target for TLE.

[Changes of the expression for genes related with senescence and the telomerase activity during cellular replicative and premature senescence in human embryonic lung fibroblasts]

Objective: To detect the alterations of telomerase activity and the expression for oxidative stress responsive genes related with senescence during cellular replicative senescence and hydrogen peroxide-induced premature senescence in human embryonic lung fibroblasts (HELFs) in vitro. Methods: The HELFs were divided into young cells (22 population doubling levels, 22PDL) , mid-aged cells (35PDL) and replicative senes-cent cells (49PDL) and premature senescent cells induced by H(2)O(2)(premature senescence, PS). The telomerase activity was detected by ELISA assay during cellular replicative and premature senescence. The mRNA level of oxidative stress responsive genes related with senescence for Foxo1, Foxo3, Pdx1, apoA-I and MMP1 was per-formed by RT-Q-PCR separately. Results: The mRNA level for Foxo1, Foxo3, apoA-I and Pdx1 was decreased separately during cellular replicative senescence compared to that in the young-stage cells with statistical signifi-cance (P<0.05). The expression of MMP1 was up-regulated 5.1-fold obviously (P<0.05). In premature senes-cence, the mRNA level was only decreased for Foxo1, Foxo3 and apoA-I, but up-regulated 2.3-fold and 6.2-fold for Pdx1 and MMP1 respcetively vs 22PDL significantly (P<0.05). The telomerase activity in young cells was not detected, and it increased in mid-aged cells and replicative senescence stages during cellular replicative se-nescence as compared to 22PDL with statistical significance (P<0.05). The telomerase activity in premature se-nescence was highly active. Conclusion: The expression for genes related with senescence has differences be-tween replicative and premature senescence and hydrogen peroxide modifies their expression levels. The telomer-ase activity has been going up with increased PDLs.

LXR agonists promote the proliferation of neural progenitor cells through MEK-ERK pathway

The liver X receptors (LXRs) are transcriptional regulators of lipid homeostasis and may be critical for neurodegeneration and neurogenesis in vivo. However, it remains largely unknown about the role of LXRs and its agonists in the in vitro proliferation of neural progenitor cells (NPCs). Here we revealed for the first time that LXRs were markedly expressed in mouse NPCs and were critical for the in vitro proliferation. LXR agonists GW3965 and LXR623 promoted the proliferation of wildtype NPCs, but not NPCs from LXR double-knockout mice. Mechanistically, phosphorylation of MEK1/2 and ERK1/2 in NPCs was enhanced upon LXR agonist treatment, while abrogation of MEK/ERK phosphorylation by the inhibitors PD98059 and U0126 impaired the proliferation of wildtype NPCs in the presence or absence of LXR agonists. Collectively, our findings suggest that LXR agonists GW3965 and LXR623 can stimulate the NPC proliferation in LXR- and MEK/ERK-dependent manner.

Valproic acid alleviates memory deficits and attenuates amyloid-β deposition in transgenic mouse model of Alzheimer's disease

In the brains of patients with Alzheimer's disease (AD) and transgenic AD mouse models, astrocytes and microglia activated by amyloid-β (Aβ) contribute to the inflammatory process that develops around injury in the brain. Valproic acid (VPA) has been shown to have anti-inflammatory function. The present study intended to explore the therapeutic effect of VPA on the neuropathology and memory deficits in APPswe/PS1ΔE9 (APP/PS1) transgenic mice. Here, we report that VPA-treated APP/PS1 mice markedly improved memory deficits and decreased Aβ deposition compared with the vehicle-treated APP/PS1 mice. Moreover, the extensive astrogliosis and microgliosis as well as the increased expression in interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the hippocampus and cortex of APP/PS1 transgenic mice were significantly reduced following administration of VPA, which attenuated neuronal degeneration. Concomitantly, VPA alleviated the levels of p65 NF-κB phosphorylation and enhanced the levels of acetyl-H3, Bcl-2, and phospho-glycogen synthase kinase (GSK)-3β that occurred in the hippocampus of APP/PS1 transgenic mice. These results demonstrate that VPA could significantly ameliorate spatial memory impairment and Aβ deposition at least in part via the inhibition of inflammation, suggesting that administration of VPA could provide a therapeutic approach for AD.

