Inhibition of MNK pathway sensitizes nasopharyngeal carcinoma to radiotherapy.

Improving the clinical management of nasopharyngeal carcinoma (NPC) is an unmet need owing to the high incidence of treatment failure caused by radioresistance. In our study, we observed increased phosphorylation of translation initiation factor 4E (eIF4E), regulated by MAP kinase-interacting kinase (MNK), in NPC cells following irradiation treatment. Using siRNA to deplete MNK, we found that radiation-induced eIF4E phosphorylation was eliminated, NPC cell sensitivity to radiation was enhanced, and radioresistant NPC cell viability was reduced. Furthermore, we tested three pharmacological MNK inhibitors (eFT508, CGP57380, and cercosporamide) and found that they were effective against radioresistant NPC cells and synergized with irradiation. In-vivo experiments confirmed that eFT508, at a tolerable dose, inhibited the growth of radioresistant NPC and synergized with radiation in a radiosensitive NPC xenograft model. Our research highlights the activation of MNK-mediated survival mechanisms in NPC in response to radiotherapy and the potential of combining radiation with MNK inhibitors as a sensitizing strategy. Notably, eFT508 is currently being investigated in clinical trials for cancer treatment, and our findings may prompt the initiation of clinical trials using eFT508 in radioresistant NPC patients.

All-or-none disconnection of pyramidal inputs onto parvalbumin-positive interneurons gates ocular dominance plasticity.

Disinhibition is an obligatory initial step in the remodeling of cortical circuits by sensory experience. Our investigation on disinhibitory mechanisms in the classical model of ocular dominance plasticity uncovered an unexpected form of experience-dependent circuit plasticity. In the layer 2/3 of mouse visual cortex, monocular deprivation triggers a complete, "all-or-none," elimination of connections from pyramidal cells onto nearby parvalbumin-positive interneurons (Pyr→PV). This binary form of circuit plasticity is unique, as it is transient, local, and discrete. It lasts only 1 d, and it does not manifest as widespread changes in synaptic strength; rather, only about half of local connections are lost, and the remaining ones are not affected in strength. Mechanistically, the deprivation-induced loss of Pyr→PV is contingent on a reduction of the protein neuropentraxin2. Functionally, the loss of Pyr→PV is absolutely necessary for ocular dominance plasticity, a canonical model of deprivation-induced model of cortical remodeling. We surmise, therefore, that this all-or-none loss of local Pyr→PV circuitry gates experience-dependent cortical plasticity.

Matrix metalloproteinase-21 promotes metastasis via increasing the recruitment and M2 polarization of macrophages in HCC.

MMP-21 is a newly identified member of the matrix metalloproteinase family and has been reported to regulate both embryonic development and tumor progression. However, the roles of MMP-21 in hemofiltrate C-C chemokine (HCC) remain largely unclear. In this study, we used western blot, qPCR and immunohistochemistry (IHC) to determine the upregulation of MMP-21 in HCC tissues, and showed that the increase in MMP-21 was associated with vascular invasion and poor prognosis. Although changing levels of MMP-21 in HCC cell lines had no significant effect on cell migration or invasion abilities in in vitro transwell tests, both IHC analysis and in vivo mouse models proved that upregulated MMP-21 promoted metastasis. Functional enrichments of MMP-21 using The Cancer Genome Atlas (TCGA) data suggested that MMP-21 might regulate metastasis via macrophages. Further experiments proved that MMP-21 enhanced macrophage recruitment by increasing CCL-14 levels and promoted M2-type polarization of macrophage by elevating the expression of CSF-1 and FGF-1. Taken together, this study revealed that MMP-21 controlled the tumor microenvironment remodeling and functional regulation of macrophages to regulate HCC metastasis.

Comprehensive Analysis of Genomic and Expression Data Identified Potential Markers for Predicting Prognosis and Immune Response in CRC.

