1. Introduction
Prostatitis, the third most common urological disorder in males, affects 10-14 % of men of all ages and ethnic origins. Prostatitis has been found to be associated with the genesis of Benign Prostatic Hyperplasia (BPH), a condition that represents an important risk for the development and progression of prostate cancer (PCa) [
1,
2,
3,
4,
5]. BPH prevalence increases after the age of 40 years, from 8% up to 60% at 90 years old [
6]. According to the International Agency for Research on Cancer (IARC), in 2020, there were an estimated 1.4 million new cases of PCa worldwide, making it the second most diagnosed cancer in men [
7].
Currently, it has been reported that in BPH, there is no direct relationship between the presence of HPV in the prostate and the development of PCa, as indicated by Bergh et al. [
8]. Additionally, research by Adami et al. [
9] and Effert et al. [
10] suggests that there is no direct association between HPV types 16 or 18 and PCa, though a potential link between HPV type 33 and this disease has been observed.
Contrastingly, other research groups have detected HPV infection in prostate tissue samples, as exemplified by the Singh study [
11]. They analyzed 95 PCa and 55 BPH samples. HPV infection was found in 41% of the prostate tumor biopsies and 20% in BPH samples. Specifically, 32% were infected with HPV type 16, and 6% with type 18, while only 5% of BPH controls had HPV 16. A significant proportion of HPV-infected cases were in advanced stages III and IV with high Gleason scores. This study suggests that HPV infection may be a cofactor in PCa progression.
Different studies have shown a strong correlation between high-risk human papillomavirus (HR-HPV) infection and the increased risk of PCa development. Despite this, the specific mechanisms through which these infections contribute to inflammatory lesions and the hyperproliferation in the prostate gland remain not fully elucidated [
3,
11,
12]. Tumor development in the prostate is a complex process that involves successive changes in the genome of normal prostate cells until they transform into malignant cells. Chronic inflammation is regarded as the seventh hallmark of carcinogenesis and as a possible trigger for tumor initiation and progression at the cellular and molecular levels [
13]. During pro-tumor inflammation, several inflammatory molecules are either activated or suppressed for a prolonged time, leading to undesirable consequences that encourage the growth and enrichment of aggressive tumor phenotypes in the tumor microenvironment [
14]. This process stimulates the infiltration of immune cells and the production of chemokines, cytokines, and free radicals, which can damage DNA and activate the androgen receptor (AR) in prostatic cells [
15,
16,
17].
The expression of various micro-RNAs (miRNAs) has been associated with the progression and appearance of different types of cancer, including prostate, breast, lung, liver, gastric, pancreatic, and colorectal, among others [
18,
19]. Several studies have demonstrated the crucial role of miRNAs in the pathogenesis of cancer. Specifically, miR-34a, miR-106a, miR-143, miR-145, and miR-221 have garnered significant attention in cancer biology. These miRNAs have been implicated in regulating critical processes such as cell proliferation, apoptosis, differentiation, inflammatory response, angiogenesis, tumor suppression, adhesion, metastasis, and immune system evasion [
18,
19,
20,
21,
22,
23].
Particularly, the viral proteins E6 and E7 of HPV play a crucial role in altering genetic regulation in infected cells, specifically affecting miRNAs associated with PCa and tumorigenesis. E6 binds to the p53 protein, a key tumor regulator, promoting its degradation and affecting the expression of miRNAs regulated by p53 [
24]. Both E6 and E7 also interfere with the cellular machinery for processing miRNAs, altering their stability and levels. These proteins impact cellular signaling pathways important for cell cycle control and apoptosis, which in turn influences the expression of miRNAs involved in these processes. Additionally, E6 and E7 can modify the transcription of genes, including those encoding miRNAs, either through changes in chromatin or direct interaction with genetic promoters [
25,
26].
