Efficacy and Safety of Programmed Death 1/Programmed Death-Ligand 1 Plus Cytotoxic T-Lymphocyte-Associated Antigen 4 Inhibitors for Advanced or Metastatic Non-Small Cell Lung Cancer: A Meta-analysis Based on Randomized Controlled Trials.

BACKGROUND: This meta-analysis aims to investigate the efficacy and safety of programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) combined with cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitors for patients with advanced or metastatic non-small cell lung cancer (NSCLC). METHODS: Authors conducted a comprehensive search of PubMed, Embase, Cochrane Library, Web of Science, Scopus, and Medline for randomized controlled trials comparing the prognosis and safety of PD-1/PD-L1 plus CTLA-4 inhibitors with other therapies for advanced or metastatic NSCLC. Hazard ratios (HRs) and 95% confidence intervals (CIs) were used as effect sizes. The primary outcomes of this study were overall survival (OS) and progression-free survival. RESULTS: A total of 4943 patients diagnosed with stage III/IV advanced or metastatic NSCLC were included in the analysis of the 6 randomized controlled trials. The results showed that patients receiving dual immunotherapy with PD-1/PD-L1 plus CTLA-4 inhibitors had a longer survival time compared with the control group (HR = 0.88, P = 0.044). However, no statistically significant difference was observed in progression-free survival (HR = 0.95, P = 0.579). Subgroup analysis revealed better OS in the interventional group for patients aged >65 years (HR = 0.88, P = 0.076), smokers (HR = 0.81, P = 0.036), and those with a tumor mutational burden (TMB) ≥20 mut/Mb (HR = 0.66, P < 0.001). Conversely, the control group demonstrated superior OS in patients with TMB <20 mut/Mb (HR = 1.14, P = 0.048). In addition, the statistical results indicated a lower incidence rate of any-grade anemia in the dual immunotherapy group compared with the control group (RR = 0.32, P = 0.04). CONCLUSIONS: This meta-analysis demonstrates the effectiveness and safety of dual immunotherapy with PD-1/PD-L1 plus CTLA-4 inhibitors for treating advanced or metastatic NSCLC. Its efficacy is influenced by certain clinical and pathological factors, such as age, smoking status, and TMB.

The relationship between dairy products intake and breast cancer incidence: a meta-analysis of observational studies.

BACKGROUND: The effect of dairy products intake on breast cancer (BC) is highly controversial. This study aims to investigate the relationship between dairy intake and BC incidence. METHODS: A search was carried out in PubMed, EBSCO, Web of Science, and Cochrane Library databases before January 2021. The primary objective was the risk of BC and intake of dairy products were exposure variables. RESULTS: The meta-analysis comprised 36 articles with 1,019,232 participants. Total dairy products have a protective effect on female population (hazard ratio (HR) =0.95, 95% confidence interval (CI) =0.91-0.99, p = 0.019), especially for estrogen receptor-positive (ER+) (HR = 0.79, p = 0.002) and progesterone receptor-positive (PR+) BC (HR = 0.75, p = 0.027). For ER+/PR+ BC, there is a trend of protection, but it has not reached statistical significance (HR = 0.92, p = 0.075). Fermented dairy products can reduce BC risk in postmenopausal population (HR = 0.96, 95%CI = 0.93-0.99, p = 0.021), but have no protective effect on premenopausal population (HR = 0.98, 95%CI = 0.94-1.03, p = 0.52). Non-fermented dairy products have no significant effect on BC occurrence (p > 0.05). High-fat dairy products are harmful to women, without statistical difference (HR = 1.06, 95%CI = 1.00-1.13, p = 0.066). On the contrary, low-fat dairy products can protect the premenopausal population (HR = 0.94, 95%CI = 0.89-1.00, p = 0.048). CONCLUSION: The intake of dairy products can overall reduce BC risk in the female population, but different dairy products have varying effects on different BC subtypes and menopausal status.

The cytokine FAM3B/PANDER is an FGFR ligand that promotes posterior development in Xenopus.

