Effects of Alkoxy Chain Length and 1-Hydroxy Group on Anticolorectal Cancer Activity of 2-Bromoalkoxyanthraquinones.

BACKGROUND: KRAS and p53 are two of the most common genetic alterations associated with colorectal cancer. New drug development targeting these mutated genes in colorectal cancer may serve as a potential treatment avenue to the current regimen. OBJECTIVE: The objective of the present study was to investigate the effects of alkoxy chain length and 1-hydroxy group on anticolorectal cancer activity of a series of 2-bromoalkoxyanthraquinones and corroborate it with their in silico properties. METHODS: In vitro anticancer activity of 2-bromoalkoxyanthraquinones was evaluated against HCT116, HT29, and CCD841 CoN cell lines, respectively. Molecular docking was performed to understand the interactions of these compounds with putative p53 and KRAS targets (7B4N and 6P0Z). RESULTS: 2-Bromoalkoxyanthraquinones with the 1-hydroxy group were proven to be more active than the corresponding counterparts in anticancer activity. Among the tested compounds, compound 6b with a C3 alkoxy chain exhibited the most promising antiproliferation activity against HCT116 cells (IC50 = 3.83 ± 0.05 µM) and showed high selectivity for HCT116 over CCD841 CoN cells (SI = 45.47). The molecular docking reveals additional hydrogen bonds between the 1-hydroxy group of 6b and the proteins. Compound 6b has adequate lipophilicity (cLogP = 3.27) and ligand efficiency metrics (LE = 0.34; LLE = 2.15) close to the proposed acceptable range for an initial hit. CONCLUSION: This work highlights the potential of the 1-hydroxy group and short alkoxy chain on anticolorectal cancer activity of 2-bromoalkoxyanthraquinones. Further optimisation may be warranted for compound 6b as a therapeutic agent against colorectal cancer.

A Reverse Structure-based Design of HPV E7 Inhibitor.

BACKGROUND: Human papillomavirus (HPV) is a small, non-enveloped double-stranded circular DNA virus. The high-risk types of HPV are claimed to be responsible for over 99% of cervical cancers. One of the essential HPV oncoproteins, E7, is responsible for escaping from G1/S cell cycle arrest in HPV-infected cells by binding to the retinoblastoma protein (pRb) through its LXCXE binding site. OBJECTIVE: To design a peptide inhibitor targeting HPV E7 through an in silico approach. METHODS: In this study, the LXCXE binding domain of pRb is used as a target to design peptide inhibitors using a reverse structure-based approach. The designed amino acid sequence from the B pocket of pRb, named peptide Y, was further investigated in vitro analysis. The cytotoxicity of the peptide was analysed in two cell lines, namely, CaSki, containing an integrated HPV16 genome, and HaCaT, an immortalized keratinocyte cell. Cell cycle analysis was also carried out in both cell lines treated with peptides. RESULTS: In the in silico approach, a 9-amino acids peptide sequence formed 4 conventional hydrogen bonds with LXCXE motif was selected for in vitro assay. Based on the cytotoxicity analysis, the peptide showed low toxicity in both cell lines, where the cell viability remained over 74% when treated with peptide Y. The peptide also caused an accumulation of cells in G0/G1 (+5.4%) and S phase (+10.2%) and a reduction of cells in the G2/M phase (-14.9%) in the CaSki cells with no significant effect on normal cells, indicating it is a potential HPV inhibitor. CONCLUSION: A peptide inhibitor, peptide Y, that was designed from the LXCXE binding motif in pRb can inhibit HPV E7 by causing a cell accumulation effect in G0/G1, and S phases of the cell cycle in the HPV transformed cell lines. These findings could contribute to HPV E7 peptide inhibitor in the future.

The Pandemic of Coronavirus Disease 2019 (COVID-19).

Currently, the world is facing the emergence of a virus that causes pneumonia in humans, which has a higher probability of causing complications, including respiratory distress syndrome and death. The new coronavirus 2019 (2019-nCoV), which is currently known as SARS-CoV-2, is the cause of the Coronavirus disease 2019 (COVID-19). This virus was first detected in Wuhan, Hubei Province of China, and appears to have been a zoonotic infection that has now adapted to humans. On March 11, 2020, COVID-19 was announced as a pandemic by the World Health Organisation (WHO), causing widespread panic worldwide. SARS-CoV-2 is genetically similar to the 2003 Severe Acute Respiratory Syndrome-related (SARS) and shares many similarities with the disease features of influenza virus infection. Scientists around the world are racing towards the development of vaccines and antivirals for COVID-19. This review will provide an update of COVID-19, a brief review of the symptoms and route of transmission of the SARS-CoV-2 virus, the reason why it is highly infectious, as well as the currently available treatments and comorbidities.

The ABA392/pET30a protein of Pasteurella multocida provoked mucosal immunity against HS disease in a rat model.