[Research the biogeochemical processes of nutrients in Minjiang Estuary]

The variations in the concentration and distribution of nutrients and influencing factors in the Minjiang Estuary with a tidal cycle were investigated based on the data obtained during field observations in May 2007. The results showed the suspended sediment, dissolved inorganic nitrogen and silicate were opposite to the change of tidal, while the water level and salinity were consistent with tidal. The buffer mechanism of phosphate was controlled by suspended sand and water. The concentrations of silicate, phosphate and inorganic nitrogen were ranged 0.63-9.00 mg/L, 0.013-0.075 mg/L, 0.33-4.24 mg/L respectively. The contents of dissolved inorganic nitrogen in water mass increased remarkably comparing 1980s because of agriculture, industry and living. The research indicated that the nitrate and silicate were conservative, but phosphate was non-conservative in the biogeochemical processes of nutrients in Minjiang Estuary. The diluted water carried abundant inorganic nitrogen, silicate nutrients to Minjiang Estuary and thus phosphate was similar between diluted water and sea water. Based on the results of nutrient ratios, it was suggested that phosphate was a limiting factor for phytoplankton growth in the Minjiang Estuary.

Breast cancer resistance protein expression and 5-fluorouracil resistance

OBJECTIVE

To filtrate breast cancer resistance protein (BCRP)-mediated resistant agents and to investigate clinical relationship between BCRP expression and drug resistance.

METHODS

MTT assay was performed to filtrate BCRP-mediated resistant agents with BCRP expression cell model and to detect chemosensitivity of breast cancer tissue specimens to these agents. A high performance liquid chromatography (HPLC) assay was established, and was used to measure the relative dose of intracellular retention resistant agents. RT-PCR and immunohistochemistry (IHC) were employed to investigate the BCRP expression in breast cancer tissue specimens.

RESULTS

MTT assay showed that the expression of BCRP increased with the increasing resistance of 5-fluorouracil (5-Fu) (P<0.05, n=3) in the cell model, while HPLC assay indicated that the intracellular retention dose of 5-Fu was significantly correlated with the expression of BCRP (r=-0.897, P<0.05, n=3). A total of 140 breast cancer tissue specimens were collected. BCRP-positive expression was detected in forty-seven specimens by both RT-PCR and IHC. As shown by MTT assay subsequently, the resistance index (RI) of 47 BCRP-positive breast cancer tissue specimens to 5-Fu was 7-12 times as high as that of adjacent normal tissue samples. BCRP expression was related to 5-Fu resistance (R2=0.8124, P<0.01).

CONCLUSION

Resistance to 5-Fu can be mediated by BCRP. Clinical chemotherapy for breast cancer patients can be optimized based on BCRP-positive expression.

Possible role of DNA polymerase beta in protecting human bronchial epithelial cells against cytotoxicity of hydroquinone

OBJECTIVE

To explore the toxicological mechanism of hydroquinone in human bronchial epithelial cells and to investigate whether DNA polymerase beta is involved in protecting cells from damage caused by hydroquinone.

METHODS

DNA polymerase beta knock-down cell line was established via RNA interference as an experimental group. Normal human bronchial epithelial cells and cells transfected with the empty vector of pEGFP-C1 were used as controls. Cells were treated with different concentrations of hydroquinone (ranged from 10 micromol/L to 120 micromol/L) for 4 hours. MTT assay and Comet assay [single-cell gel electrophoresis (SCGE)] were performed respectively to detect the toxicity of hydroquinone.

RESULTS

MTT assay showed that DNA polymerase beta knock-down cells treated with different concentrations of hydroquinone had a lower absorbance value at 490 nm than the control cells in a dose-dependant manner. Comet assay revealed that different concentrations of hydroquinone caused more severe DNA damage in DNA polymerase beta knock-down cell line than in control cells and there was no significant difference in the two control groups.

CONCLUSIONS

Hydroquinone has significant toxicity to human bronchial epithelial cells and causes DNA damage. DNA polymerase beta knock-down cell line appears more sensitive to hydroquinone than the control cells. The results suggest that DNA polymerase beta is involved in protecting cells from damage caused by hydroquinone.

Alterations of FHIT gene and P16 gene in nickel transformed human bronchial epithelial cells

OBJECTIVE

To study the alterations of FHIT gene and P16 gene in malignant transformed human bronchial epithelial cells induced by crystalline nickel sulfide using an immortal human bronchial epithelial cell line, and to explore the molecular mechanism of nickel carcinogenesis.

METHODS

16HBE cells were treated 6 times with different concentrations of NiS in vitro, and the degree of malignant transformation was determined by assaying the anchorage-independent growth and tumorigenicity. Malignant transformed cells and tumorigenic cells were examined for alterations of FHIT gene and P16 gene using RT-PCR, DNA sequencing, silver staining PCR-SSCP and Western blotting.