Fibroblast growth factor (FGF)/extracellular signal-regulated kinase (ERK) signaling plays a crucial role in anterior-posterior (A-P) axial patterning of vertebrate embryos by promoting posterior development. In our screens for novel developmental regulators in Xenopus embryos, we identified Fam3b as a secreted factor regulated in ectodermal explants. Family with sequence similarity 3 member B (FAM3B)/PANDER (pancreatic-derived factor) is a cytokine involved in glucose metabolism, type 2 diabetes, and cancer in mammals. However, the molecular mechanism of FAM3B action in these processes remains poorly understood, largely because its receptor is still unidentified. Here we uncover an unexpected role of FAM3B acting as a FGF receptor (FGFR) ligand in Xenopus embryos. fam3b messenger RNA (mRNA) is initially expressed maternally and uniformly in the early Xenopus embryo and then in the epidermis at neurula stages. Overexpression of Xenopus fam3b mRNA inhibited cephalic structures and induced ectopic tail-like structures. Recombinant human FAM3B protein was purified readily from transfected tissue culture cells and, when injected into the blastocoele cavity, also caused outgrowth of tail-like structures at the expense of anterior structures, indicating FGF-like activity. Depletion of fam3b by specific antisense morpholino oligonucleotides in Xenopus resulted in macrocephaly in tailbud tadpoles, rescuable by FAM3B protein. Mechanistically, FAM3B protein bound to FGFR and activated the downstream ERK signaling in an FGFR-dependent manner. In Xenopus embryos, FGFR activity was required epistatically downstream of Fam3b to mediate its promotion of posterior cell fates. Our findings define a FAM3B/FGFR/ERK-signaling pathway that is required for axial patterning in Xenopus embryos and may provide molecular insights into FAM3B-associated human diseases.

Phase separation of Axin organizes the ß-catenin destruction complex.

In Wnt/ß-catenin signaling, the ß-catenin protein level is deliberately controlled by the assembly of the multiprotein ß-catenin destruction complex composed of Axin, adenomatous polyposis coli (APC), glycogen synthase kinase 3ß (GSK3ß), casein kinase 1α (CK1α), and others. Here we provide compelling evidence that formation of the destruction complex is driven by protein liquid-liquid phase separation (LLPS) of Axin. An intrinsically disordered region in Axin plays an important role in driving its LLPS. Phase-separated Axin provides a scaffold for recruiting GSK3ß, CK1α, and ß-catenin. APC also undergoes LLPS in vitro and enhances the size and dynamics of Axin phase droplets. The LLPS-driven assembly of the destruction complex facilitates ß-catenin phosphorylation by GSK3ß and is critical for the regulation of ß-catenin protein stability and thus Wnt/ß-catenin signaling.

Compound C induces protective autophagy in human cholangiocarcinoma cells via Akt/mTOR-independent pathway.

Compound C, a well-known inhibitor of AMP-activated protein kinase (AMPK), has been reported to exert antitumor activities in some types of cells. Whether compound C can exert antitumor effects in human cholangiocarcinoma (CCA) remains unknown. Here, we demonstrated that compound C is a potent inducer of cell death and autophagy in human CCA cells. Autophagy inhibitors increased the cytotoxicity of compound C towards human CCA cells, as confirmed by increased LDH release, and PARP cleavage. It is notable that compound C treatment increased phosphorylated Akt, sustained high levels of phosphorylated p70S6K, and decreased mTOR regulated p-ULK1 (ser757). Based on the data that blocking PI3K/Akt or mTOR had no apparent influence on autophagic response, we suggest that compound C induces autophagy independent of Akt/mTOR signaling in human CCA cells. Further study demonstrated that compound C inhibited the phosphorylation of JNK and its target c-Jun. Blocking JNK by SP600125 or siRNA suppressed autophagy induction upon compound C treatment. Moreover, compound C induced p38 MAPK activation, and its inhibition promoted autophagy induction via JNK activation. In addition, compound C induced p53 expression, and its inhibition attenuated compound C-induced autophagic response. Thus, compound C triggers autophagy, at least in part, via the JNK and p53 pathways in human CCA cells. In conclusion, suppresses autophagy could increase compound C sensitivity in human CCA.

c­Myc promotes cholangiocarcinoma cells to overcome contact inhibition via the mTOR pathway.