Colorectal cancer (CRC) is the most prevalent type of malignant tumor of the gastrointestinal tract. In the current study, we characterized the landscape of genomic alterations in CRC patients. Based on the results of whole-exome sequencing (WES), we identified 31 significantly mutated genes. Among them, several genes including TP53, KRAS, APC, PI3KCA, and BRAF were reported as significantly mutated genes in previous studies. In the current study, the most frequently mutated gene was TP53, which encodes tumor suppressor p53, affecting approximately 60% of CRC patients. In addition, we performed the expression profiles of significantly mutated genes between the normal group and tumor groups and identified 20 differentially expressed genes (DEGs); among them, CSMD3, DCHS2, LRP2, RYR2, and ZFHX4 were significantly negatively correlated with PFS. Moreover, consensus clustering analysis for CRC based on the expression of significantly somatic mutated genes was performed. In total, three subtypes of CRC were identified in CRC, including cluster1 (n = 453), cluster2 (n = 158), and cluster 3 (n = 9), based on expression level of significantly somatic mutated genes. Clinicopathological features analysis showed subtype C1 had the longest progression-free survival (PFS) with median time of 8.2 years, while subtypes C2 and C3 had 4.1 and 2.7 years of PFS, respectively. Moreover, we found three subtypes related to tumor infiltration depth, lymph node metastasis, and distant metastasis. Immune infiltration analysis showed the tumor infiltration levels of B cell native, T cell CD8+, T cell CD4+ memory activated, T cell gamma delta, NK cell resting, macrophage M0, macrophage M2, myeloid dendritic cell activated, mast cell activated, and mast cell resting significantly changed among the three groups, demonstrating the three subgroups classified by 22 somatically significantly mutated genes had a high capacity to differentiate patients with different immune statuses, which is helpful for the prediction of immunotherapy response of CRC patients. Our findings could provide novel potential predictive indicators for CRC prognosis and therapy targets for CRC immunotherapy.

Inhibition of mTOR by temsirolimus overcomes radio-resistance in nasopharyngeal carcinoma.

Radio-resistance is a leading cause of nasopharyngeal carcinoma (NPC) treatment failure and identification of sensitising therapeutic targets is an unmet need to enhance clinical management. Given that the mammalian target of rapamycin (mTOR) signalling confers resistance to cancer therapy, we investigated whether mTOR contributes to radio-resistance in NPC and pharmacological inhibition of mTOR can overcome radio-resistance. We found that mTOR mRNA and protein levels, and phosphorylation of its downstream effector were increased in radio-resistant NPC compared with parental cells. mTOR inhibitor temsirolimus inhibits proliferation and induces apoptosis in a panel of NPC cell lines. Importantly, temsirolimus acts synergistically with radiation and is effective against radio-resistant cells. Using radio-resistant xenograft mouse model, we validated the efficacy of temsirolimus in preventing tumour formation and inhibiting tumour growth. Temsirolimus overcome radio-resistance in NPC via inhibiting mTOR signalling. Our work provides the pre-clinical evidence that the combination of radiation and mTOR inhibitor may be a therapeutic strategy in NPC. Our findings might accelerate the initiation of clinical trials on radio-resistant NPC patients using temsirolimus.

Parvalbumin subtypes of cerebellar Purkinje cells contribute to differential intrinsic firing properties.

Purkinje cells (PCs) are central to cerebellar information coding and appreciation for the diversity of their firing patterns and molecular profiles is growing. Heterogeneous subpopulations of PCs have been identified that display differences in intrinsic firing properties without clear mechanistic insight into what underlies the divergence in firing parameters. Although long used as a general PC marker, we report that the calcium binding protein parvalbumin labels a subpopulation of PCs, based on high and low expression, with a conserved distribution pattern across the animals examined. We trained a convolutional neural network to recognize the parvalbumin subtypes and create maps of whole cerebellar distribution and find that PCs within these areas have differences in spontaneous firing that can be modified by altering calcium buffer content. These subtypes also show differential responses to potassium and calcium channel blockade, suggesting a mechanistic role for variability in PC intrinsic firing through differences in ion channel composition. It is proposed that ion channels drive the diversity in PC intrinsic firing phenotype and parvalbumin calcium buffering provides capacity for the highest firing rates observed. These findings open new avenues for detailed classification of PC subtypes.

