Advances in inducing adaptive immunity using cell-based cancer vaccines: clinical applications in pancreatic cancer

The incidence of pancreatic ductal adenocarcinoma(PDA) is on the rise, and the prognosis is extremely poor because PDA is highly aggressive and notoriously difficult to treat. Although gemcitabine- or 5-fluorouracil-based chemotherapy is typically offered as a standard of care, most patients do not survive longer than 1 year. Therefore, the development of alternative therapeutic approaches for patients with PDA is imperative. As PDA cells express numerous tumor-associated antigens that are suitable vaccine targets, one promising treatment approach is cancer vaccines. During the last few decades, cell-based cancer vaccines have offered encouraging results in preclinical studies. Cell-based cancer vaccines are mainly generated by presenting whole tumor cells or dendritic cells to cells of the immune system. In particular, several clinical trials have explored cell-based cancer vaccines as a promising therapeutic approach for patients with PDA. Moreover, chemotherapy and cancer vaccines can synergize to result in increased efficacies in patients with PDA. In this review, we will discuss both the effect of cell-based cancer vaccines and advances in terms of future strategies of cancer vaccines for the treatment of PDA patients.

A mutation of the start codon in the X region of hepatitis B virus DNA in a patient with non-B,non-C chronic hepatitis

There are cases of hepatitis involving occult hepatitis B virus(HBV)infection in which,even though the HB surface antigen(HBsAg)is negative,HBV-DNA is detected by a polymerase chain reaction(PCR).We con-ducted a sequence analysis of the entire HBV region in a case of non-B non-C chronic hepatitis in a 46-yearold female.A diagnosis of non-B non-C chronic hepatitis was made.Although HBV markers,such as HBs antibody(anti-HBs),anti-HBc,HBeAg and anti-HBe,were negative,HBV-DNA was positive.Nested PCR was performed to amplify the precore region of HBV-DNA and all remaining regions by long nested PCR.Sequence analysis of the two obtained bands was conducted by direct sequencing.Compared with the control strains,the ATG(Methionine)start codon in the X region had mut ated to GTG(Valine).It is assumed that a mutation at the start codon in the X region may be the reason why HBV markers are negative in some cases of hepatitis that involve occult HBV infection.

Prognostic significance of plasma interleukin-6/-8 in pancreatic cancer patients receiving chemoimmunotherapy

AIM: To investigate the association of plasma levels of interleukin(IL)-6 and-8 with Wilms' tumor 1(WT1)-specific immune responses and clinical outcomes in patients with pancreatic ductal adenocarcinoma(PDA) treated with dendritic cells(DCs) pulsed with three types of major histocompatibility complex classⅠand Ⅱ-restricted WT1 peptides combined with chemotherapy.METHODS: During the entire treatment period, plasma levels of IL-6 and-8 were analyzed by ELISA. The induction of WT1-specific immune responses was assessed using the WT1 peptide-specific delayed-type hypersensitivity(DTH) test.RESULTS: Three of 7 patients displayed strong WT1-DTH reactions throughout long-term vaccination with significantly decreased levels of IL-6/-8 after vaccinations compared with the levels prior to treatment. Moreover, overall survival(OS) was significantly longer in PDA patients with low plasma IL-6 levels(< 2 pg/m L) after 5 vaccinations than in patients with high plasma IL-6 levels(≥ 2 pg/m L)(P = 0.025). After disease progression, WT1-DTH reactions decreased severely and were ultimately negative at the terminal stage of cancer. The decreased levels of IL-6/-8 observed throughout long-term vaccination were associated with WT1-specific DTH reactions and long-term OS.CONCLUSION: Prolonged low levels of plasma IL-6/-8 in PDA patients may be a prognostic marker for the clinical outcomes of chemoimmunotherapy.

Peginterferon and ribavirin treatment for hepatitis C virus infection

Pegylated interferon α (IFNα) in combination with ribavirin is currently recommended as a standard-of-care treatment for chronic hepatitis C virus (HCV) infection. This combination therapy has drastically improved the rate of sustained virological response, specifically in difficult-to-treat patients. Recently, individualized treatment, such as response-guided therapy, is being developed based on host-, HCV- and treatment-related factors. Furthermore, modified regimens with currently available medications, novel modified IFNα and ribavirin or combinations with specifically targeted antiviral therapy for HCV agents, are currently being investigated. The purpose of this review is to address some issues and epoch-making topics in the treatment of chronic HCV infection, and to discuss more optimal and highly individualized therapeutic strategies for HCV-infected patients.

