Tropomyosins: Potential Biomarkers for Urothelial Bladder Cancer

The authors summarized roles of tropomyosin in urothelial   carcinomas and discussed its potential usefulness as the biomarker. Some   isotypes of tropomyosin are involved in cancer cell survival, proliferation   and migration according to cancer stage. In bladder cancer, molecules   detectable in urine sample may be ideal substances that can be used as   biomarkers. They suggested that not quantification, but detection of isoform   of tropomyosin mRNA in urine sample may be useful as a biomarker. This   suggestion is unique and relevant, which is desired to be verified by further   investigations.

In bladder cancer, as the authors described, development   of better non-invasive biomarkers has been desired, which can replace   cystoscopy. Investigators should explore every possibility. Therefore, this   review may be meaningful.

Structure of the text and figures are organized and easy   to read.

1

Thank   you for your feedback

N/A

The rationale for focusing on tropomyosin needs to be   stated earlier in the manuscript. Including this sooner (e.g. a few sentences   at the end of the introduction) would likely help engage more readers.

2

use of   Tropomyosin (TPM) in the detection and stratification of bladder cancer. Tropomyosins perform isoform   specific functions within normal cells of the urothelium, and alteration in   the isoform expression and concomitant spliceform switching can be observed   in the event of bladder carcinogenesis, as will be discussed later (Section   4).

51-54

The   authors should note that the highest levels of tropomyosin are found in   muscle cells. More focus needs to be placed on describing the expression   levels/role of tropomyosin in the different types of muscle cells – as is,   too much of the review focuses on describing its role in non-muscle cells.

2

contractile   function within skeletal and cardiac muscle [12]. It is found to be a key regulator in the   excitation-contraction coupling mechanism involved within skeletal muscle   that allows synchronous movements of the myosin heads with the corresponding   actin filaments. Though tropomyosins are largely seen to be part of muscle   cells, their functions are not limited to muscle cells alone.

Furthermore, Section 7, Figure   2 illustrates the presence of tropomyosin in other body tissues alongside its   presence in urine.

Aside from urine, the frequency of TPMs is much higher and detectable in   exosomes of cells and other biofluids (Figure   2).

However   this review focuses on the significance of Tropomyosin within non-skeletal   muscle cells. Also, given that the majority of bladder cancer cases are   non-muscle invasive, we would like to keep the focus on non-muscle invasive   disease.

58-61

  303-304

To follow-up on this point, I encourage the authors to   consider the possibility that tropomyosin may be released into body fluids as   a result of muscle invasion – perhaps increased levels of tropomyosin could   occur due to increased muscle cell death and/or increased exosome release   that occurs as a result of disruption of the smooth muscle layer which   underlies the bladder. As an aside, the authors may also consider noting that   troponin, a binding partner of tropomyosin, is used as a biomarker to assess   cardiac injury.

2

and admixture  of other protein/RNA species. Furthermore, due to their   abundance within skeletal and cardiac muscle as noted earlier, it could be   hypothesized that the secretion or release of TPM isoforms within urinary   exosomes could be indicative of breach of the basement membrane and invasion   into and beyond the muscular layer of the bladder wall.

280-283

Consider   using replacing the word ‘cardinal’    (line 24); some readers may not be familiar with this word

2

Each year   c.100,000 patients in the UK undergo investigation for haematuria, the commonest symptom of   urothelial bladder cancer (UBC).

24

Define   the acronyms TURBT and MIBC after they are first mentioned in the text  (line 28)

2

diagnosed with   UBC [1], of which 75-80% will have non-muscle-invasive disease (NMIBC: stages Ta/T1/Tis) [2]. The   remaining 20-25% of patients are diagnosed with muscle-invasive disease (MIBC: stages T2+)   following TURBT-   Transurethral Resection of Bladder Tumour, and undergo further staging   investigations before receiving definitive treatment.

26-28

It would   be helpful if the authors related information in sections 2.1 and 2.3 to   cancer. E.g. Are different isoforms found in normal versus cancer cells, or   are there increases in expression levels which occur during carcinogenesis?   Relating the information provided in these sections to cancer would help   engage readers (perhaps some information from later sections can be   integrated here? My concern is that these earlier sections are quite long and   a little ‘dry’).        

2

Section   2.2 briefly sheds light onto the implications of isoform expression levels in   the development of carcinogenesis

proliferation,   migration and invasion [13]. As   we see in Section 5 and Section 8, isoform usage and expression levels change   during carcinogenesis in tissue-specific patterns, highlighting the   complexity of TPM gene and splicing regulation.

68-70

This   review is interesting and shows important aspects to new biomarkers for   urinary bladder cancer. As review I would like to see more references. But in   general, there are no special complains .

3

TPMs in   Bladder cancer is a relatively unexplored entity. Therefore, we are limited   to the literature available that is of relevance pertaining to the review.   Much work is still to be discovered.