A Review of the Recent Developments in the Bioproduction of Polylactic Acid and Its Precursors Optically Pure Lactic Acids.

Lactic acid (LA) is an important organic acid with broad industrial applications. Considered as an environmentally friendly alternative to petroleum-based plastic with a wide range of applications, polylactic acid has generated a great deal of interest and therefore the demand for optically pure l- or d-lactic acid has increased accordingly. Microbial fermentation is the industrial route for LA production. LA bacteria and certain genetic engineering bacteria are widely used for LA production. Although some fungi, such as Saccharomyces cerevisiae, are not natural LA producers, they have recently received increased attention for LA production because of their acid tolerance. The main challenge for LA bioproduction is the high cost of substrates. The development of LA production from cost-effective biomasses is a potential solution to reduce the cost of LA production. This review examined and discussed recent progress in optically pure l-lactic acid and optically pure d-lactic acid fermentation. The utilization of inexpensive substrates is also focused on. Additionally, for PLA production, a complete biological process by one-step fermentation from renewable resources is also currently being developed by metabolically engineered bacteria. We also summarize the strategies and procedures for metabolically engineering microorganisms producing PLA. In addition, there exists some challenges to efficiently produce PLA, therefore strategies to overcome these challenges through metabolic engineering combined with enzyme engineering are also discussed.

Tomosyn regulates the small RhoA GTPase to control the dendritic stability of neurons and the surface expression of AMPA receptors.

Tomosyn, a protein encoded by syntaxin-1-binding protein 5 (STXBP5) gene, has a well-established presynaptic role in the inhibition of neurotransmitter release and the reduction of synaptic transmission by its canonical interaction with the soluble N-ethylmaleimide-sensitive factor attachment protein receptor machinery. However, the postsynaptic role of tomosyn in dendritic arborization, spine stability, and trafficking of ionotropic glutamate receptors remains to be elucidated. We used short hairpin RNA to knock down tomosyn in mouse primary neurons to evaluate the postsynaptic cellular function and molecular signaling regulated by tomosyn. Knockdown of tomosyn led to an increase of RhoA GTPase activity accompanied by compromised dendritic arborization, loss of dendritic spines, decreased surface expression of AMPA receptors, and reduced miniature excitatory postsynaptic current frequency. Inhibiting RhoA signaling was sufficient to rescue the abnormal dendritic morphology and the surface expression of AMPA receptors. The function of tomosyn regulating RhoA is mediated through the N-terminal WD40 motif, where two variants each carrying a single nucleotide mutation in this region were found in individuals with autism spectrum disorder (ASD). We demonstrated that these variants displayed loss-of-function phenotypes. Unlike the wild-type tomosyn, these two variants failed to restore the reduced dendritic complexity, spine density, as well as decreased surface expression of AMPA receptors in tomosyn knockdown neurons. This study uncovers a novel role of tomosyn in maintaining neuronal function by inhibiting RhoA activity. Further analysis of tomosyn variants also provides a potential mechanism for explaining cellular pathology in ASD.

MDR1 gene polymorphism correlated with pathological characteristics and prognosis in patients with primary hepatocellular carcinoma receiving interventional therapy.

The aim of this study was to explore the relationship of multidrug resistance gene 1 (MDR1) C1236T and C3435T single nucleotides polymorphisms (SNPs) with hepatocellular carcinoma (HCC) pathological features and prognosis. A total of 143 patients with HCC were treated with transcatheter arterial chemoembolization. Moreover, 251 controls were included in the study. C1236T and C3435T single nucleotide polymorphisms (SNPs) were detected by PCR-RFLP. Association of C1236T and C3435T SNPs with HCC was analyzed subsequently. There was no significant difference in genotypes distribution between HCC group and control group (P>0.05), indicating comparability. Among patients with portal vein tumor thrombus, the CC+CT genotype of C1236T locus was significantly higher than that of TT genotype (P=0.031). The median progression-free survival after interventional therapy for patients with C3435T genotype T (TC+TT) and C genotype (CC) was 36 and 18 months, respectively. CC and TC+TT genotype patients with C1236T loci showed statistically significant differences in tumor size stratification (χ=4.006, P=0.045). When tumor diameter was less than 5 cm, 5-10 cm, and more than 10 cm, the mean survival time of C and T genotypes was decreased gradually. The logistic regression model suggested that lesion size, blood volume value, and permeability surface value were influential factors for response to chemoradiotherapy (all P<0.05). Univariate analysis showed that postoperative chemotherapy, portal vein tumor thrombus, and capsular invasion were correlated with overall survival in patients with HCC. Cox proportional hazard model showed that postoperative chemotherapy, capsule invasion, and portal vein tumor thrombus were independent factors of overall survival after interventional therapy in patients with HCC (all P<0.05). C1236T genotype may predict changes in pathological features of patients with HCC to a certain extent, and C3435T SNP can be used as one of the prognostic factors of HCC. Postoperative chemotherapy and portal vein tumor thrombus are independent factors of overall survival in patients with HCC.