Haemorrhagic septicaemia (HS) is a well-known high fatality septicaemic disease happening among bovines. The disease is caused by the Pasteurella multocida serotype B:2 bacteria. P. multocida B:2 has high mortality and morbidity rates and is spread through the intranasal and oral routes in bovines. In this study, our aim was to investigate the efficacy of the recombinant protein vaccine, ABA392/pET30a via intranasal inoculation by targeting the mucosal immunity. The constructed recombinant protein vaccine ABA392/pET30a was subjected to an animal study using Sprague Dawley rats. The study was divided into two parts: active and passive immunization studies. Both studies were carried out through the determination of immunogenicity (using Total White Blood Cell (TWBC) Count with Indirect ELISA) and histopathogenicity, analyzing (Bronchus Associated Lymphoid Tissue (BALT) formation) in lungs. As a result, the IgA and IgG development of both tested groups: group 1 (50µg/mL protein vaccine) and group 2 (100µg/mL protein vaccine) showed equivalent with the positive control group 4 (formalin-killed P. multocida B:2). However, there was a significant difference when compared with the negative control group 3 (normal saline). These results demonstrate that both the protein vaccine at the concentration 50µg/mL and 100µg/mL have the same efficacy as the commercially available positive control vaccine. From the studies, higher concentration of protein vaccine at 100µg/mL showed higher development of both IgA and IgG compared to 50µg/mL protein vaccine. Higher and rapid development of IgA compared to IgG showed that mucosal immunity has been induced through the intranasal administration of the protein vaccine. In addition, leucocytosis was observed at each dose of vaccination showed that the protein vaccine is capable to induce the immune responses of the host. Histopathogenicity studies of the vaccinated groups showed more BALT formation and no severe lesions after challenge compared to the negative control group. Besides, no inflammatory onsite or anaphylactic responses were observed after the intranasal inoculation which proved to be safer and provided longer lasting immunity. Therefore, recombinant protein vaccine ABA392/pET30a could be a potential candidate for intranasal administration which can provoke mucosal immunity against HS disease.

Mefenamic acid in combination with ribavirin shows significant effects in reducing chikungunya virus infection in vitro and in vivo.

Chikungunya virus (CHIKV) infection is a persistent problem worldwide due to efficient adaptation of the viral vectors, Aedes aegypti and Aedes albopictus mosquitoes. Therefore, the absence of effective anti-CHIKV drugs to combat chikungunya outbreaks often leads to a significant impact on public health care. In this study, we investigated the antiviral activity of drugs that are used to alleviate infection symptoms, namely, the non-steroidal anti-inflammatory drugs (NSAIDs), on the premise that active compounds with potential antiviral and anti-inflammatory activities could be directly subjected for human use to treat CHIKV infections. Amongst the various NSAID compounds, Mefenamic acid (MEFE) and Meclofenamic acid (MECLO) showed considerable antiviral activity against viral replication individually or in combination with the common antiviral drug, Ribavirin (RIBA). The 50% effective concentration (EC50) was estimated to be 13 µM for MEFE, 18 µM for MECLO and 10 µM for RIBA, while MEFE + RIBA (1:1) exhibited an EC50 of 3 µM, and MECLO + RIBA (1:1) was 5 µM. Because MEFE is commercially available and its synthesis is easier compared with MECLO, MEFE was selected for further in vivo antiviral activity analysis. Treatment with MEFE + RIBA resulted in a significant reduction of hypertrophic effects by CHIKV on the mouse liver and spleen. Viral titre quantification in the blood of CHIKV-infected mice through the plaque formation assay revealed that treatment with MEFE + RIBA exhibited a 6.5-fold reduction compared with untreated controls. In conclusion, our study demonstrated that MEFE in combination with RIBA exhibited significant anti-CHIKV activity by impairing viral replication in vitro and in vivo. Indeed, this finding may lead to an even broader application of these combinatorial treatments against other viral infections.

The association of mammalian DREAM complex and HPV16 E7 proteins.

The mammalian DREAM (Drosophila, RB, E2F, and Myb) complex was discovered in 2004 by several research groups. It was initially identified in Drosophila followed by Caenorhaditis elegans and later in mammalian cells. The composition of DREAM is temporally regulated during cell cycle; being associated with E2F-4 and either p107 or p130 in G0/G1 (repressive DREAM complexes) and with B-myb transcription factor in S/G2 (activator DREAM complex). High risk human papillomavirus (HPV) E6 and E7 oncoproteins expression are important for malignant transformation of cervical cancer cells. In particular, the E7 of high risk HPV binds to pRB family members (pRB, p107 and p130) for degradation. It has recently been discovered that the p107 and p130 'pocket proteins' are members of mammalian DREAM complexes. With this understanding, we would like to hypothesise the mammalian DREAM complex could plays a critical role for malignant transformation in cervical cancer cells.

A B-myb--DREAM complex is not critical to regulate the G2/M genes in HPV-transformed cell lines.

BACKGROUND/AIM: It is well-established that HPV E7 proteins, encoded by human papillomavirus (HPV) genes, frequently associated with cervical cancers bind avidly to the retinoblastoma (RB) family of pocket proteins and disrupt their association with members of the E2F transcription factor family. Our previous study showed that the repressive p130-dimerization partner, RB-like, E2F and multi-vulval class (DREAM) complex was disrupted by HPV16 E7 proteins in order to maintain the viral replication in CaSki cells. However, we would like to address whether the activator B-myb-DREAM complex is critical in regulating the replication and mitosis phase since our previous study showed increased B-myb-DREAM expression in HPV-transformed cell lines when compared to control cells. RESULTS: The association of B-myb with both LIN-54 and LIN-9 was equally decreased by depleting LIN-54 in CaSki cells. Flow cytometry analysis showed that LIN-54 depletion caused an increased proportion of G2/M cells in T98G, SiHa and CaSki cells. The mRNA levels of certain S/G2 genes such as cyclin B, aurora kinase A and Polo-like kinase 1 have demonstrated a marginal increased in CaSki-Lin-54-depleted cells when compared to SiHa- and T98G-Lin-54-depleted cells. We further confirmed this experiment by depleting the B-myb itself in CaSki cells and the results showed the same pattern of cell cycle and mRNA levels for S/G2 genes when compared to LIN-54- and LIN-9-depleted cells. CONCLUSION: The B-myb-DREAM complex might not be vital for progression through mitosis in cells lacking a G1/S checkpoint and not as crucial as the p130-DREAM complex for the survival of the HPV virus.