N/A

The authors summarized roles of tropomyosin in urothelial   carcinomas and discussed its potential usefulness as the biomarker. Some   isotypes of tropomyosin are involved in cancer cell survival, proliferation   and migration according to cancer stage. In bladder cancer, molecules   detectable in urine sample may be ideal substances that can be used as   biomarkers. They suggested that not quantification, but detection of isoform   of tropomyosin mRNA in urine sample may be useful as a biomarker. This   suggestion is unique and relevant, which is desired to be verified by further   investigations.

In bladder cancer, as the authors described, development   of better non-invasive biomarkers has been desired, which can replace   cystoscopy. Investigators should explore every possibility. Therefore, this   review may be meaningful.

Structure of the text and figures are organized and easy   to read.

1

Thank   you for your feedback

N/A

The rationale for focusing on tropomyosin needs to be   stated earlier in the manuscript. Including this sooner (e.g. a few sentences   at the end of the introduction) would likely help engage more readers.

2

use of   Tropomyosin (TPM) in the detection and stratification of bladder cancer. Tropomyosins perform isoform   specific functions within normal cells of the urothelium, and alteration in   the isoform expression and concomitant spliceform switching can be observed   in the event of bladder carcinogenesis, as will be discussed later (Section   4).

51-54

The   authors should note that the highest levels of tropomyosin are found in   muscle cells. More focus needs to be placed on describing the expression   levels/role of tropomyosin in the different types of muscle cells – as is,   too much of the review focuses on describing its role in non-muscle cells.

2

contractile   function within skeletal and cardiac muscle [12]. It is found to be a key regulator in the   excitation-contraction coupling mechanism involved within skeletal muscle   that allows synchronous movements of the myosin heads with the corresponding   actin filaments. Though tropomyosins are largely seen to be part of muscle   cells, their functions are not limited to muscle cells alone.

Furthermore, Section 7, Figure   2 illustrates the presence of tropomyosin in other body tissues alongside its   presence in urine.

Aside from urine, the frequency of TPMs is much higher and detectable in   exosomes of cells and other biofluids (Figure   2).

However   this review focuses on the significance of Tropomyosin within non-skeletal   muscle cells. Also, given that the majority of bladder cancer cases are   non-muscle invasive, we would like to keep the focus on non-muscle invasive   disease.

58-61

  303-304

To follow-up on this point, I encourage the authors to   consider the possibility that tropomyosin may be released into body fluids as   a result of muscle invasion – perhaps increased levels of tropomyosin could   occur due to increased muscle cell death and/or increased exosome release   that occurs as a result of disruption of the smooth muscle layer which   underlies the bladder. As an aside, the authors may also consider noting that   troponin, a binding partner of tropomyosin, is used as a biomarker to assess   cardiac injury.

2

and admixture  of other protein/RNA species. Furthermore, due to their   abundance within skeletal and cardiac muscle as noted earlier, it could be   hypothesized that the secretion or release of TPM isoforms within urinary   exosomes could be indicative of breach of the basement membrane and invasion   into and beyond the muscular layer of the bladder wall.

280-283

Consider   using replacing the word ‘cardinal’    (line 24); some readers may not be familiar with this word

2

Each year   c.100,000 patients in the UK undergo investigation for haematuria, the commonest symptom of   urothelial bladder cancer (UBC).

24

Define   the acronyms TURBT and MIBC after they are first mentioned in the text  (line 28)

2

diagnosed with   UBC [1], of which 75-80% will have non-muscle-invasive disease (NMIBC: stages Ta/T1/Tis) [2]. The   remaining 20-25% of patients are diagnosed with muscle-invasive disease (MIBC: stages T2+)   following TURBT-   Transurethral Resection of Bladder Tumour, and undergo further staging   investigations before receiving definitive treatment.

26-28

It would   be helpful if the authors related information in sections 2.1 and 2.3 to   cancer. E.g. Are different isoforms found in normal versus cancer cells, or   are there increases in expression levels which occur during carcinogenesis?   Relating the information provided in these sections to cancer would help   engage readers (perhaps some information from later sections can be   integrated here? My concern is that these earlier sections are quite long and   a little ‘dry’).        

2

Section   2.2 briefly sheds light onto the implications of isoform expression levels in   the development of carcinogenesis

proliferation,   migration and invasion [13]. As   we see in Section 5 and Section 8, isoform usage and expression levels change   during carcinogenesis in tissue-specific patterns, highlighting the   complexity of TPM gene and splicing regulation.

68-70

This   review is interesting and shows important aspects to new biomarkers for   urinary bladder cancer. As review I would like to see more references. But in   general, there are no special complains .

3

TPMs in   Bladder cancer is a relatively unexplored entity. Therefore, we are limited   to the literature available that is of relevance pertaining to the review.   Much work is still to be discovered.