Specifically, in PCa, it has been observed that the presence of HR-HPV leads to the aberrant expression of oncogenic and tumor-suppressive miRNAs. The viral proteins E6 and E7 of HPV play a crucial role in this process, interacting with key transcription factors such as c-Myc, p53, and E2F. This interaction modulates the expression of various miRNAs, including the miR-15/16 cluster, the miR-17-92 family, miR-21, miR-23b, miR-34a, miR-106b/93/25 cluster, miR-143/145 cluster, and let-7c [
25,
26]. Furthermore, Chiantore et al. [
25] demonstrated that HPV E6 and E7 oncoproteins affect the expression of certain tumorigenesis-related miRNAs, including miR-18a, miR-19a, miR-34a, and miR-590-5p. They also identified miR-222, a critical miRNA that is often deregulated in various cancers, present in exosomes from cells infected with the HPV [
27].
miRNAs, which originate from a common transcriptional precursor, are subject to the influence of various post-transcriptional factors that determine their final expression. These include precursor processing, efficiency in the generation of mature miRNAs and interactions with regulatory proteins, which are crucial factors for their expression levels. Notably, recent studies have highlighted the importance of transcriptional regulation, especially that mediated by nuclear receptors such as estrogen receptors (ER) and AR, in the modulation of miRNAs in oncological contexts. For instance, it has been observed that the ER interacts with the miR-221/222 gene to inhibit its expression in breast cancers, while in the progression of PCa, miRNAs such as miR-125b, miR-21, and miR-221/222 could be directly regulated by the AR. These findings suggest that in certain prostate pathologies, the predominant influence on the levels of miRNAs interacting with the AR could be of a transcriptional nature, as indicated by these studies [
28].
In the Mexican population, there is a lack of documented studies analyzing the expression of miRNAs and their relationship with the development of prostate benign lesions (BPH and prostatitis) and its progression to PCa. Thus, the aim of this study was to analyze the expression profile of selected miRNAs in HR-HPV-positive patients with BPH/prostatitis and PCa. Our findings suggest that alterations in the expression levels of miR-34a, miR-145, miR-106a, miR-21, and miR-221 correlated with HPV infection, particularly in PCa. These results suggest that HPV infection can disrupt the expression of miRNAs, affecting the critical processes that maintain prostate cellular homeostasis.
3. Discussion
Currently, it is understood that in the process of tumorigenesis of PCa, HPV modulates through its E6 and E7 oncoproteins to intricately modulate the expression of specific miRNAs. This modulation plays a crucial role in the molecular pathways associated with oncogenic processes and cancer development [
27,
28,
29]. Thus, the aim of our investigation was to explore the potential correlation between specific miRNAs associated with cell proliferation, inflammation, cellular malignancy, and the HPV presence in BPH, BPH/prostatitis, and PCa. In this study, the molecular analysis of HPV in PCa samples revealed a significant relationship between HPV infection and prostatic carcinogenesis, particularly with intermediate- and high-risk genotypes. We found that samples with a Gleason score of ≥8 were highly correlated with the presence of the virus. Furthermore, the most frequent HR- and IR-HPV genotypes associated with PCa were 16, 31, and 52; interestingly, LR-HPV genotype 6 was also found in coinfection with IR-HPV or HR-HPV. Conversely, LR-HPV was more frequently detected in benign lesions (BPH alone or with prostatitis) compared to HR-HPV and IR-HPV genotypes. Our results suggest that premalignant and inflammatory lesions increase the risk of developing PCa.
According to Singh et al. [
11] , HPV-16 is the most prevalent genotype found in PCa samples. However, they also identified genotypes 31 and 52. HR-HPV genotypes can lead to malignant tumors even in low viral concentrations. Nonetheless, HPV-16 can reach viral loads much higher than other high-risk genotypes, correlating with the severity of the disease in cervical cancer, as indicated by Swan et al. [
30]. Thus, we believe this may explain why we found HPV-16 to be more common than HPV-18 in PCa samples. While it is well-known that LR-HPV has no oncogenic effect, its role as a promoter of persistent inflammation is reinforced by its presence in premalignant lesions such as BPH and BPH/prostatitis, especially in coinfection with IR-HPV and HR-HPV genotypes. This suggests that chronic inflammation may contribute to the initiation and progression of prostate cancer. Chronic inflammation is associated with higher rates of cellular mutations and genetic alterations, which could drive tumorigenesis [
14]. Epidemiological data indicate that chronic infections and inflammation are linked to over 25% of all cancers [
31], a finding consistent with the observations made by García-Lozano et al. [
32] in cervical cancer.
In this study, we aimed to investigate the expression levels of specific miRNAs in premalignant inflammatory lesions and their association with the oncogenic process, particularly in relation to HPV presence. Our analysis revealed significant statistical differences (p<0.05) in the expression levels of let-7c, miR-34a, miR-221, miR-145, miR-106a, and miR-126 in comparison to control prostatic tissue. Among them, miR-221, miR-145, miR-126, and miR-106a showed the most significant statistical difference (p<0.001).