Effects of secreted frizzled-related protein 1 on proliferation, migration, invasion, and apoptosis of colorectal cancer cells.

BACKGROUND: Secreted frizzled-related protein 1 (SFRP1) is a member of the SFRPs family that modulates the Wnt signal transduction pathway. Recent studies have showed down-regulation of SFRP1 expression in colorectal cancer (CRC). We aimed to evaluate the effect of SFRP1 on the proliferation, migration, invasion and apoptosis of CRC cells in vitro. MATERIALS AND METHODS: We used real-time fluorescence quantification (RT-PCR) and Western blotting to detect SFRP1 expression in CRC, pericarcinomatous tissues and CRC cell lines. We assessed the influence of overexpression and knockdown of SFRP1 on CRC cell proliferation, migration, invasion, and apoptosis, Western blotting was used to evaluate protein levels of Wnt, ß-catenin, and apoptosis-related proteins. RESULTS: The expression of SFRP1 was significantly decreased in CRC tissues. Among the six CRC cell lines (sw-480, sw1116, caco-2, ht-29, colo-205, and hct-116), RT-PCR revealed that sw1116 cells had the lowest expression of SFRP1, while caco-2 cells had the highest SFRP1 expression. SFRP1 overexpression in sw1116 cells significantly suppressed cell proliferation while SFRP1 knockdown in caco-2 cells significantly increase the cell proliferation. In addition, overexpression of SFRP1 in sw1116 cells remarkedly suppressed cell migration and invasion, whereas knockdown of SFRP1 in caco-2 cells resulted in significant enhancement of migration and invasion. Furthermore, SFRP1 overexpression in sw1116 cells promoted cell apoptosis. Western blotting showed that SFRP1 overexpression significantly decreased the protein levels of Wnt, ß-catenin and apoptosis-related proteins, including MMP2, MMP9, Twist, CDK1, TGF, and Bcl2. CONCLUSION: Our results demonstrate that SFRP1 suppresses cell proliferation, migration and invasion, and promotes apoptosis in CRC cells.

Brief Dark Exposure Reduces Tonic Inhibition in Visual Cortex.

Tonic inhibition mediated by extrasynaptic GABA(A) receptors (GABARs) sensing ambient levels of GABA can profoundly alter the membrane input resistance to affect cellular excitability. Therefore, regulation of tonic inhibition is an attractive mechanism to control the levels of cortical firing. In cortical pyramidal cells, tonic inhibition is regulated by age and several neurotransmitters and is affected by stroke and epilepsy. However, the possible role of sensory experience has not been examined. Here, we report that a brief 2-day exposure to dark reduces by 1/3 the inhibitory tonic conductance recorded in layer II/III pyramidal cells of the mouse juvenile (postnatal day 12-27) visual cortex. In these cells, tonic inhibition is carried primarily by GABARs containing the δ subunit. Consistently, the dark exposure reduction in conductance was associated with a reduction in δ subunit levels, which were not affected in control frontal cortex. We propose that a deprivation-induced reduction in tonic inhibition might serve a homeostatic function by increasing the firing levels of cells in deprived cortical circuits.