RESULTS

NiS-treated cells exhibited overlapping growth. Compared with that of negative control cells, soft agar colony formation efficiency of NiS-treated cells showed significant increases (P < 0.01) and dose-dependent effects. NiS-treated cells could form tumors in nude mice, and a squamous cell carcinoma was confirmed by histopathological examination. No mutation of exon 2 and exons 2-3, no abnormal expression in p16 gene and mutation of FHIT exons 5-8 and exons 1-4 or exons 5-9 were observed in transformed cells and tumorigenic cells. However, aberrant transcripts or loss of expression of the FHIT gene and Fhit protein was observed in transformed cells and tumorigenic cells. One of the aberrant transcripts in the FHIT gene was confirmed to have a deletion of exon 6, exon 7, exon 8, and an insertion of a 36 bp sequence replacing exon 6-8.

CONCLUSIONS

The FHIT gene rather than the P16 gene, plays a definite role in nickel carcinogenesis. Alterations of the FHIT gene induced by crystalline NiS may be a molecular event associated with carcinogen, chromosome fragile site instability and cell malignant transformation. FHIT may be an important target gene activated by nickel and other exotic carcinogens.

[Construction of "pEGFP-C1-pU6-dsRNA" recombinant for human DNA polymerase beta RNA interference]

OBJECTIVE

To clone the "pEGFP-C1-pU6-dsRNA" recombinant for human DNA polymerase beta RNA interference, to provide research tool for the study on the function of DNA polymerase beta in repairing of human DNA damaged by environmental chemical pollutants (ECPs).

METHODS

According to the gene sequence of polymerase beta cDNA published in Genbank, double strand RNA(dsRNA) sequence which was used in RNA interference was designed by dsRNA oligonucleotide designer and synthesized by chemical methods. DNA recombination technology was used to insert the up related dsRNA sequence into the vector of pSIREN-RetroQ, and then the "pSIREN-RetroQ-dsRNA" recombinant was obtained. After E. coli DH5alpha was transformed with the "pSIREN-RetroQ-dsRNA" recombinant and screened with ampicillin for positive clones, plasmid was extracted and digested by EcoR I and Bgl II , the fragment of"pU6-dsRNA"was purified. And then the "pU6-dsRNA"fragment was cloned into the vector of pEGFP-C1 by recombination technology, the recombinant of "pEGFP-C1-pU6-dsRNA" was obtained and identified by restriction endonuclease analysis and sequencing.

RESULTS

The "pEGFP-C1-pU6-dsRNA" recombinant lied in the predicted band, and the sequence of insert was identical to the designed target fragment.

CONCLUSION

The "pEGFP-C1-pU6-dsRNA" recombinant was successfully cloned for human DNA polymerase beta RNA interference, it was an important research tool for the further study.

[Antitransforming activity of chlorophyllin against trans-benzo(a)pyrene-trans-7,8-dihydrodiol-9,10-epoxide]

OBJECTIVE

To study the inhibitory effect of chlorophyllin (CHL) on trans-benzo(a)pyrene-trans-7,8-dihydrodiol-9,10-epoxide (BPDE) induced malignant transformation in human bronchial epithelial cell line (16HBE).

METHODS

10, 50 or 100 micro mol/L CHL were added into the media during the cells transformation induced by BPDE, and the malignant degree of transformed cells were identified by the ConA agglutination test and the assay for anchorage-independent growth and tumorigenicity.

RESULTS

After the cells were cultured for 25 times, the time of cells agglutination in groups treated with both CHL and BPDE was increased significantly; the colony formation efficiency in soft agar in groups treated with both CHL and BPDE (7.4 per thousand, 11.4 per thousand and 14.4 per thousand ) showed significant decrease (P < 0.05) in dose-dependent manner, as compared with that in group treated with BPDE alone (19.6 per thousand ). Cells treated with both CHL and BPDE or BPDE alone developed tumor in nude mice, a squamous carcinoma confirmed by histopathological examination. The volume of tumor in groups treated with both CHL and BPDE (0.43 +/- 0.13) cm(2), (0.22 +/- 0.04) cm(2) and (0.10 +/- 0.06) cm(3) was significantly smaller (P < 0.05) and dose-dependent, as compared with that in the group treated with BPDE alone (1.71 +/- 0.37) cm(3).

CONCLUSION

CHL showed significant antitransforming ability in human bronchial epithelial cell line induced by BPDE.