The loss of contact inhibition is a hallmark of a wide range of human cancer cells. Yet, the precise mechanism behind this process is not fully understood. c­Myc plays a pivotal role in carcinogenesis, but its involvement in regulating contact inhibition has not been explored to date. Here, we report that c­Myc plays an important role in abrogating contact inhibition in human cholangiocarcinoma (CCA) cells. Our data show that the protein level of c­Myc obviously decreased in contact-inhibited normal biliary epithelial cells. However, CCA cells sustain high protein levels of c­Myc and keep strong proliferation ability in confluent conditions. Importantly, the suppression of c­Myc by inhibitor or siRNA induced G0/G1 phase cell cycle arrest in confluent CCA cells. We demonstrate that the inhibition of c­Myc suppressed the activity of mammalian target of rapamycin (mTOR) in confluent CCA cells, and mTOR inhibition induced G0/G1 phase cell cycle arrest in confluent CCA cells. In confluent CCA cells, the activity of Merlin is downregulated, and Yes-associated protein (YAP) sustains high levels of activity. Furthermore, YAP inhibition not only induced G0/G1 phase cell cycle arrest, but also decreased c­Myc expression in confluent CCA cells. These results indicate that Merlin/YAP/c­Myc/mTOR signaling axis promotes human CCA cell proliferation by overriding contact inhibition. We propose that overriding c­Myc­mediated contact inhibition is implicated in the development of CCA.

Ascl1 represses the mesendoderm induction in Xenopus.

Ascl1 is a multi-functional regulator of neural development in invertebrates and vertebrates. Ectopic expression of Ascl1 can generate functional neurons from non-neural somatic cells. The abnormal expression of ASCL1 has been reported in several types of carcinomas. We have previously identified Ascl1 as a crucial maternal regulator of the germ layer pattern formation in Xenopus Functional studies have indicated that the maternally-supplied Ascl1 renders embryonic cells a propensity to adopt neural fates on one hand, and represses the mesendoderm formation on the other. However, it remains unclear how Ascl1 achieves its repressor function during the activation of mesendoderm genes by VegT. Here, we performed series of gain- and loss-of-function experiments and found that: (i) VegT, the maternal mesendoderm determinant in Xenopus, is required for the deposition of H3K27ac and H3K9ac at its target gene loci during mesendoderm induction; (ii) Ascl1 and VegT antagonistically modulate the deposition of acetylated histone marks at mesendoderm gene loci; (iii) Ascl1 overexpression reduces the VegT-occupancy at mesendoderm gene loci; (iv) Ascl1 but not Neurog2 possesses a repressive activity during mesendoderm induction. These findings reveal a novel repressive function for Ascl1 in inhibiting non-neural fates during early Xenopus embryogenesis.

The MLL/Setd1b methyltransferase is required for the Spemann's organizer gene activation in Xenopus.

Wdr5 is an essential component of SET/MLL methylase complexes that catalyze histone H3 lysine 4 trimethylation. The maternal Wnt/ß-catenin signaling is necessary for the H3K4me3 deposition at organizer genes in early Xenopus embryos. However, it remains unknown whether any component of SET/MLL methylase complex is required for Wnt signaling to establish H3K4me3 at its targets during the organizer induction. Here, we provide evidence that Wdr5 is required for dorsal axis development and organizer gene activation in Xenopus. Depletion of maternal Wdr5 resulted in ventralized development, phenocopying depletion of maternal ß-catenin. Depletion of maternal Wdr5 also drastically reduced the ability of ß-catenin to activate organizer genes. Siamois, a direct target of maternal Wnt/ß-catenin signaling, was able to reinitiate dorsal axis formation when Wdr5 was depleted. Importantly, we demonstrate that Wdr5 is required for H3K4me3 establishment at the promoter region of siamois. Moreover, we found evidence that Setd1b, a maternally provided methyltransferase, is required for organizer gene expression. Our findings indicate that Wdr5-mediated H3K4 trimethylation plays a part in the organizer formation and dorsal axis development that are controlled by the maternal Wnt/ß-catenin pathway.

NF2/Merlin is required for the axial pattern formation in the Xenopus laevis embryo.