Immunotherapy for colorectal cancer

The incidence of colorectal cancer(CRC)is on the rise,and the prognosis for patients with recurrent or metastatic disease is extremely poor.Although chemotherapy and radiation therapy can improve survival rates,it is imperative to integrate alternative strategies such as immunotherapy to improve outcomes for patients with advanced CRC.In this review,we will discuss the effect of immunotherapy for inducing cytotoxic T lymphocytes and the major immunotherapeutic approaches for CRC that are currently in clinical trials,including peptide vaccines,dendritic cell-based cancer vaccines,whole tumor cell vaccines,viral vector-based cancer vaccines,adoptive cell transfer therapy,antibody-based cancer immunotherapy,and cytokine therapy.The possibility of combination therapies will also be discussed along with the challenges presented by tumor escape mechanisms.

Early apoptosis and cell death induced by ATX-S10Na(Ⅱ)-mediated photodynamic therapy are Bax- and p53-dependent in human colon cancer cells

AIM： To investigate the roles of Bax and p53 proteins in photosensitivity of human colon cancer cells by using lysosome-localizing photosensitizer, ATX-S10Na （Ⅱ）. METHODS： HCT116 human colon cancer cells and Bax-null or p53-null isogenic derivatives were irradiated with a diode laser. Early apoptosis and cell death in response to photodynamic therapy were determined by MTT assays, annexin Ⅴ assays, transmission electron microscopy assays, caspase assays and western blotting. RESULTS： Induction of early apoptosis and cell death was Bax- and p53-dependent. Bax and p53 were required for caspase-dependent apoptosis. The levels of anti-apoptotic Bcl-2 family proteins, Bcl-2 and Bcl-xL, were decreased in Bax- and p53-independent manner. CONCLUSION： Our results indicate that eady apoptosis and cell death of human colon cancer cells induced by photodynamic therapy with lysosome-localizing photosensitizer ATX-S10Na （Ⅱ） are mediated by p53- Bax network and low levels of Bcl-2 and Bcl-xL proteins. Our results might help in formulating new therapeutic approaches in photodynamic therapy.

Dendritic cell-based cancer immunotherapy for colorectal cancer

Colorectal cancer(CRC) is one of the most common cancers and a leading cause of cancer-related mortality worldwide. Although systemic therapy is the standard care for patients with recurrent or metastatic CRC, the prognosis is extremely poor. The optimal sequence of therapy remains unknown. Therefore, alternative strategies, such as immunotherapy, are needed for patients with advanced CRC. This review summarizes evidence from dendritic cell-based cancer immunotherapy strategies that are currently in clinical trials. In addition, we discuss the possibility of antitumor immune responses through immunoinhibitory PD-1/PD-L1 pathway blockade in CRC patients.

Four-week pegylated interferon a-2a monotherapy for chronic hepatitis C with genotype 2 and low viral load:A pilot,randomized study

AIM:To assess the efficacy and advantages of 4-wk pegylated interferon a-2a(peg-IFN-a2a) monotherapy for chronic hepatitis C patients with strong predictors of sustained virologic response(SVR).METHODS:Patients(n = 33) with genotype 2 and low viral load(< 100 KIU/mL),who became HCV RNA negative after 1 wk of IFN treatment,were randomly allocated to receive a 4-or 12-wk treatment course at a ratio of 2:1,respectively,with a subsequent 24-wk follow-up period.Peg-IFN-a2a was administered subcutaneously at a dose of 180 μg or 90 μg once weekly.SVR was defined as absence of serum HCV RNA at the end of the follow-up period.RESULTS:All patients completed the treatment schedule,and more than half were symptom-free during the treatment.In the 4-wk treatment group,20 of 22(91%) patients achieved SVR.Two patients relapsed,but achieved SVR following re-treatment with peg-IFN-a2a alone.In the 12-wk treatment group,11 of 11(100%) patients attained SVR.CONCLUSION:Our results show that a 4-wk course of peg-IFN-a2a monotherapy can achieve a high SVR rate in "IFN-sensitive" patients,without negatively affecting outcome.