Of particular interest is the miRNA let-7c, which acts as a tumor suppressor in several cancers, including PCa [
19]. let-7c targets genes such as NRAS, HMGA2, CCND2, c-Myc, HMGA1, AR, and IL6. Moreover, let-7c regulates other genes, such as TRAIL, Caspase 3, and Lin28b, which are associated with apoptosis, the Epithelial–mesenchymal transition (EMT) process, and angiogenesis. The inhibited expression of let-7c in PCa cells leads to overexpression of the androgen receptor (AR), c-Myc, and HMGA2, which are associated with cell proliferation, migration, invasion, and the EMT process [
33,
34,
35,
36,
37,
38]. It is noteworthy that let-7c and let-7a are considered particularly under-expressed in cervical cancer in comparison with other miRNAs, indicating their association with the presence of HPV in carcinogenic tissue [
39,
40,
41,
42].
We also focused on the role of miR-34a as a tumor suppressor that regulates cell differentiation, cell cycle, and apoptosis, as established by previous studies [
43,
44,
45,
46]. Our findings suggest that miRNA-34a expression is downregulated in PCa, resulting in the overexpression of several target genes associated with proliferation, motility, immune system evasion, and cellular senescence, including CDK6, NOTCH-1, MYCN, WNT proteins, BCL2, SIRT1, BIRC5, CD44, NANOG, SOX2, SNAI1, MET, AXIN2, PD-L1, DGKζ, and E2F3 [
44]. Furthermore, our research indicates that miR-34a inhibits the transcription factor E2F3, which regulates survivin protein, thereby inhibiting apoptosis in samples with cervical cancer [
19,
43]. Although there is no scientific evidence that correlates E2F3 and survivin levels with HPV presence in PCa, our study suggests that the low levels of miR-34a and HPV presence in our samples could be associated with high levels of E2F3 and survivin, inhibiting apoptosis of cells and promoting their survival. According to previous studies, miR-34a can inhibit SIRT1 and CD44, which are associated with cell migration, cancer progression, and inflammatory cellular events [
43]. Our findings suggest that low levels of miR-34a could keep the inflammatory events of the cell, promoting the development of gland transformation through the overexpression of targets like CD44. Additionally, the loss of expression of this miRNA has been strongly related to the overexpression of AR and Notch-1, as well as high-grade lesions [
47]. It is worth noting that miR-34a expression depends on p53, and in cancer cells, p53 tends to be lower than in normal cells, as well as miR-34a. In addition, HR-HPV E6 and E7 oncoproteins tend to inhibit miR-34a expression, contributing to the overexpression of its target molecules [
48,
49]. Likewise, miR-21 plays a crucial role in the progression of PCa by regulating apoptosis, promoting cell proliferation, facilitating invasion and metastasis, potentially contributing to therapeutic resistance, and influencing key signaling pathways. Furthermore, miR-21 can alter the tumor microenvironment and the immune response by modulating the expression of cytokines and inflammatory factors [
50]. Interestingly, in our study, we observed a decrease in miR-34a levels and an increase in miR-21 levels among high Gleason grade PCa patients. These findings align with the research conducted by Khatami et al. [
39], who examined tissue samples from 112 PCa patients and 39 controls to detect HPV and evaluate miRNA expression profiles. Remarkably, they reported a significant decrease in miR-34a levels and an increase in miR-21 levels in PCa patients compared to those in control tissue. These observations suggest that miR-34a may play a role in the development and progression of prostate cancer.
Additionally, Stafford et al. [
51] discovered a significant association between elevated miR-21 expression and advanced stages of PCa, as determined by the Gleason scale. This strongly suggests that elevated miR-21 expression could serve as a valuable biomarker for predicting prostate cancer prognosis.
The downregulation of miR-126 has been shown to be associated with various cellular processes such as apoptosis, proliferation, cell migration, adhesion, and metastasis by targeting SIRT1, CDK6, PIK3R2, E-cadherin, ADAM9, and integrins. Additionally, miR-126 targets the inflammatory molecule HMGB1, and its under-expression has been linked to increased inflammatory processes in tissues [
52,
53,
54,
55]. This indicates that the altered expression of miRNAs, such as miR-34a and miR-126, may play a role in the carcinogenic process of prostate cells by linking inflammatory processes to malignant lesions.