The NF2 gene product Merlin is a FERM-domain protein possessing a broad tumor-suppressing function. NF2/Merlin has been implicated in regulating multiple signaling pathways critical for cell growth and survival. However, it remains unknown whether NF2/Merlin regulates Wnt/ß-catenin signaling during vertebrate embryogenesis. Here we demonstrate that NF2/Merlin is required for body pattern formation in the Xenopus laevis embryo. Depletion of the maternal NF2/Merlin enhances organizer gene expression dependent on the presence of ß-catenin, and causes dorsanteriorized development; Morpholino antisense oligo-mediated knockdown of the zygotic NF2/Merlin shifts posterior genes anteriorwards and reduces the anterior development. We further demonstrate that targeted depletion of NF2 in the presumptive dorsal tissues increases the levels of nuclear ß-catenin in the neural epithelial cells. Biochemical analyses reveal that NF2 depletion promotes the production of active ß-catenin and concurrently decreases the level of N-terminally phosphorylated ß-catenin under the stimulation of the endogenous Wnt signaling. Our findings suggest that NF2/Merlin negatively regulates the Wnt/ß-catenin signaling activity during the pattern formation in early X. laevis embryos.

N- and E-cadherins in Xenopus are specifically required in the neural and non-neural ectoderm, respectively, for F-actin assembly and morphogenetic movements.

Transmembrane cadherins are calcium-dependent intercellular adhesion molecules. Recently, they have also been shown to be sites of actin assembly during adhesive contact formation. However, the roles of actin assembly on transmembrane cadherins during development are not fully understood. We show here, using the developing ectoderm of the Xenopus embryo as a model, that F-actin assembly is a primary function of both N-cadherin in the neural ectoderm and E-cadherin in the non-neural (epidermal) ectoderm, and that each cadherin is essential for the characteristic morphogenetic movements of these two tissues. However, depletion of N-cadherin and E-cadherin did not cause dissociation in these tissues at the neurula stage, probably owing to the expression of C-cadherin in each tissue. Depletion of each of these cadherins is not rescued by the other, nor by the expression of C-cadherin, which is expressed in both tissues. One possible reason for this is that each cadherin is expressed in a different domain of the cell membrane. These data indicate the combinatorial nature of cadherin function, the fact that N- and E-cadherin play primary roles in F-actin assembly in addition to roles in cell adhesion, and that this function is specific to individual cadherins. They also show how cell adhesion and motility can be combined in morphogenetic tissue movements that generate the form and shape of the embryonic organs.

Wnt5a and Wnt11 interact in a maternal Dkk1-regulated fashion to activate both canonical and non-canonical signaling in Xenopus axis formation.

Wnt signaling in development and adult tissue homeostasis requires tight regulation to prevent patterning abnormalities and tumor formation. Here, we show that the maternal Wnt antagonist Dkk1 downregulates both the canonical and non-canonical signaling that are required for the correct establishment of the axes of the Xenopus embryo. We find that the target Wnts of Dkk activity are maternal Wnt5a and Wnt11, and that both Wnts are essential for canonical and non-canonical signaling. We determine that Wnt5a and Wnt11 form a previously unrecognized complex. This work suggests a new aspect of Wnt signaling: two Wnts acting in a complex together to regulate embryonic patterning.

The role of maternal CREB in early embryogenesis of Xenopus laevis.

In Xenopus embryos, body patterning and cell specification are initiated by transcription factors, which are themselves transcribed during oogenesis, and their mRNAs are stored for use after fertilization. We have previously shown that the T-box transcription factor VegT is both necessary and sufficient to initiate transcription of all endoderm, and most mesoderm genes. In the absence of maternal VegT, no mesodermal organs (including the heart) or endodermal organs form. A second maternal transcription factor XTcf3 acts as a global repressor of transcription of dorsal genes, whose repression is inactivated on the dorsal side by a maternally encoded Wnt signaling pathway. In the absence of beta-catenin, no mesodermal or endodermal organs form. We show here that the maternally encoded transcription factor CREB is also essential for development. It is required for the initiation of expression of several mesodermal genes, including Xbra, Xcad2, and -3 and also regulates the cardiogenic gene Nkx 2-5. We show that maternal CREB-depleted embryos develop gastrulation defects that are rescued by the reintroduction of activated CREB mRNA. We conclude that maternal CREB must be added to the list of essential maternal transcription factors regulating cell specification in the early embryo.

Stage-specific expression of breast cancer-specific gene gamma-synuclein.