Several factors including ITPA polymorphism influence ribavirin-induced anemia in chronic hepatitis C

AIM： To construct formulae for predicting the likelihood of ribavirin-induced anemia in pegylated interferon plus ribavirin for chronic hepatitis C. METHODS： Five hundred and sixty-one Japanese patients with hepatitis C virus genotype lb who had received combination treatment were enrolled and as- signed randomly to the derivation and confirmatory groups. Single nucleotide polymorphisms at or nearby ITPA were genotyped by real-time detection poly- merase chain reaction. Factors influencing significant anemia （hemoglobin concentration 〈 10.0 g/dL at week 4 of treatment） and significant hemoglobin decline （declining concentrations 〉 3.0 g/dL at week 4） were analyzed using multiple regression analyses. Prediction formulae were constructed by significantly independent factors. RESULTS： Multivariate analysis for the derivation group identified four independent factors associated with significant hemoglobin decline： hemoglobin decline at week 2 [P = 3.29× 10^4, odds ratio （OR） = 7.54 （g/dL）], estimated glomerular filtration rate [P = 2.16× 10^4, OR = 0.962 （ml/min/1.73 m2）], rs1127354 （P = 5.75 × 10^4, OR = 10.94） and baseline hemoglobin [P = 7.86 × 10^4, OR = 1.50 （g/alL）]. Using the model constructed by these factors, positive and negative predictive values and predictive accuracy were 79.8%, 88.8% and 86.2%, respectively. For the confirmatory group, they were 83.3%, 91.0% and 88.3%. These factors were closely correlated with significant anemia. However, the model could not be constructed, because no patients with rs1127354 minor genotype CA/AA had significant anemia. CONCLUSION： Reliable formulae for predicting the likelihood of ribavirin-induced anemia were constructed. Such modeling may be useful in developing individual tailoring and optimization of ribavirin dosage.

Platelet count and sustained virological response in hepatitis C treatment

AIM:To examine the epidemiological data,hematological safety and treatment responses of peginterferonalpha 2a plus ribavirin therapy for hepatitis C.METHODS:Between March 2008 and February 2011,196 hepatitis C virus(HCV)genotype 1 infected Japanese(127 treatment-naive and 69 treatment-experienced patients)patients treated with peginterferonalpha 2a plus ribavirin were enrolled.We examined the epidemiological data and treatment responses were retrospectively analyzed in terms of hematological safety.HCV RNA was measured by the COBAS TaqMan HCV test.RESULTS:Overall sustained virological response(SVR)rates of treatment-naive and treatment-experienced patients were 56% and 39%,respectively.Multivariate logistic regression analysis showed that SVR was attained independently of early virological response in both treatment-naive and treatment-experienced patients.SVR rates did not differ between the pretreatment hemoglobin < 13 g/dL and ≥ 13 g/dL groups.However,in treatment-naive patients,the SVR rate of the pretreatment platelet count < 130000/μL group was significantly lower than that of the pretreatment platelet count ≥ 130000/μL group.CONCLUSION:Attention should be paid to potential thrombocytopenia in the treatment of chronic hepatitis C patients.

A multifunctional scaffold that promotes the scaffold-tissue interface integration and rescues the ROS microenvironment for repair of annulus fibrosus defects

Due to the limited self-repair ability of the annulus fibrosus (AF), current tissue engineering strategies tend to use structurally biomimetic scaffolds for AF defect repair. However, the poor integration between implanted scaffolds and tissue severely affects their therapeutic effects. To solve this issue, we prepared a multifunctional scaffold containing loaded lysyl oxidase (LOX) plasmid DNA exosomes and manganese dioxide nanoparticles (MnO2 NPs). LOX facilitates extracellular matrix (ECM) cross-linking, while MnO2 NPs inhibit excessive reactive oxygen species (ROS)-induced ECM degradation at the injury site, enhancing the crosslinking effect of LOX. Our results revealed that this multifunctional scaffold significantly facilitated the integration between the scaffold and AF tissue. Cells were able to migrate into the scaffold, indicating that the scaffold was not encapsulated as a foreign body by fibrous tissue. The functional scaffold was closely integrated with the tissue, effectively enhancing the mechanical properties, and preventing vascular invasion, which emphasized the importance of scaffold-tissue integration in AF repair.

Evolutionary characteristics of SARS-CoV-2 Omicron subvariants adapted to the host

Dear Editor,As the COVID-19 epidemic proceeds,new variants of SARS-CoV-2 continue to emerge.^(1)Particularly the B.1.1.529(Omicron)variant emerged and spread globally,surpassing the previously dominant B.1.617.2(Delta)variant.Moreover,the original Omicron variant continued to mutate into numerous Omicron sublineages.Nonetheless,the infectious and immune characteristics of newly-emerged Omicron sublineages that have evolved to adapt to the host remain unclear.

Omicron adopts a different strategy from Delta and other variants to adapt to host

Dear Editor,With the ongoing of Corona Virus Disease 2019(COVID-19)epidemic,new strains of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)are continuously emerging.After Delta(B.1.617.2)identified in India,Lambda(C.37),Mu(B.1.621),and Omicron(B.1.1.529)were successively found in Peru,Colombia,and Botswana/South Africa,and subsequently defined as variant of interest(VOI)or variant of concern(VOC).