Reduced production of ethyl carbamate for wine fermentation by deleting CAR1 in Saccharomyces cerevisiae.

Ethyl carbamate (EC), a pluripotent carcinogen, is mainly formed by a spontaneous chemical reaction of ethanol with urea in wine. The arginine, one of the major amino acids in grape musts, is metabolized by arginase (encoded by CAR1) to ornithine and urea. To reduce the production of urea and EC, an arginase-deficient recombinant strain YZ22 (Δcarl/Δcarl) was constructed from a diploid wine yeast, WY1, by successive deletion of two CAR1 alleles to block the pathway of urea production. The RT-qPCR results indicated that the YZ22 almost did not express CAR1 gene and the specific arginase activity of strain YZ22 was 12.64 times lower than that of parent strain WY1. The fermentation results showed that the content of urea and EC in wine decreased by 77.89 and 73.78 %, respectively. Furthermore, EC was forming in a much lower speed with the lower urea during wine storage. Moreover, the two CAR1 allele deletion strain YZ22 was substantially equivalent to parental strain in terms of growth and fermentation characteristics. Our research also suggested that EC in wine originates mainly from urea that is produced by the arginine.

Associative Hebbian synaptic plasticity in primate visual cortex.

In primates, the functional connectivity of adult primary visual cortex is susceptible to be modified by sensory training during perceptual learning. It is widely held that this type of neural plasticity might involve mechanisms like long-term potentiation (LTP) and long-term depression (LTD). NMDAR-dependent forms of LTP and LTD are particularly attractive because in rodents they can be induced in a Hebbian manner by near coincidental presynaptic and postsynaptic firing, in a paradigm termed spike timing-dependent plasticity (STDP). These fundamental properties of LTP and LTD, Hebbian induction and NMDAR dependence, have not been examined in primate cortex. Here we demonstrate these properties in the primary visual cortex of the rhesus macaque (Macaca mulatta), and also show that, like in rodents, STDP is gated by neuromodulators. These findings indicate that the cellular principles governing cortical plasticity are conserved across mammalian species, further validating the use of rodents as a model system.

Adrenergic gating of Hebbian spike-timing-dependent plasticity in cortical interneurons.

In pyramidal cells, the induction of spike-dependent plasticity (STDP) follows a simple Hebbian rule in which the order of presynaptic and postsynaptic firing dictates the induction of LTP or LTD. In contrast, cortical fast spiking (FS) interneurons, which control the rate and timing of pyramidal cell firing, reportedly express timing-dependent LTD, but not timing-dependent LTP. Because a mismatch in STDP rules could impact the maintenance of the excitation/inhibition balance, we examined the neuromodulation of STDP in FS cells of mouse visual cortex. We found that stimulation of adrenergic receptors enables the induction of Hebbian bidirectional STDP in FS cells in a manner consistent with a pull-push mechanism previously characterized in pyramidal cells. However, in pyramidal cells, STDP induction depends on NMDA receptors, whereas in FS cells it depends on mGluR5 receptors. We propose that neuromodulators control the polarity of STDP in different synapses in the same manner, and independently of the induction mechanism, by acting downstream in the plasticity cascade. By doing so, neuromodulators may allow coordinated plastic changes in FS and pyramidal cells.

Self-endowed magnetic photocatalysts derived from iron-rich sludge and its recycling in photocatalytic process for tetracycline degradation.

The disposal of iron-rich sludge by landfill or incineration poses environmental risks and wastes resources. The utilization of iron-rich sludge for magnetic material preparation offers a sustainable and resource-efficient solution for its disposal. Herein, self-endowed magnetic photocatalysts were initially prepared by pyrolysis using iron-rich sludge without any additives. The photocatalysts performance were evaluated for tetracycline degradation, with the highest degradation rate of 95.3 % at a concentration of 10 mg·L-1 (pH = 7) within 5 h being achieved for the photocatalyst prepared at 800 °C. The reactive radical species in the photocatalysis process were confirmed to be •OH and O2•- activated by ferrous oxygen species under light irradiation. Furthermore, quinone-like structures induced bound persistent free radicals, which emerged as the predominant factors influencing 1O2 formation. The employed photocatalyst can be efficiently separated and recovered owing to its magnetism. This work presents an economic solution for antibiotic removal using waste iron-rich sludge.