Gamma-synuclein (SNCG), also referred as breast cancer-specific gene 1, is the third member of a neuronal protein family synuclein. SNCG is highly expressed in human-infiltrating breast carcinomas but not expressed in normal or benign breast tissues. To evaluate the clinical relevance of SNCG expression in breast cancer progression and its correlation with clinical parameters, we analyzed SNCG expression in 79 clinical breast specimens from primary breast cancer, hyperplasia, and fibroadenoma patients by reverse transcription-PCR. The status of estrogen receptor, progesterone receptor, proliferating cell nuclear antigen, and C-erBb2 was also analyzed by immunohistochemistry. Overall SNCG mRNA expression was detectable in 38.8% of breast cancers. However, 79% of stage III/IV breast cancers were positive for SNCG expression, whereas only 15% of stage I/II breast cancers were positive for SNCG expression. In contrast, the expression of SNCG was undetectable in all benign breast lesions. The expression of SNCG was strongly correlated to the stage of breast cancer (P=0.000). This study suggests that the expression of SNCG is stage specific for breast cancer. SNCG is expected to be a useful marker for breast cancer progression and a potential target for breast cancer treatment.

The roles of three signaling pathways in the formation and function of the Spemann Organizer.

Since the three main pathways (the Wnt, VegT and BMP pathways) involved in organizer and axis formation in the Xenopus embryo are now characterized, the challenge is to understand their interactions. Here three comparisons were made. Firstly, we made a systematic comparison of the expression of zygotic genes in sibling wild-type, VegT-depleted (VegT(-)), beta-catenin-depleted (beta-catenin(-)) and double depleted (VegT(-)/beta-catenin(-)) embryos and placed early zygotic genes into specific groups. In the first group some organizer genes, including chordin, noggin and cerberus, required the activity of both the Wnt pathway and the VegT pathway to be expressed. A second group including Xnr1, 2, 4 and Xlim1 were initiated by the VegT pathway but their dorsoventral pattern and amount of their expression was regulated by the Wnt pathway. Secondly, we compared the roles of the Wnt and VegT pathways in producing dorsal signals. Explant co-culture experiments showed that the Wnt pathway did not cause the release of a dorsal signal from the vegetal mass independent from the VegT pathway. Finally we compared the extent to which inhibiting Smad 1 phosphorylation in one area of VegT(-), or beta-catenin(-) embryos would rescue organizer and axis formation. We found that BMP inhibition with cm-BMP7 mRNA had no rescuing effects on VegT(-) embryos, while cm-BMP7 and noggin mRNA caused a complete rescue of the trunk, but not of the anterior pattern in beta-catenin(-) embryos.

Repression through a distal TCF-3 binding site restricts Xenopus myf-5 expression in gastrula mesoderm.

The development of skeletal muscle in the vertebrate embryo is controlled by a transcriptional cascade that includes the four myogenic regulatory factors Myf-5, MyoD, Myogenin, and MRF4. The dynamic expression pattern of myf-5 during myogenesis is thought to be consistent with its role during early determination of the myogenic lineage. To study the factors and mechanisms, which regulate myf-5 transcription in Xenopus, we isolated a genomic DNA clone containing 4858 bp of Xmyf-5 5' flanking region. Using a transgenic reporter assay, we show here that this genomic contig is sufficient to recapitulate the dynamic stage- and tissue-specific expression pattern of Xmyf-5 from the gastrula to tail bud stages. For the primary induction of myf-5 transcription, we identify three main regulatory elements, which are responsible for (i) activation in dorsal mesoderm, (ii) activation in ventral mesoderm, and (iii) repression in midline mesoderm, respectively. Their combined activities define the two-winged expression domain of myf-5 in the preinvoluted mesoderm. Repression in midline mesoderm is mediated by a single TCF binding site located in the 5' end of the -4.8 kbp sequence, which binds XTcf-3 protein in vitro. Endogenous Wnt signaling in the lateral mesoderm is required to overcome the long-range repression through this distal TCF site, and to stimulate myf-5 transcription independently from it. The element for ventral mesoderm activation responds to Activin. Together, these results describe a regulatory mosaic of repression and activation, which defines the myf-5 expression profile in the frog gastrula.