On the other hand, miR-221 has been found to inhibit the SOCS3 and IRF2 genes, which suppress the JAK/STAT pathway that is important in the IFN-II-mediated antiviral response [
56,
57]. Our investigation revealed a diminished expression of miR-221, suggesting that the suppression of the JAK/STAT pathway inhibits the antiviral HPV response [
56,
58]. Several studies have reported that the downregulation of miR-221 in PCa could activate the TGFβ pathway, which promotes the development and progression of cancer [
59]. Moreover, the downregulation of miR-221 has been associated with the overexpression of AR, leading to the loss of the ability of the cells to regulate carcinogenic processes [
59]. However, normal expression levels of miR-221 have been found to inhibit IRF2 and SOCS3, suppressing in turn the cell proliferation in androgen-independent PCa tumors, suggesting that miR-221 may be relevant in the control of cell growth [
60].
According to Cui et al. [
61], miR-145 is a tumor suppressor that plays a vital role in regulating various cellular processes such as cell cycle, proliferation, apoptosis, and cell invasion. Furthermore, under-expression of miR-145 is correlated with the transmembrane protease serine 2-ERG fusion (TMPRSS2-ERG) protein in PCa cells and has been shown to regulate the c-Myc gene that is involved in PCa progression [
62]. Under normal conditions, miR-145 participates in anti-inflammatory events through its inhibitory effect on CD40, IL-6, CXCL8, and SMAD3 [
63]. Moreover, the oncoproteins E6 and E7 of HR-HPVs facilitate the sub-expression of miR-145 and BRCA1 through the union between the E2F1 factor and Myc in the promoter region of BRCA. Furthermore, Gunasekharan and Laimins [
64] reported that HPV-31 can control the expression of miR-145 to maintain its replicative cycle within the cell and suggested that the seed region of miR-145 has a strong affinity for HR-HPV genotypes, ensuring maintenance of infection in epithelial tissue.
In oropharyngeal carcinoma, it was reported that the subexpression of miR-199b, miR-143, miR-145, and miR-126 was due to the presence of HPV, identifying that miR-145 has a specific affinity with the ORF region of the E1 gene [
42]. miR-145 is essential in the negative regulation of the replicative cycle of HPV, so the low expression levels of this miRNA are crucial in the tumor formation associated with HPV [
42]. Furthermore, our results suggest that the normal expression of miR-145 has an anti-inflammatory effect in prostate cells. However, its subexpression in inflammatory lesions (BPH or BPH/prostatitis) could contribute to the transformation of cancer cells along with the deregulated expression of the miRNAs mentioned above.
Shen et al. [
65] found that the under-expression of miR-106a is related to the overexpression of IL-8 in PCa cells. IL-8 is a molecule that promotes prostate tumorigenesis and is a direct target of miR-106a. IL-8 is also known as a primary inflammatory cytokine that facilitates cellular adhesion, neutrophil, and monocyte migration, as well as chronic inflammatory processes. The oncoprotein E6 of HPV positively regulates the expression of IL-8, which is associated with MMP-2 and MMP-9 metalloproteases [
66]. If HR-HPVs increase IL-8, our findings about the HPV presence in PCa samples could explain the downregulation of miR-106a. In summary, the deregulation of miR-34a, miR-221, miR-145, and miR-106a in both chronic inflammatory lesions and PCa positive for HPV strongly suggests their participation in the development of the pro-oncogenic microenvironment.
In summary, in
Figure 6 we propose a possible mechanism of miRNA expression and their role in viral protein modulation and malignant prostate transformation. According to the results, the deregulation of miR-34a, miR-221, miR-145, and miR-106a in chronic inflammatory lesions in samples of BPH/prostatitis and HPV-positive prostate cancer clearly suggests their participation in the pro-oncogenic microenvironment through the alteration of various molecular pathways.
Ongoing studies will elucidate whether these miRNAs are potential candidates as biomarkers for prognosis, diagnosis, or therapeutic targets in HPV-associated prostate cancer. These investigations are essential for establishing their clinical relevance and potentially paving the way for novel therapeutic strategies in the treatment of this disease.