Dark exposure extends the integration window for spike-timing-dependent plasticity.

Metaplasticity, the adaptive changes of long-term potentiation (LTP) and long-term depression (LTD) in response to fluctuations in neural activity is well documented in visual cortex, where dark rearing shifts the frequency threshold for the induction of LTP and LTD. Here we studied metaplasticity affecting spike-timing-dependent plasticity, in which the polarity of plasticity is determined not by the stimulation frequency, but by the temporal relationship between near-coincidental presynaptic and postsynaptic firing. We found that in mouse visual cortex the same regime of deprivation that restricts the frequency range for inducing rate-dependent LTD extends the integration window for inducing timing-dependent LTD, enabling LTD induction with random presynaptic and postsynaptic firing. Notably, the underlying mechanism for the changes in both rate-dependent and time-dependent LTD appears to be an increase of NR2b-containing NMDAR at the synapse. Thus, the rules of metaplasticity might manifest in opposite directions, depending on the plasticity-induction paradigms.

Development and Validation of a Nomogram to Predict Overall Survival in Stage I-III Colorectal Cancer Patients after Radical Resection with Normal Preoperative Serum Carcinoembryonic Antigen.

We aimed to develop a clinical predictive model for predicting the overall survival (OS) in stage I-III CRC patients after radical resection with normal preoperative CEA. This study included 1082 consecutive patients. They were further divided into a training set (70%) and a validation set (30%). The selection of variables for the model was informed by the Akaike information criterion. After that, the clinical predictive model was constructed, evaluated, and validated. The net reclassification index (NRI) and integrated discrimination improvement (IDI) were employed to compare the models. Age, histologic type, pT stage, pN stage, carbohydrate antigen 242 (CA242), and carbohydrate antigen 125 (CA125) were selected to establish a clinical prediction model for OS. The concordance index (C-index) (0.748 for the training set and 0.702 for the validation set) indicated that the nomogram had good discrimination ability. The decision curve analysis highlighted that the model has superior efficiency in clinical decision-making. NRI and IDI showed that the established nomogram markedly outperformed the TNM stage. The new clinical prediction model was notably superior to the AJCC 8th TNM stage, and it can be used to accurately assess the OS of stage I-III CRC patients undergoing radical resection with normal preoperative CEA.

Clinical Characteristics and Postoperative Complications in Patients Undergoing Colorectal Cancer Surgery with Perioperative COVID-19 Infection.

With the emergence of novel variants, there have been widespread COVID-19 infections in the Chinese mainland recently. Compared to ancestral COVID-19 variants, Omicron variants become more infectious, but less virulent. Previous studies have recommended postponing non-emergency surgery for at least 4-8 weeks after COVID-19 infection. However, delayed surgery has been shown to be associated with tumor progression and worse overall survival for cancer patients. Here, we examined surgery risk and optimal timing for colorectal cancer patients with perioperative COVID-19 infection. A total of 211 patients who underwent colorectal cancer surgery from 1 October 2022 to 20 January 2023 at Xinhua Hospital were included. In addition, COVID-19-infected patients were further categorized into three groups based on infected time (early post-COVID-19 group, late post-COVID-19 group and postoperative COVID-19 group). The complication rate in patients with COVID-19 infection was 26.3%, which was significantly higher than in control patients (8.4%). The most common complications in COVID-19-infected patients were pneumonia, ileus and sepsis. Patients who underwent surgery close to the time of infection had increased surgery risks, whereas surgery performed over 1 week after recovery from COVID-19 did not increase the risk of postoperative complications. In conclusion, surgery performed during or near the time of COVID-19 infection is associated with an increased risk of developing postoperative complications. We recommend that the safe period for patients with recent COVID-19 infection in colorectal cancer surgery be at least 1 week after recovery from COVID-19.

Refractory microsatellite stable metastatic colorectal cancer with ERBB2/ERBB3 mutation may be preferred population for regorafenib plus PD-1 inhibitor therapy: a real-world study.