N/A

The authors summarized roles of tropomyosin in urothelial   carcinomas and discussed its potential usefulness as the biomarker. Some   isotypes of tropomyosin are involved in cancer cell survival, proliferation   and migration according to cancer stage. In bladder cancer, molecules   detectable in urine sample may be ideal substances that can be used as   biomarkers. They suggested that not quantification, but detection of isoform   of tropomyosin mRNA in urine sample may be useful as a biomarker. This   suggestion is unique and relevant, which is desired to be verified by further   investigations.

In bladder cancer, as the authors described, development   of better non-invasive biomarkers has been desired, which can replace   cystoscopy. Investigators should explore every possibility. Therefore, this   review may be meaningful.

Structure of the text and figures are organized and easy   to read.

1

Thank   you for your feedback

N/A

The rationale for focusing on tropomyosin needs to be   stated earlier in the manuscript. Including this sooner (e.g. a few sentences   at the end of the introduction) would likely help engage more readers.

2

use of   Tropomyosin (TPM) in the detection and stratification of bladder cancer. Tropomyosins perform isoform   specific functions within normal cells of the urothelium, and alteration in   the isoform expression and concomitant spliceform switching can be observed   in the event of bladder carcinogenesis, as will be discussed later (Section   4).

51-54

The   authors should note that the highest levels of tropomyosin are found in   muscle cells. More focus needs to be placed on describing the expression   levels/role of tropomyosin in the different types of muscle cells – as is,   too much of the review focuses on describing its role in non-muscle cells.

2

contractile   function within skeletal and cardiac muscle [12]. It is found to be a key regulator in the   excitation-contraction coupling mechanism involved within skeletal muscle   that allows synchronous movements of the myosin heads with the corresponding   actin filaments. Though tropomyosins are largely seen to be part of muscle   cells, their functions are not limited to muscle cells alone.

Furthermore, Section 7, Figure   2 illustrates the presence of tropomyosin in other body tissues alongside its   presence in urine.

Aside from urine, the frequency of TPMs is much higher and detectable in   exosomes of cells and other biofluids (Figure   2).

However   this review focuses on the significance of Tropomyosin within non-skeletal   muscle cells. Also, given that the majority of bladder cancer cases are   non-muscle invasive, we would like to keep the focus on non-muscle invasive   disease.

58-61

  303-304

To follow-up on this point, I encourage the authors to   consider the possibility that tropomyosin may be released into body fluids as   a result of muscle invasion – perhaps increased levels of tropomyosin could   occur due to increased muscle cell death and/or increased exosome release   that occurs as a result of disruption of the smooth muscle layer which   underlies the bladder. As an aside, the authors may also consider noting that   troponin, a binding partner of tropomyosin, is used as a biomarker to assess   cardiac injury.

2

and admixture  of other protein/RNA species. Furthermore, due to their   abundance within skeletal and cardiac muscle as noted earlier, it could be   hypothesized that the secretion or release of TPM isoforms within urinary   exosomes could be indicative of breach of the basement membrane and invasion   into and beyond the muscular layer of the bladder wall.

280-283

Consider   using replacing the word ‘cardinal’    (line 24); some readers may not be familiar with this word

2

Each year   c.100,000 patients in the UK undergo investigation for haematuria, the commonest symptom of   urothelial bladder cancer (UBC).

24

Define   the acronyms TURBT and MIBC after they are first mentioned in the text  (line 28)

2

diagnosed with   UBC [1], of which 75-80% will have non-muscle-invasive disease (NMIBC: stages Ta/T1/Tis) [2]. The   remaining 20-25% of patients are diagnosed with muscle-invasive disease (MIBC: stages T2+)   following TURBT-   Transurethral Resection of Bladder Tumour, and undergo further staging   investigations before receiving definitive treatment.

26-28

It would   be helpful if the authors related information in sections 2.1 and 2.3 to   cancer. E.g. Are different isoforms found in normal versus cancer cells, or   are there increases in expression levels which occur during carcinogenesis?   Relating the information provided in these sections to cancer would help   engage readers (perhaps some information from later sections can be   integrated here? My concern is that these earlier sections are quite long and   a little ‘dry’).        

2

Section   2.2 briefly sheds light onto the implications of isoform expression levels in   the development of carcinogenesis

proliferation,   migration and invasion [13]. As   we see in Section 5 and Section 8, isoform usage and expression levels change   during carcinogenesis in tissue-specific patterns, highlighting the   complexity of TPM gene and splicing regulation.

68-70

This   review is interesting and shows important aspects to new biomarkers for   urinary bladder cancer. As review I would like to see more references. But in   general, there are no special complains .

3

TPMs in   Bladder cancer is a relatively unexplored entity. Therefore, we are limited   to the literature available that is of relevance pertaining to the review.   Much work is still to be discovered.

N/A