Author Contributions
Conceptualization, Sandra Salgado-Hernández, Lucero Martínez-Retamoza, María Gómez-García and David Pérez-Ishiwara; Data curation, Sandra Salgado-Hernández, Lucero Martínez-Retamoza, Gladys Cedeño-Arboleda and David Pérez-Ishiwara; Formal analysis, Sandra Salgado-Hernández, Lucero Martínez-Retamoza, Rodolfo Ocádiz-Delgado, Salvador Pérez-Mora, Gladys Cedeño-Arboleda, María Gómez-García and David Pérez-Ishiwara; Funding acquisition, María Gómez-García and David Pérez-Ishiwara; Investigation, Sandra Salgado-Hernández, Lucero Martínez-Retamoza, Rodolfo Ocádiz-Delgado, Salvador Pérez-Mora and David Pérez-Ishiwara; Methodology, Sandra Salgado-Hernández, Lucero Martínez-Retamoza, Rodolfo Ocádiz-Delgado, María Gómez-García, Patricio Gariglio and David Pérez-Ishiwara; Project administration, David Pérez-Ishiwara; Resources, María Gómez-García and David Pérez-Ishiwara; Software, Sandra Salgado-Hernández, Lucero Martínez-Retamoza, Rodolfo Ocádiz-Delgado and Patricio Gariglio; Supervision, Rodolfo Ocádiz-Delgado and David Pérez-Ishiwara; Validation, Sandra Salgado-Hernández, Rodolfo Ocádiz-Delgado, María Gómez-García and David Pérez-Ishiwara; Visualization, Sandra Salgado-Hernández, Rodolfo Ocádiz-Delgado, María Gómez-García and David Pérez-Ishiwara; Writing – original draft, Sandra Salgado-Hernández, Lucero Martínez-Retamoza and Salvador Pérez-Mora; Writing – review & editing, Sandra Salgado-Hernández, Rodolfo Ocádiz-Delgado, Salvador Pérez-Mora and David Pérez-Ishiwara.
Figure 1.
Hematoxylin and Eosin in histopathological analysis of benign and PCa Samples. (a) Representative images of the tissue architecture of control samples. Benign Prostatic Hyperplasia (BPH); and Benign Prostate Hyperplasia plus prostatitis (BPH/prostatitis). The BPH and BPH/prostatitis tissues exhibit an increase in epithelial growth with enlarged nuclei restricted to the basal layer (indicated by black arrows). Some patients display a significant inflammatory infiltrate (indicated by red arrows); while in other samples, both conditions may be observed, with cells presenting prominent nuclei in the basal and suprabasal layers, along with an inflammatory infiltrate. (b) Representative images of prostate tissue architecture in prostatic carcinogenic tissue from low, intermediate, and high Gleason grade PCa. To facilitate visual comparison and analysis, the important structures in the tissue, such as acinar lumen (1), luminal cells (2), stroma (3), and cellular organization (4), have been labeled with corresponding numbers. The scale bar indicates 200 and 50 micrometers (µm).
Figure 1.
Hematoxylin and Eosin in histopathological analysis of benign and PCa Samples. (a) Representative images of the tissue architecture of control samples. Benign Prostatic Hyperplasia (BPH); and Benign Prostate Hyperplasia plus prostatitis (BPH/prostatitis). The BPH and BPH/prostatitis tissues exhibit an increase in epithelial growth with enlarged nuclei restricted to the basal layer (indicated by black arrows). Some patients display a significant inflammatory infiltrate (indicated by red arrows); while in other samples, both conditions may be observed, with cells presenting prominent nuclei in the basal and suprabasal layers, along with an inflammatory infiltrate. (b) Representative images of prostate tissue architecture in prostatic carcinogenic tissue from low, intermediate, and high Gleason grade PCa. To facilitate visual comparison and analysis, the important structures in the tissue, such as acinar lumen (1), luminal cells (2), stroma (3), and cellular organization (4), have been labeled with corresponding numbers. The scale bar indicates 200 and 50 micrometers (µm).
Figure 2.
Histological identification of koilocytes and in situ molecular detection of HPV sequences in BPH samples. Panel (a) displays the presence of koilocytes (black arrows), while panel (b) demonstrates the detection of HR-HPV E6/E7 DNA via in situ PCR. The signal was mainly localized in the cell nucleus (black arrows), with a positive signal of HPV DNA amplification detected in koilocytes (empty arrows with letter K). Patient control numbers are indicated. Samples 97 and 3680 were included as negative controls for HPV. Amplification: 40X and 63X. The obtained signal was digitally quantified and displayed in panel (c). Statistical analysis was performed using one-way ANOVA with Tukey’s multiple comparison test, and the results are presented as mean ± standard deviation. The asterisk symbol (*) indicates a significant difference between HPV-positive and HPV-negative samples, with a significance level of * p<0.033.