Background: Microsatellite stable (MSS) colorectal cancer (CRC) has been referred to as the "cold tumor" because of almost no response to anti-programmed death-1 (PD-1) antibody. A recent REGONIVO trial showed that regorafenib plus nivolumab had an encouraging efficacy in MSS metastatic CRC (mCRC). However, only a small subset of patients may benefit from the combination therapy. We aim to evaluate the efficacy and safety data of immune checkpoint inhibitors combined with regorafenib in refractory MSS mCRC and to discover biomarkers that can effectively stratify the beneficial patient population. Methods: We retrospectively analyzed patients with MSS mCRC who received regorafenib combined with anti-PD-1 antibody therapy. The objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and status of gene mutation were reviewed and evaluated. Results: Twenty-one patients received combination treatment. At a median treatment duration of 4 months, one patient achieved complete response, three patients achieved partial response, and two patients achieved stable disease as the best response. The ORR and DCR were 19% and 28.5% in the overall population, respectively. The median PFS was 4 months, and the median OS was 25 months. Only erbb2 receptor tyrosine kinase 2/erbb3 receptor tyrosine kinase 3 (ERBB2/ERBB3) mutation status was confirmed to be a potential predictive factor for effective treatment. In patients with ERBB2/ERBB3 mutation, ORR, DCR, and PFS exhibited significant improvements in comparison with that in wild-type patients. Grade 3 or higher treatment-related adverse events occurred in three patients (14.3%). Conclusions: Regorafenib in combination with PD-1 inhibitor provides a feasible treatment regimen for refractory MSS mCRC with tolerated toxicity. Patients with ERBB2/ERBB3 mutation may be the preferred population for this combination regimen.

Targeted Knockdown of Macrophage Migration Inhibitory Factor Enhances UVB Irradiation-Induced Apoptosis Via Increasing ROS Generation in Oral Squamous Cell Carcinoma.

Objectives: We investigated the effects of macrophage migration inhibitory factor (MIF) knockdown or overexpression combined with ultraviolet radiation B (UVB) irradiation on cell proliferation and apoptosis of oral squamous cell carcinoma (OSCC). Methods: MIF expression in OSCC and adjacent tissues was detected by immunohistochemistry. MIF expression in human immortalized oral epithelial cells (HIOEC) and OSCC cells was detected by western blotting. MIF was knocked down or overexpressed in OSCC cell lines (SCC-25 and CAL-27). OSCC cells were set up into control (CON), MIF overexpression/knockdown (oeMIF/shMIF), CON + UVB, and oeMIF + UVB/shMIF + UVB groups based on their exposure to UVB irradiation. Cell line proliferation was studied using a cell counting kit-8 (CCK-8) and colony formation assays. Flow cytometry was applied for determination of apoptosis, cell cycle, reactive oxygen species (ROS) abundance, and mitochondrial membrane potential. Apoptosis-related proteins were assayed by western blotting. Results: The expression of MIF was significantly higher in OSCC tissues and cell lines than in adjacent tissues and HIOEC. MIF knockdown accompanied by UVB irradiation significantly hampered cell viability and proliferation compared to MIF knockdown or UVB irradiation alone. Western blotting and flow cytometry showed that MIF knockdown combined with UVB irradiation not only induced apoptosis via the mitochondrial pathway but also mediated the cell cycle. Flow cytometry showed that ROS and mitochondrial membrane potential depolarization were increased in the combination treatment groups compared with the mono-treatment groups. Additionally, the ROS scavenger N-acetylcysteine significantly attenuated MIF knockdown combined with UVB irradiation-induced apoptosis and reversed MIF knockdown combined with UVB irradiation-induced MAPK activation. Conclusion: MIF knockdown combined with UVB irradiation significantly inhibited the proliferation of OSCC cells. MIF was involved in UVB-induced ROS generation and enhanced UVB irradiation-induced mitochondria-dependent apoptosis of OSCC cells by activating the MAPK pathway. This suggests that MIF-targeted therapy combined with UVB irradiation may be a novel approach for treating OSCC.