Figure 2.
Histological identification of koilocytes and in situ molecular detection of HPV sequences in BPH samples. Panel (a) displays the presence of koilocytes (black arrows), while panel (b) demonstrates the detection of HR-HPV E6/E7 DNA via in situ PCR. The signal was mainly localized in the cell nucleus (black arrows), with a positive signal of HPV DNA amplification detected in koilocytes (empty arrows with letter K). Patient control numbers are indicated. Samples 97 and 3680 were included as negative controls for HPV. Amplification: 40X and 63X. The obtained signal was digitally quantified and displayed in panel (c). Statistical analysis was performed using one-way ANOVA with Tukey’s multiple comparison test, and the results are presented as mean ± standard deviation. The asterisk symbol (*) indicates a significant difference between HPV-positive and HPV-negative samples, with a significance level of * p<0.033.
Figure 3.
miRNA expression levels in HPV-negative (−) or HPV-positive (+) benign prostatic samples. Expression of indicated miRNAs in BPH (a) or in BPH/prostatitis (b) is shown. The expression data were normalized using RNU48 as an internal control. Statistical analysis was performed using the multiple T-tests per row. The error bars represent the standard deviation. Three levels of significance were used for p-values: *p<0.033, **p<0.002, and ***p<0.001.
Figure 3.
miRNA expression levels in HPV-negative (−) or HPV-positive (+) benign prostatic samples. Expression of indicated miRNAs in BPH (a) or in BPH/prostatitis (b) is shown. The expression data were normalized using RNU48 as an internal control. Statistical analysis was performed using the multiple T-tests per row. The error bars represent the standard deviation. Three levels of significance were used for p-values: *p<0.033, **p<0.002, and ***p<0.001.
Figure 4.
miRNAs expression levels in HPV-positive PCa samples compared to their expression in control prostate tissue. Statistical analysis was performed using the multiple T-tests per row. The error bars represent the standard deviation. Three levels of significance were employed for p-values: *p<0.033, **p<0.002, and ***p<0.001.
Figure 4.
miRNAs expression levels in HPV-positive PCa samples compared to their expression in control prostate tissue. Statistical analysis was performed using the multiple T-tests per row. The error bars represent the standard deviation. Three levels of significance were employed for p-values: *p<0.033, **p<0.002, and ***p<0.001.
Figure 5.
Distribution of miRNA expression in high-risk (HR)-, low-risk (LR)- and intermediate-risk (IR)-HPV-PCa samples, compared to HPV-negative (NEG) PCa samples. Statistical analysis was performed using the Dunnett multiple comparison test. The p-values were reported as *p<0.033, **p<0.002, and ***p<0.001 for three levels of significance. Error bars represent the standard deviation.
Figure 5.
Distribution of miRNA expression in high-risk (HR)-, low-risk (LR)- and intermediate-risk (IR)-HPV-PCa samples, compared to HPV-negative (NEG) PCa samples. Statistical analysis was performed using the Dunnett multiple comparison test. The p-values were reported as *p<0.033, **p<0.002, and ***p<0.001 for three levels of significance. Error bars represent the standard deviation.
Figure 6.
Schematic overview of miRNAs potential role in HPV infection and prostate cancer progression. miRNAs such as miR-34a, miR-143, and miR-145 are frequently dysregulated in tissues affected by HPV, influencing key cellular processes like apoptosis and cell cycle arrest through their interactions with HPV oncoproteins E6 and E7. E6 leads to the degradation of p53, disrupting various miRNAs that emulate p53 functions, while E7 impedes the retinoblastoma (Rb) protein, altering E2F transcription factor activities. This miRNA dysregulation plays a crucial role in cancer progression by affecting multiple signaling pathways. Specifically, miR-34a and miR-145 suppress androgen receptor (AR) levels, and miR-21, miR-106a, and the miR-221/222 cluster target PTEN, leading to activation of the PI3K/AKT/mTOR pathway. These alterations enhance cellular proliferation, invasion, epithelial-mesenchymal transition (EMT), and metastasis. Importantly, let-7c and miR-143 downregulate the PI3K/AKT pathway, mitigating tumor growth. Moreover, miR-21 and the miR-221/222 cluster also interact with the JAK/STAT pathway, where they influence inflammatory and immune responses, further contributing to prostate cancer progression. Collectively, miRNAs are pivotal in mediating HPV’s oncogenic effects in prostate cancer by regulating essential signaling pathways, highlighting their potential as both biomarkers and therapeutic targets in the management of the disease.
Figure 6.
Schematic overview of miRNAs potential role in HPV infection and prostate cancer progression. miRNAs such as miR-34a, miR-143, and miR-145 are frequently dysregulated in tissues affected by HPV, influencing key cellular processes like apoptosis and cell cycle arrest through their interactions with HPV oncoproteins E6 and E7. E6 leads to the degradation of p53, disrupting various miRNAs that emulate p53 functions, while E7 impedes the retinoblastoma (Rb) protein, altering E2F transcription factor activities. This miRNA dysregulation plays a crucial role in cancer progression by affecting multiple signaling pathways. Specifically, miR-34a and miR-145 suppress androgen receptor (AR) levels, and miR-21, miR-106a, and the miR-221/222 cluster target PTEN, leading to activation of the PI3K/AKT/mTOR pathway. These alterations enhance cellular proliferation, invasion, epithelial-mesenchymal transition (EMT), and metastasis. Importantly, let-7c and miR-143 downregulate the PI3K/AKT pathway, mitigating tumor growth. Moreover, miR-21 and the miR-221/222 cluster also interact with the JAK/STAT pathway, where they influence inflammatory and immune responses, further contributing to prostate cancer progression. Collectively, miRNAs are pivotal in mediating HPV’s oncogenic effects in prostate cancer by regulating essential signaling pathways, highlighting their potential as both biomarkers and therapeutic targets in the management of the disease.
Table 1.
Histopathology stratification of selected prostate samples.
Table 1.
Histopathology stratification of selected prostate samples.
Histopathological diagnosis |
Number of samples |
Healthy tissues (HPV-negative tissue biopsy) |
14 |
BPH |
13 |
BPH / Prostatitis |
37 |
PCa |
33 |
Gleason (8-10) (High degree of malignancy) |
21 |
Gleason (7) (Intermediate degree of malignancy) |
3 |
Gleason <6 (Low degree of malignancy) |
9 |
Table 2.
HPV Genotype frequency in benign and PCa lesions, according to the type and injury degree in the prostate gland.
Table 2.
HPV Genotype frequency in benign and PCa lesions, according to the type and injury degree in the prostate gland.
Type of injury |
HPV positivity frequency (%) |
Predominant HPV genotypes |
Coinfection [1]
|
Benign lesions |
67.2 |
6, 11 |
|
Malignant lesions |
93.4 |
16, 18, 31,33, 52, 58 |
|
HPV genotypes in benign lesions group |
BPH |
LR: 62.5 |
6,11 |
ND |
IR: 25.0 |
52,58 |
6,11 |
HR: 12.5 |
16,18 |
6, 11, 33 |
BPH/Prostatitis |
LR:74 |
6, 11 |
ND |
IR: 21.7 |
52,58 |
6,11 |
HR: 4.3 |
16, 18 |
6,11,33 |
HPV genotypes in PCa group |
Low risk cancer |
29.7 |
6, 11 |
|
Intermediate risk cancer |
9.1 |
31, 33, 52, 58 |
|
High risk cancer |
61.2 |
16, 18 |
|
HPV genotypes depending on PCa Gleason stratification |
Grade Gleason score < 6
|
LR-HPV: 55.5 |
6, 11 |
58, 52[1]
|
IR-HPV: 11.1 |
52 |
16 |
HR-HPV: 33.3 |
16 |
ND |
Grade Gleason 7 |
LR-HPV: ND |
ND |
ND |
IR-HPV: 66.67 |
31,58 |
16 |
HR-HPV: 33.33 |
18 |
ND |
Grade Gleason 8 - 9 |
LR-HPV: 10.6 |
6, 11 |
31, 52 |
IR-HPV: 47.3 |
33, 31, 52 |
18 |
HR-HPV: 42.10 |
16, 18 |
6 |